EXECUTION 


    STRUCTURED
      ASSET SECURITIES CORPORATION,

    as
      Depositor,

     

     

    AURORA
      LOAN SERVICES LLC,

    as
      Master
      Servicer,

     

     

    CLAYTON
      FIXED INCOME SERVICES INC., as Credit Risk Manager

     

     

    and

     

     

    CITIBANK,
      N.A.,

    as
      Trustee

     

     

      
        

      

    

    TRUST
      AGREEMENT

    


     

    Dated
      as
      of December
      1, 2006

    
      

    

     

     

    STRUCTURED
      ASSET SECURITIES CORPORATION

    MORTGAGE
      PASS-THROUGH CERTIFICATES,

    SERIES
      2006-S4

    


    


    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    


    TABLE
      OF
      CONTENTS

    

      
        	 	
                     

              	 	
                     

              	
                Page

              
	 	 	 
	
                ARTICLE
                  I
                  DEFINITIONS

              	 	
                13

              
	 	 	 	 	 
	
                Section
                  1.01

              	 	
                Definitions.

              	 	
                13

              
	
                Section
                  1.02

              	 	
                Calculations
                  Respecting Mortgage Loans.

              	 	
                50

              
	
                Section
                  1.03

              	 	
                Calculations
                  Respecting Accrued Interest.

              	 	
                50

              
	 	 	 
	
                ARTICLE
                  II
                  DECLARATION OF TRUST; ISSUANCE OF CERTIFICATES

              	 	
                51

              
	 	 	 
	
                Section
                  2.01

              	 	
                Creation
                  and Declaration of Trust Fund; Conveyance of Mortgage
                  Loans.

              	 	
                51

              
	
                Section
                  2.02

              	 	
                Acceptance
                  of Trust Fund by Trustee: Review of Documentation for Trust
                  Fund.

              	 	
                55

              
	
                Section
                  2.03

              	 	
                Representations
                  and Warranties of the Depositor.

              	 	
                56

              
	
                Section
                  2.04

              	 	
                Discovery
                  of Breach.

              	 	
                58

              
	
                Section
                  2.05

              	 	
                Repurchase,
                  Purchase or Substitution of Mortgage Loans.

              	 	
                58

              
	
                Section
                  2.06

              	 	
                Grant
                  Clause.

              	 	
                60

              
	 	 	 
	
                ARTICLE
                  III
                  THE CERTIFICATES

              	 	
                61

              
	 	 	 
	
                Section
                  3.01

              	 	
                The
                  Certificates.

              	 	
                61

              
	
                Section
                  3.02

              	 	
                Registration.

              	 	
                62

              
	
                Section
                  3.03

              	 	
                Transfer
                  and Exchange of Certificates.

              	 	
                63

              
	
                Section
                  3.04

              	 	
                Cancellation
                  of Certificates.

              	 	
                68

              
	
                Section
                  3.05

              	 	
                Replacement
                  of Certificates.

              	 	
                69

              
	
                Section
                  3.06

              	 	
                Persons
                  Deemed Owners.

              	 	
                69

              
	
                Section
                  3.07

              	 	
                Temporary
                  Certificates.

              	 	
                69

              
	
                Section
                  3.08

              	 	
                Appointment
                  of Paying Agent.

              	 	
                70

              
	
                Section
                  3.09

              	 	
                Book-Entry
                  Certificates.

              	 	
                70

              
	 	 	 
	
                ARTICLE
                  IV
                  ADMINISTRATION OF THE TRUST FUND

              	 	
                71

              
	 	 	 
	
                Section
                  4.01

              	 	
                Collection
                  Account.

              	 	
                71

              
	
                Section
                  4.02

              	 	
                Application
                  of Funds in the Collection Account.

              	 	
                73

              
	
                Section
                  4.03

              	 	
                Reports
                  to Certificateholders.

              	 	
                75

              
	
                Section
                  4.04

              	 	
                Certificate
                  Account.

              	 	
                79

              
	 	 	 
	
                ARTICLE
                  V
                  DISTRIBUTIONS TO HOLDERS OF CERTIFICATES

              	 	
                80

              
	 	 	 
	
                Section
                  5.01

              	 	
                Distributions
                  Generally.

              	 	
                80

              
	
                Section
                  5.02

              	 	
                Distributions
                  from the Certificate Account.

              	 	
                81

              
	
                Section
                  5.03

              	 	
                Allocation
                  of Losses.

              	 	
                90

              
	
                Section
                  5.04

              	 	
                Advances
                  by Master Servicer, Servicer and Trustee.

              	 	
                90

              
	
                Section
                  5.05

              	 	
                Compensating
                  Interest Payments.

              	 	
                91

              
	
                Section
                  5.06

              	 	
                Basis
                  Risk Reserve Fund.

              	 	
                92

              
	
                Section
                  5.07

              	 	
                Supplemental
                  Interest Trust.

              	 	
                92

              
	
                Section
                  5.08

              	 	
                Rights
                  of Swap Counterparty.

              	 	
                94

              


      

       

      
        
          
          

        

        
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                Section
                  5.09

              	 	
                Termination
                  Receipts.

              	 	
                95

              
	 	 	 
	
                ARTICLE
                  VI
                  CONCERNING THE TRUSTEE EVENTS OF DEFAULT

              	 	
                96

              
	 	 	 
	
                Section
                  6.01

              	 	
                Duties
                  of Trustee.

              	 	
                96

              
	
                Section
                  6.02

              	 	
                Certain
                  Matters Affecting the Trustee .

              	 	
                100

              
	
                Section
                  6.03

              	 	
                Trustee
                  Not Liable for Certificates.

              	 	
                101

              
	
                Section
                  6.04

              	 	
                Trustee
                  May Own Certificates.

              	 	
                101

              
	
                Section
                  6.05

              	 	
                Eligibility
                  Requirements for Trustee.

              	 	
                101

              
	
                Section
                  6.06

              	 	
                Resignation
                  and Removal of Trustee.

              	 	
                102

              
	
                Section
                  6.07

              	 	
                Successor
                  Trustee.

              	 	
                103

              
	
                Section
                  6.08

              	 	
                Merger
                  or Consolidation of Trustee.

              	 	
                103

              
	
                Section
                  6.09

              	 	
                Appointment
                  of Co-Trustee, Separate Trustee or Custodian.

              	 	
                104

              
	
                Section
                  6.10

              	 	
                Authenticating
                  Agents.

              	 	
                105

              
	
                Section
                  6.11

              	 	
                Indemnification
                  of Trustee.

              	 	
                106

              
	
                Section
                  6.12

              	 	
                Fees
                  and Expenses of Trustee and Custodians.

              	 	
                107

              
	
                Section
                  6.13

              	 	
                Collection
                  of Monies.

              	 	
                107

              
	
                Section
                  6.14

              	 	
                Events
                  of Default; Trustee To Act; Appointment of Successor.

              	 	
                108

              
	
                Section
                  6.15

              	 	
                Additional
                  Remedies of Trustee Upon Event of Default.

              	 	
                112

              
	
                Section
                  6.16

              	 	
                Waiver
                  of Defaults.

              	 	
                112

              
	
                Section
                  6.17

              	 	
                Notification
                  to Holders.

              	 	
                112

              
	
                Section
                  6.18

              	 	
                Directions
                  by Certificateholders and Duties of Trustee During Event of
                  Default.

              	 	
                113

              
	
                Section
                  6.19

              	 	
                Action
                  Upon Certain Failures of the Master Servicer and Upon Event of
                  Default.

              	 	
                113

              
	
                Section
                  6.20

              	 	
                Preparation
                  of Tax Returns and Other Reports.

              	 	
                113

              
	
                Section
                  6.21

              	 	
                Compliance
                  with Regulation AB.

              	 	
                121

              
	 	 	 
	
                ARTICLE
                  VII
                  PURCHASE OF MORTGAGE LOANS AND TERMINATION OF THE TRUST
                  FUND

              	 	
                121

              
	 	 	 
	
                Section
                  7.01

              	 	
                Purchase
                  of Mortgage Loans; Termination of Trust Fund Upon Purchase or Liquidation
                  of All Mortgage Loans; Purchase of Lower Tier REMIC 1 Uncertificated
                  Regular Interests.

              	 	
                121

              
	
                Section
                  7.02

              	 	
                Procedure
                  Upon Termination of Trust Fund or Purchase of Lower Tier REMIC
                  1
                  Uncertificated Regular Interests.

              	 	
                123

              
	
                Section
                  7.03

              	 	
                Additional
                  Trust Fund Termination Event or Purchase of the Lower Tier REMIC 1
                  Uncertificated Regular Interests.

              	 	
                124

              
	
                Section
                  7.04

              	 	
                Charged-off
                  Loans and Released Mortgage Loans.

              	 	
                125

              
	 	 	 
	
                ARTICLE
                  VIII
                  RIGHTS OF CERTIFICATEHOLDERS

              	 	
                126

              
	 	 	 
	
                Section
                  8.01

              	 	
                Limitation
                  on Rights of Holders.

              	 	
                126

              
	
                Section
                  8.02

              	 	
                Access
                  to List of Holders.

              	 	
                127

              
	
                Section
                  8.03

              	 	
                Acts
                  of Holders of Certificates.

              	 	
                127

              


      

       

      
        
          
          

        

        
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                ARTICLE
                  IX
                  ADMINISTRATION AND SERVICING OF MORTGAGE LOANS BY THE MASTER SERVICER;
                  CREDIT RISK MANAGER

              	 	
                128

              
	 	 	 
	
                Section
                  9.01

              	 	
                Duties
                  of the Master Servicer.

              	 	
                128

              
	
                Section
                  9.02

              	 	
                Master
                  Servicer Fidelity Bond and Master Servicer Errors and Omissions
                  Insurance
                  Policy.

              	 	
                128

              
	
                Section
                  9.03

              	 	
                Master
                  Servicer’s Financial Statements and Related Information.

              	 	
                129

              
	
                Section
                  9.04

              	 	
                Power
                  to Act; Procedures.

              	 	
                129

              
	
                Section
                  9.05

              	 	
                Enforcement
                  of Servicer’s and Master Servicer’s Obligations.

              	 	
                132

              
	
                Section
                  9.06

              	 	
                Collection
                  of Taxes, Assessments and Similar Items.

              	 	
                132

              
	
                Section
                  9.07

              	 	
                Termination
                  of Servicing Agreement; Successor Servicers.

              	 	
                133

              
	
                Section
                  9.08

              	 	
                Master
                  Servicer Liable for Enforcement.

              	 	
                134

              
	
                Section
                  9.09

              	 	
                No
                  Contractual Relationship Between the Servicer and Trustee or
                  Depositor.

              	 	
                134

              
	
                Section
                  9.10

              	 	
                Assumption
                  of Servicing Agreement by Trustee.

              	 	
                134

              
	
                Section
                  9.11

              	 	
                Due-on-Sale
                  Clauses; Assumption Agreements.

              	 	
                135

              
	
                Section
                  9.12

              	 	
                Release
                  of Mortgage Files.

              	 	
                135

              
	
                Section
                  9.13

              	 	
                Documents,
                  Records and Funds in Possession of Master Servicer to be Held for
                  Trustee.

              	 	
                136

              
	
                Section
                  9.14

              	 	
                Representations
                  and Warranties of the Master Servicer.

              	 	
                137

              
	
                Section
                  9.15

              	 	
                Opinion.

              	 	
                140

              
	
                Section
                  9.16

              	 	
                Standard
                  Hazard and Flood Insurance Policies.

              	 	
                140

              
	
                Section
                  9.17

              	 	
                Presentment
                  of Claims and Collection of Proceeds.

              	 	
                140

              
	
                Section
                  9.18

              	 	
                [Reserved]

              	 	
                141

              
	
                Section
                  9.19

              	 	
                [Reserved]

              	 	
                141

              
	
                Section
                  9.20

              	 	
                [Reserved]

              	 	
                141

              
	
                Section
                  9.21

              	 	
                Compensation
                  to the Master Servicer.

              	 	
                141

              
	
                Section
                  9.22

              	 	
                REO
                  Property.

              	 	
                141

              
	
                Section
                  9.23

              	 	
                Notice
                  to the Sponsor, the Depositor and the Trustee.

              	 	
                142

              
	
                Section
                  9.24

              	 	
                Reports
                  to the Trustee.

              	 	
                142

              
	
                Section
                  9.25

              	 	
                Assessment
                  of Compliance and Attestation Reports.

              	 	
                143

              
	
                Section
                  9.26

              	 	
                Annual
                  Statement of Compliance with Applicable Servicing
                  Criteria.

              	 	
                144

              
	
                Section
                  9.27

              	 	
                Merger
                  or Consolidation.

              	 	
                145

              
	
                Section
                  9.28

              	 	
                Resignation
                  of Master Servicer.

              	 	
                145

              
	
                Section
                  9.29

              	 	
                Assignment
                  or Delegation of Duties by the Master Servicer.

              	 	
                145

              
	
                Section
                  9.30

              	 	
                Limitation
                  on Liability of the Master Servicer and Others.

              	 	
                146

              
	
                Section
                  9.31

              	 	
                Indemnification;
                  Third-Party Claims.

              	 	
                147

              
	
                Section
                  9.32

              	 	
                [Reserved]

              	 	
                147

              
	
                Section
                  9.33

              	 	
                [Reserved]

              	 	
                147

              
	
                Section
                  9.34

              	 	
                Duties
                  of the Credit Risk Manager.

              	 	
                147

              
	
                Section
                  9.35

              	 	
                Limitation
                  Upon Liability of the Credit Risk Manager.

              	 	
                149

              
	
                Section
                  9.36

              	 	
                Indemnification
                  by the Credit Risk Manager.

              	 	
                150

              
	
                Section
                  9.37

              	 	
                Removal
                  of Credit Risk Manager.

              	 	
                150

              
	 	 	 
	
                ARTICLE
                  X
                  REMIC ADMINISTRATION

              	 	
                150

              
	 	 	 
	
                Section
                  10.01

              	 	
                REMIC
                  Administration.

              	 	
                150

              
	
                Section
                  10.02

              	 	
                Prohibited
                  Transactions and Activities.

              	 	
                153

              


      

       

      
        
          
          

        

        
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                Section
                  10.03

              	 	
                Indemnification
                  with Respect to Certain Taxes and Loss of REMIC Status.

              	 	
                154

              
	
                Section
                  10.04

              	 	
                REO
                  Property.

              	 	
                154

              
	 	 	 
	
                ARTICLE
                  XI
                  MISCELLANEOUS PROVISIONS

              	 	
                155

              
	 	 	 
	
                Section
                  11.01

              	 	
                Binding
                  Nature of Agreement; Assignment.

              	 	
                155

              
	
                Section
                  11.02

              	 	
                Entire
                  Agreement.

              	 	
                155

              
	
                Section
                  11.03

              	 	
                Amendment.

              	 	
                155

              
	
                Section
                  11.04

              	 	
                Voting
                  Rights.

              	 	
                157

              
	
                Section
                  11.05

              	 	
                Provision
                  of Information.

              	 	
                157

              
	
                Section
                  11.06 

              	 	
                Governing
                  Law.

              	 	
                158

              
	
                Section
                  11.07

              	 	
                Notices.

              	 	
                158

              
	
                Section
                  11.08

              	 	
                Severability
                  of Provisions.

              	 	
                158

              
	
                Section
                  11.09

              	 	
                Indulgences;
                  No Waivers.

              	 	
                158

              
	
                Section
                  11.10

              	 	
                Headings
                  Not To Affect Interpretation.

              	 	
                159

              
	
                Section
                  11.11

              	 	
                [Reserved].

              	 	
                159

              
	
                Section
                  11.12

              	 	
                Special
                  Notices to the Rating Agencies.

              	 	
                159

              
	
                Section
                  11.13

              	 	
                Conflicts.

              	 	
                160

              
	
                Section
                  11.14

              	 	
                Counterparts.

              	 	
                160

              
	
                Section
                  11.15

              	 	
                Transfer
                  of Servicing.

              	 	
                160

              


      

    


    
      
        
        

      

      
        iv

        
          

        

      

      
        
        

      

    


    ATTACHMENTS

    

      
        	
                Exhibit
                  A-1

              	
                Form
                  of Senior Certificate

              
	
                Exhibit
                  A-2

              	
                Form
                  of Class M Certificate

              
	
                Exhibit
                  A-3

              	
                Form
                  of Class B Certificate

              
	
                Exhibit
                  A-4

              	
                Form
                  of Class P Certificate

              
	
                Exhibit
                  A-5

              	
                Form
                  of Class X Certificate

              
	
                Exhibit
                  A-6

              	
                Form
                  of Residual Certificate

              
	
                Exhibit
                  A-7

              	
                Form
                  of Reverse of Certificate

              
	
                Exhibit
                  B-1

              	
                Form
                  of Initial Certification

              
	
                Exhibit
                  B-2

              	
                Form
                  of Interim Certification

              
	
                Exhibit
                  B-3

              	
                Form
                  of Final Certification

              
	
                Exhibit
                  B-4

              	
                Form
                  of Endorsement

              
	
                Exhibit
                  C

              	
                Request
                  for Release of Documents and Receipt

              
	
                Exhibit
                  D-1

              	
                Form
                  of Residual Certificate Transfer Affidavit (Transferee)

              
	
                Exhibit
                  D-2

              	
                Form
                  of Residual Certificate Transfer Affidavit (Transferor)

              
	
                Exhibit
                  E

              	
                List
                  of Servicing Agreements

              
	
                Exhibit
                  F

              	
                Form
                  of Rule 144A Transfer Certificate

              
	
                Exhibit
                  G

              	
                Form
                  of Purchaser’s Letter for Institutional Accredited
                  Investors

              
	
                Exhibit
                  H

              	
                Form
                  of ERISA Transfer Affidavit

              
	
                Exhibit
                  I

              	
                [Reserved]

              
	
                Exhibit
                  J

              	
                [Reserved]

              
	
                Exhibit
                  K

              	
                List
                  of Custodial Agreements

              
	
                Exhibit
                  L

              	
                List
                  of Credit Risk Management Agreements 

              
	
                Exhibit
                  M

              	
                Form
                  of Back-up Certification to be Provided by the Trustee to the Depositor
                  and/or the Master Servicer

              
	
                Exhibit
                  N-1

              	
                Form
                  of Transfer Certificate for Transfer from Restricted Global Security
                  to
                  Regulation S Global Security

              
	
                Exhibit
                  N-2 

              	
                Form
                  of Transfer Certificate for Transfer from Regulation S Global Security
                  to
                  Restricted Global Security

              
	
                Exhibit
                  O

              	
                [Reserved]

              
	
                Exhibit
                  P

              	
                Swap
                  Agreement

              
	
                Exhibit
                  Q

              	
                [Reserved]

              
	
                Exhibit
                  R

              	
                [Reserved]
                  

              
	
                Exhibit
                  S-1

              	
                Form
                  of Watchlist Report

              
	
                Exhibit
                  S-2

              	
                Form
                  of Loss Severity Report

              
	
                Exhibit
                  S-3

              	
                Form
                  of Prepayment Premiums Report

              
	
                Exhibit
                  S-4

              	
                Form
                  of Analytics Report

              
	
                Exhibit
                  T

              	
                Servicing
                  Criteria to be Addressed in Report on Assessment of
                  Compliance

              
	
                Exhibit
                  U

              	
                Form
                  of Certification to be Provided by the Credit Risk
                  Manager

              
	
                Exhibit
                  V

              	
                Transaction
                  Parties 

              
	 	 
	
                Schedule
                  A

              	
                Mortgage
                  Loan Schedule

              
	
                Schedule
                  B

              	
                First
                  Payment Default Mortgage
                  Loans

              


      

    

     

    
      
        
        

      

      
        v

        
          

        

      

      
        
        

      

    

     

    This
      TRUST AGREEMENT (“Trust Agreement”) dated as of December 1,
      2006 (the “Agreement”), is by and among STRUCTURED ASSET SECURITIES CORPORATION,
      a Delaware corporation, as depositor (the “Depositor”), AURORA LOAN SERVICES
      LLC, as master servicer (the “Master Servicer”), CITIBANK, N.A., a national
      banking association, as trustee (the “Trustee”), and CLAYTON FIXED INCOME
      SERVICES INC., a Colorado corporation, as credit risk manager (the “Credit Risk
      Manager”). 

     

    PRELIMINARY
      STATEMENT 

     

    The
      Depositor has acquired the Mortgage Loans from the Seller, and at the Closing
      Date is the owner of the Mortgage Loans and the other property being conveyed
      by
      it to the Trustee hereunder for inclusion in the Trust Fund. On the Closing
      Date, the Depositor will acquire the Certificates from the Trust Fund as
      consideration for its transfer to the Trust Fund of the Mortgage Loans and
      the
      other property constituting the Trust Fund. The Depositor has duly authorized
      the execution and delivery of this Agreement to provide for the conveyance
      to
      the Trustee of the Mortgage Loans and the other property constituting the Trust
      Fund. All covenants and agreements made by the Seller in the Mortgage Loan
      Sale
      Agreement and by the Depositor, the Master Servicer and the Trustee herein
      with
      respect to the Mortgage Loans and the other property constituting the Trust
      Fund
      are for the benefit of the Holders from time to time of the Certificates and,
      to
      the extent provided herein, the Swap Counterparty. The Depositor, the Trustee,
      the Master Servicer and the Credit Risk Manager are entering into this
      Agreement, and the Trustee is accepting the Trust Fund created hereby, for
      good
      and valuable consideration, the receipt and sufficiency of which are hereby
      acknowledged.

     

    As
      provided herein, an election shall be made that the Trust Fund (exclusive of
      (i)
      the Swap Agreement, (ii) the Swap Account, (iii) the right to receive and the
      obligation to pay Basis Risk Shortfalls and Unpaid Basis Risk Shortfalls, (iv)
      the Basis Risk Reserve Fund, (v), the Supplemental Interest Trust, (vi) the
      obligation to pay Class I Shortfalls and (vii) the Collateral Account
      (collectively, the “Excluded Trust Assets”)) be treated for federal income tax
      purposes as comprising four real estate mortgage investment conduits under
      Section 860D of the Code (each a “REMIC” or, in the alternative “REMIC 1,”
“REMIC 2,” “REMIC 3,” and “REMIC 4” (REMIC 4 also being
      referred to as the “Upper Tier REMIC”)). Any inconsistencies or ambiguities in
      this Agreement or in the administration of this Agreement shall be resolved
      in a
      manner that preserves the validity of such REMIC elections.

     

    Each
      Certificate, other than the Class R and Class LT-R Certificates, represents
      ownership of a regular interest in the Upper Tier REMIC for purposes of the
      REMIC Provisions. In addition, each Certificate, other than the Class R, Class
      LT-R, Class X and Class P Certificates, represents (i) the right to receive
      payments with respect to any Basis Risk Shortfalls and Unpaid Basis Risk
      Shortfalls and (ii) the obligation to pay Class I Shortfalls. The Class LT-R
      Certificate represents ownership of the sole Class of residual interest in
      REMIC 1. The Class R Certificate represents ownership of the sole Class of
      residual interest in each of REMIC 2, REMIC 3 and the Upper Tier REMIC for
      purposes of the REMIC Provisions.

     

    The
      Upper
      Tier REMIC shall hold as its assets the uncertificated Lower Tier Interests
      in
      REMIC 3, other than the Class LT3-R interest, and each such Lower Tier
      Interest is hereby designated as a regular interest in REMIC 3. REMIC 3
      shall hold as its assets the uncertificated Lower Tier Interests in REMIC 2,
      other than the Class LT2-R interest, and each such Lower Tier Interest is hereby
      designated as a regular interest in REMIC 2. REMIC 2 shall hold as its assets
      the uncertificated Lower Tier Interests in REMIC 1 and each such Lower Tier
      Interest is hereby designated as a regular interest in REMIC 1. REMIC 1 shall
      hold as its assets the property of the Trust Fund other than the Lower Tier
      Interests in REMIC 1, REMIC 2, REMIC 3 and the Upper Tier REMIC
      and the Excluded Trust Assets.

     

    
      
        
        

      

      
        1

        
          

        

      

      
        
        

      

    

     

    The
      startup day for each REMIC created hereby for purposes of the REMIC Provisions
      is the Closing Date. In addition, for purposes of the REMIC Provisions, the
      latest possible maturity date for each regular interest in each REMIC created
      hereby is the Latest Possible Maturity Date.

     

    REMIC
      1:

     

    REMIC
      1
      shall issue one uncertificated interest in respect of each Mortgage Loan held
      by
      the Trust Fund on the Closing Date, each of which is hereby designated as a
      regular interest in REMIC 1 (the “REMIC 1 Regular Interests”). REMIC 1 shall
      also issue the Class LT-R Certificate, which shall represent the sole class
      of
      residual interest in REMIC 1. Each REMIC 1 Regular Interest shall have an
      initial principal balance equal to the Scheduled Principal Balance of the
      Mortgage Loan to which it relates and shall bear interest at a per annum rate
      equal to the Net Mortgage Rate of such Mortgage Loan. In the event a Qualifying
      Substitute Mortgage Loan is substituted for such Mortgage Loan (the “Original
      Mortgage Loan”), no amount of interest payable on such Qualifying Substitute
      Mortgage Loan shall be distributed on such REMIC 1 Regular Interest at a rate
      in
      excess of the Net Mortgage Rate of the Original Mortgage Loan.

     

    On
      each
      Distribution Date, the Trustee shall first pay or charge as an expense of REMIC
      1 all expenses of the Trust Fund for such Distribution Date, other than any
      expenses in respect of the Swap Agreement.

     

    On
      each
      Distribution Date the Trustee shall distribute the aggregate Interest Remittance
      Amount (net of expenses described in the preceding paragraph) with respect
      to
      each of the Lower Tier Interests in REMIC 1 based on the above-described
      interest rates.

     

    On
      each
      Distribution Date, the Trustee shall distribute the aggregate Principal
      Remittance Amount among the Lower Tier Interests in REMIC 1 in accordance with
      the amount of the Principal Remittance Amount attributable to the Mortgage
      Loan
      corresponding to each such Lower Tier Interest in REMIC 1. All losses on the
      Mortgage Loans shall be allocated among the Lower Tier Interests in REMIC 1
      in
      the same manner that principal distributions are allocated.

     

    On
      each
      Distribution Date, the Trustee shall distribute the Prepayment Premiums
      collected during the preceding Prepayment Period, in the case of Principal
      Prepayments in full, or during the related Collection Period, in the case of
      Principal Prepayments in part, to the Lower Tier Interest in REMIC 1
      corresponding to the Mortgage Loan with respect to which such amounts were
      received.

     

    
      
        
        

      

      
        2

        
          

        

      

      
        
        

      

    

     

    REMIC
      2:

     

    The
      following table sets forth the designations, principal balances and interest
      rates for each interest in REMIC 2, each of which (other than the Class LT2-R
      Lower Tier Interest) is hereby designated as a regular interest in REMIC 2
      (the
“REMIC 2 Regular Interests”):

     

    
      	
              Class
                Designation

            	 	
              Initial
                Class Principal Amount

            	 	
               

              Interest
                Rate

            	 
	
              LT2-A

            	 	 	
              31,734,697.32

            	 	 	
              (1

            	
              )

            
	
              LT2-F1

            	 	 	
              5,891,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V1

            	 	 	
              5,891,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F2

            	 	 	
              8,297,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V2

            	 	 	
              8,297,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F3

            	 	 	
              8,491,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V3

            	 	 	
              8,491,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F4

            	 	 	
              8,190,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V4

            	 	 	
              8,190,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F5

            	 	 	
              7,899,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V5

            	 	 	
              7,899,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F6

            	 	 	
              7,619,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V6

            	 	 	
              7,619,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F7

            	 	 	
              7,348,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V7

            	 	 	
              7,348,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F8

            	 	 	
              7,086,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V8

            	 	 	
              7,086,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F9

            	 	 	
              8,064,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V9

            	 	 	
              8,064,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F10

            	 	 	
              7,725,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V10

            	 	 	
              7,725,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F11

            	 	 	
              8,078,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V11

            	 	 	
              8,078,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F12

            	 	 	
              9,487,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V12

            	 	 	
              9,487,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F13

            	 	 	
              8,952,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V13

            	 	 	
              8,952,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F14

            	 	 	
              8,446,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V14

            	 	 	
              8,446,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F15

            	 	 	
              7,969,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V15

            	 	 	
              7,969,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F16

            	 	 	
              7,520,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V16

            	 	 	
              7,520,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F17

            	 	 	
              7,095,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V17

            	 	 	
              7,095,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F18

            	 	 	
              6,695,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V18

            	 	 	
              6,695,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F19

            	 	 	
              6,316,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V19

            	 	 	
              6,316,500.00

            	 	 	
              (3

            	
              )

            


    

     

    
      
        
        

      

      
        3

        
          

        

      

      
        
        

      

    

     

    
      	
              Class
                Designation

            	 	 	
              Initial
                Class Principal Amount

            	 	 	
              Interest
                Rate

            	 
	
              LT2-F20

            	 	 	
              5,960,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V20

            	 	 	
              5,960,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F21

            	 	 	
              17,400,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V21

            	 	 	
              17,400,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F22

            	 	 	
              12,029,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V22

            	 	 	
              12,029,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F23

            	 	 	
              8,816,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V23

            	 	 	
              8,816,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F24

            	 	 	
              6,702,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V24

            	 	 	
              6,702,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F25

            	 	 	
              5,225,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V25

            	 	 	
              5,225,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F26

            	 	 	
              4,149,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V26

            	 	 	
              4,149,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F27

            	 	 	
              3,337,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V27

            	 	 	
              3,337,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F28

            	 	 	
              2,709,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V28

            	 	 	
              2,709,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F29

            	 	 	
              2,533,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V29

            	 	 	
              2,533,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F30

            	 	 	
              2,369,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V30

            	 	 	
              2,369,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F31

            	 	 	
              2,215,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V31

            	 	 	
              2,215,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F32

            	 	 	
              2,072,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V32

            	 	 	
              2,072,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F33

            	 	 	
              1,938,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V33

            	 	 	
              1,938,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F34

            	 	 	
              1,813,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V34

            	 	 	
              1,813,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F35

            	 	 	
              1,695,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V35

            	 	 	
              1,695,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F36

            	 	 	
              1,585,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V36

            	 	 	
              1,585,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F37

            	 	 	
              1,482,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V37

            	 	 	
              1,482,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F38

            	 	 	
              1,387,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V38

            	 	 	
              1,387,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F39

            	 	 	
              1,296,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V39

            	 	 	
              1,296,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F40

            	 	 	
              1,212,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V40

            	 	 	
              1,212,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F41

            	 	 	
              1,134,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V41

            	 	 	
              1,134,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F42

            	 	 	
              1,060,500.00

            	 	 	
              (2

            	
              )

            


    

     

    
      
        
        

      

      
        4

        
          

        

      

      
        
        

      

    

     

    
      	
              Class
                Designation

            	 	 	
              Initial
                Class Principal Amount

            	 	 	
              Interest
                Rate

            	 
	
              LT2-V42

            	 	 	
              1,060,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F43

            	 	 	
              992,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V43

            	 	 	
              992,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F44

            	 	 	
              928,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V44

            	 	 	
              928,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F45

            	 	 	
              867,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V45

            	 	 	
              867,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F46

            	 	 	
              811,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V46

            	 	 	
              811,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F47

            	 	 	
              758,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V47

            	 	 	
              758,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F48

            	 	 	
              709,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V48

            	 	 	
              709,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F49

            	 	 	
              663,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V49

            	 	 	
              663,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F50

            	 	 	
              620,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V50

            	 	 	
              620,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F51

            	 	 	
              580,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V51

            	 	 	
              580,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F52

            	 	 	
              542,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V52

            	 	 	
              542,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F53

            	 	 	
              507,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V53

            	 	 	
              507,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F54

            	 	 	
              474,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V54

            	 	 	
              474,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F55

            	 	 	
              443,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V55

            	 	 	
              443,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F56

            	 	 	
              415,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V56

            	 	 	
              415,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F57

            	 	 	
              388,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V57

            	 	 	
              388,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F58

            	 	 	
              363,000.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V58

            	 	 	
              363,000.00

            	 	 	
              (3

            	
              )

            
	
              LT2-F59

            	 	 	
              2,562,500.00

            	 	 	
              (2

            	
              )

            
	
              LT2-V59

            	 	 	
              2,562,500.00

            	 	 	
              (3

            	
              )

            
	
              LT2-R

            	 	 	
              (4

            	
              )

            	 	
              (4

            	
              )

            


    

     

     

      
        

      

    

    
      	(1)  	
              For
                any Distribution Date (and the related Accrual Period) the interest
                rate
                for the Class LT2-A Interest shall be the Net WAC Rate.
                

            


    

     

    
      	(2)  	
              For
                any Distribution Date (and the related Accrual Period) the interest
                rate
                for each of these REMIC 2 Regular Interests shall be the lesser of
                (i) the
                REMIC Swap Rate for such Distribution Date, and (ii) the product
                of (a)
                the Net WAC Rate and (b) 2.

            


    

     

    
      
        
        

      

      
        5

        
          

        

      

      
        
        

      

    

     

    
      	(3)  	
              For
                any Distribution Date (and the related Accrual Period) the interest
                rate
                for each of these REMIC 2 Regular Interests shall be the excess,
                if any,
                of (i) the product of (a) the Net WAC Rate and (b) 2, over (ii) the
                REMIC
                Swap Rate for such Distribution Date and, if no such excess, shall
                be
                zero.

            


    

     

    
      	(4)  	
              The
                Class LT2-R interest shall not have a principal amount and shall
                not bear
                interest. The Class LT2-R interest is hereby designated as the sole
                class
                of residual interest in REMIC 2.

            


    

     

    On
      each
      Distribution Date, the Trustee shall distribute the aggregate Interest
      Remittance Amount with respect to each of the REMIC 2 Regular Interests based
      on
      the above-described interest rates.

     

    On
      each
      Distribution Date, the Trustee shall distribute the Principal Remittance Amount
      with respect to the REMIC 2 Regular Interests, first to the Class LT2-A Interest
      until its Class Principal Amount is reduced to zero, and then sequentially,
      to
      the other REMIC 2 Regular Interests in ascending order of their numerical class
      designation, and, with respect to each pair of classes having the same numerical
      designation, in equal amounts to each such class, until the Class Principal
      Amount of each such class is reduced to zero. All losses on the Mortgage Loans
      shall be allocated among the REMIC 2 Regular Interests in the same manner that
      principal distributions are allocated.

     

    On
      each
      Distribution Date, the Trustee shall distribute the Prepayment Premiums for
      prepayments in part and prepayments in full collected during the applicable
      Prepayment Period to the Class LT2-F59 and Class LT2-V59 Interests,
      respectively.

     

    REMIC
      3:

     

    The
      following table sets forth the designations, principal balances and interest
      rates for each interest in REMIC 3, each of which (other than the Class LT3-R
      interest) is hereby designated as a regular interest in REMIC 3 (the “REMIC 3
      Regular Interests”):

     

    
      	
              REMIC
                3

              Lower
                Tier 

              Class
                Designation

            	 	
              REMIC
                3

              Lower
                Tier

              Interest
                Rate

            	 	
              Initial
                Class 

              Principal
                Amount

            	 	
              Corresponding
                Class of Certificate(s)

            
	
              Class
                LT3-A

            	 	
              (1)

            	 	
              (2)

            	 	
              A

            
	
              Class
                LT3-M1

            	 	
              (1)

            	 	
              (2)

            	 	
              M1

            
	
              Class
                LT3-M2

            	 	
              (1)

            	 	
              (2)

            	 	
              M2

            
	
              Class
                LT3-M3

            	 	
              (1)

            	 	
              (2)

            	 	
              M3

            
	
              Class
                LT3-M4

            	 	
              (1)

            	 	
              (2)

            	 	
              M4

            
	
              Class
                LT3-M5

            	 	
              (1)

            	 	
              (2)

            	 	
              M5

            
	
              Class
                LT3-M6

            	 	
              (1)

            	 	
              (2)

            	 	
              M6

            
	
              Class
                LT3-M7

            	 	
              (1)

            	 	
              (2)

            	 	
              M7

            
	
              Class
                LT3-M8

            	 	
              (1)

            	 	
              (2)

            	 	
              M8

            
	
              Class
                LT3-M9

            	 	
              (1)

            	 	
              (2)

            	 	
              M9

            
	
              Class
                LT3-B1

            	 	
              (1)

            	 	
              (2)

            	 	
              B1

            
	
              Class
                LT3-B2

            	 	
              (1)

            	 	
              (2)

            	 	
              B2

            
	
              Class
                LT3-Q

            	 	
              (1)

            	 	
              (3)

            	 	
              N/A

            
	
              Class
                LT3-SIO

            	 	
              (4)

            	 	
              (4)

            	 	
              N/A

            
	
              Class
                LT3-R

            	 	
              (5)

            	 	
              (5)

            	 	
              R

            


    

     

    
      
        
        

      

      
        6

        
          

        

      

      
        
        

      

    

     

      
        

      

    

    
      	 	
              (1)

            	
              For
                any Distribution Date (and the related Accrual Period) the interest
                rate
                for each of these REMIC 3 Interests is a per annum rate equal to
                the
                weighted average of the interest rates on the Lower Tier Interests
                in
                REMIC 2 for such Distribution Date, provided,
                however, that
                for any Distribution Date on which the Class LT3-SIO Interest is
                entitled
                to a portion of the interest accruals on a Lower Tier Interest in
                REMIC 2
                having an “F” in its class designation, as described in footnote (2)
                below, such weighted average shall be computed by first subjecting
                the
                rate on such Lower Tier Interest in REMIC 2 to a cap equal to Swap
                LIBOR
                for such Distribution Date.

            


    

     

    
      	
            	(2)	
              This
                interest shall have an initial class principal amount equal to one-half
                of
                the initial Class Principal Amount of its Corresponding Class of
                Certificates.

            


    

     

    
      	
            	(3)	
              This
                interest shall have an initial principal balance equal to the excess
                of
                (a) the aggregate Principal Balance of the REMIC 2 Interests as of
                the Cut-off Date over (b) the sum of the initial principal balances
                of the
                interests in REMIC 3.

            


    

     

    
      	 	
              (4)

            	
              The
                Class LT3-SIO is an interest only class that does not have a principal
                balance. For only those Distribution Dates listed in the first column
                in
                the table below, the Class LT3-SIO shall be entitled to interest
                accrued
                on the Lower Tier Interest in REMIC 2 listed in the second column
                in the
                table below at a per annum rate equal to the excess, if any, of (i)
                the
                interest rate for such Lower Tier Interest in REMIC 2 for such
                Distribution Date over (ii) Swap LIBOR for such Distribution
                Date.

            


    

     

    
      	
              Distribution
                Dates

            	 	
              REMIC
                2
                Class Designation

            
	
              2

            	 	
              Class
                LT2-F1

            
	
              2-3

            	 	
              Class
                LT2-F2

            
	
              2-4

            	 	
              Class
                LT2-F3

            
	
              2-5

            	 	
              Class
                LT2-F4

            
	
              2-6

            	 	
              Class
                LT2-F5

            
	
              2-7

            	 	
              Class
                LT2-F6

            
	
              2-8

            	 	
              Class
                LT2-F7

            
	
              2-9

            	 	
              Class
                LT2-F8

            
	
              2-10

            	 	
              Class
                LT2-F9

            
	
              2-11

            	 	
              Class
                LT2-F10

            
	
              2-12

            	 	
              Class
                LT2-F11

            
	
              2-13

            	 	
              Class
                LT2-F12

            
	
              2-14

            	 	
              Class
                LT2-F13

            
	
              2-15

            	 	
              Class
                LT2-F14

            
	
              2-16

            	 	
              Class
                LT2-F15

            
	
              2-17

            	 	
              Class
                LT2-F16

            
	
              2-18

            	 	
              Class
                LT2-F17

            
	
              2-19

            	 	
              Class
                LT2-F18

            
	
              2-20

            	 	
              Class
                LT2-F19

            
	
              2-21

            	 	
              Class
                LT2-F20

            
	
              2-22

            	 	
              Class
                LT2-F21

            
	
              2-23

            	 	
              Class
                LT2-F22

            
	
              2-24

            	 	
              Class
                LT2-F23

            
	
              2-25

            	 	
              Class
                LT2-F24

            
	
              2-26

            	 	
              Class
                LT2-F25

            
	
              2-27

            	 	
              Class
                LT2-F26

            
	
              2-28

            	 	
              Class
                LT2-F27

            
	
              2-29

            	 	
              Class
                LT2-F28

            
	
              2-30

            	 	
              Class
                LT2-F29

            
	
              2-31

            	 	
              Class
                LT2-F30

            
	
              2-32

            	 	
              Class
                LT2-F31

            
	
              2-33

            	 	
              Class
                LT2-F32

            
	
              2-34

            	 	
              Class
                LT2-F33

            


    

     

    
      
        
        

      

      
        7

        
          

        

      

      
        
        

      

    

     

    
      	
              2-35

            	 	
              Class
                LT2-F34

            
	
              2-36

            	 	
              Class
                LT2-F35

            
	
              2-37

            	 	
              Class
                LT2-F36

            
	
              2-38

            	 	
              Class
                LT2-F37

            
	
              2-39

            	 	
              Class
                LT2-F38

            
	
              2-40

            	 	
              Class
                LT2-F39

            
	
              2-41

            	 	
              Class
                LT2-F40

            
	
              2-42

            	 	
              Class
                LT2-F41

            
	
              2-43

            	 	
              Class
                LT2-F42

            
	
              2-44

            	 	
              Class
                LT2-F43

            
	
              2-45

            	 	
              Class
                LT2-F44

            
	
              2-46

            	 	
              Class
                LT2-F45

            
	
              2-47

            	 	
              Class
                LT2-F46

            
	
              2-48

            	 	
              Class
                LT2-F47

            
	
              2-49

            	 	
              Class
                LT2-F48

            
	
              2-50

            	 	
              Class
                LT2-F49

            
	
              2-51

            	 	
              Class
                LT2-F50

            
	
              2-52

            	 	
              Class
                LT2-F51

            
	
              2-53

            	 	
              Class
                LT2-F52

            
	
              2-54

            	 	
              Class
                LT2-F53

            
	
              2-55

            	 	
              Class
                LT2-F54

            
	
              2-56

            	 	
              Class
                LT2-F55

            
	
              2-57

            	 	
              Class
                LT2-F56

            
	
              2-58

            	 	
              Class
                LT2-F57

            
	
              2-59

            	 	
              Class
                LT2-F58

            
	
              2-60

            	 	
              Class
                LT2-F59

            


    

    


    
      	 	
              (5)

            	
              The
                Class LT3-R interest is the sole class of residual interests in REMIC
                3.
                It does not have an interest rate or a principal
                balance.

            


    

     

    On
      each
      Distribution Date, interest distributable in respect of the REMIC 2 Regular
      Interests shall be distributed with respect to each of the REMIC 3 Regular
      Interests based on the above-described interest rates, provided, however,
      that
      interest that accrues on the LT3-Q Interest shall be deferred to the extent
      necessary to make the principal distributions described in priority (i) below
      for such Distribution Date. Any interest so deferred shall itself bear interest
      at the interest rate for the LT3-Q Interest.

     

    On
      each
      Distribution Date, the principal distributed on the REMIC 2 Regular Interests
      (together with an amount equal to the interest deferred on the Class LT3-Q
      Interest for such Distribution Date) shall be distributed, and Realized Losses
      shall be allocated, among the REMIC 3 Regular Interests in the following order
      of priority:

     

    (i) first,
      to
      each
      REMIC 3 Regular Interest having a Corresponding Class in REMIC 4 until the
      Class Principal Amount of each such REMIC 3 Regular Interest equals
      one-half of the Class Principal Amount of the Corresponding Class of
      Certificates immediately after such Distribution Date;

     

    (ii) second,
      to the Class LT3-Q Interest, any remaining amounts.

     

    On
      each
      Distribution Date, the Trustee shall distribute the Prepayment Premiums
      collected during the preceding Prepayment Period to the LT3-Q
      Interest.

     

    
      
        
        

      

      
        8

        
          

        

      

      
        
        

      

    

     

    The
      Certificates - REMIC 4

     

    The
      following table sets forth (or describes) the Class designation, Certificate
      Interest Rate, initial Class Principal Amount and minimum denomination for
      each
      Class of Certificates comprising interests in the Trust Fund created hereunder.
      Each Certificate, other than the Class R and Class LT-R Certificates represents
      ownership of regular interests in REMIC 4. 

     

    
      	
              Class
Designation

            	 	
              Certificate
Interest
                Rate

            	 	
               

              Initial
                Class

              Principal
                Amount ($)

            	 	
              Minimum
Denomination
                or
Percentage Interest

            
	
              Class
                A

            	 	
              (1)

            	 	
              367,586,000.00

            	 	
              $
                25,000.00

            
	
              Class
                M1

            	 	
              (2)

            	 	
              30,566,000.00

            	 	
              $100,000.00

            
	
              Class
                M2

            	 	
              (3)

            	 	
              27,643,000.00

            	 	
              $100,000.00

            
	
              Class
                M3

            	 	
              (4)

            	 	
              11,695,000.00

            	 	
              $100,000.00

            
	
              Class
                M4

            	 	
              (5)

            	 	
              13,821,000.00

            	 	
              $100,000.00

            
	
              Class
                M5

            	 	
              (6)

            	 	
              9,569,000.00

            	 	
              $100,000.00

            
	
              Class
                M6

            	 	
              (7)

            	 	
              7,974,000.00

            	 	
              $100,000.00

            
	
              Class
                M7

            	 	
              (8)

            	 	
              9,834,000.00

            	 	
              $100,000.00

            
	
              Class
                M8

            	 	
              (9)

            	 	
              7,177,000.00

            	 	
              $100,000.00

            
	
              Class
                M9

            	 	
              (10)

            	 	
              7,442,000.00

            	 	
              $100,000.00

            
	
              Class
                B1

            	 	
              (11)

            	 	
              18,074,000.00

            	 	
              $100,000.00

            
	
              Class
                B2

            	 	
              (12)

            	 	
              16,214,000.00

            	 	
              $100,000.00

            
	
              Class
                P

            	 	
              (13)

            	 	
              (13)

            	 	
              (16)

            
	
              Class
                X

            	 	
              (14)

            	 	
              (14)

            	 	
              (16)

            
	
              Class
                R

            	 	
              (15)

            	 	
              (15)

            	 	
              (16)

            
	
              Class
                LT-R

            	 	
              (17)

            	 	
              (17)

            	 	
              (17)

            


    

     

      
        

      

    

    
      	(1)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class A Certificates is the per annum
                rate
                equal to the lesser of (i) LIBOR plus
                0.170%
                and (ii) the Net Funds Cap for such Distribution Date;
                provided
                that if the Mortgage Loans and related property are not purchased
                pursuant
                to Section 7.01(b) on the Initial Optional Termination Date, then
                with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class A Certificates
                will
                be LIBOR plus
                0.340%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class A Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof.

            


    

     

    
      	(2)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class M1 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                0.400% and (ii) the Net Funds Cap for such Distribution Date;
                provided
                that if the Mortgage Loans and related property are not purchased
                pursuant
                to Section 7.01(b) on the Initial Optional Termination Date, then
                with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class M1 Certificates
                will be LIBOR plus
                0.600%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class M1 Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof. 

            


    

     

    
      
        
        

      

      
        9

        
          

        

      

      
        
        

      

    

     

    
      	(3)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class M2 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                0.430% and (ii) the Net Funds Cap for such Distribution Date;
                provided
                that if the Mortgage Loans and related property are not purchased
                pursuant
                to Section 7.01(b) on the Initial Optional Termination Date, then
                with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class M2 Certificates
                will be LIBOR plus
                0.645%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class M2 Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof.

            


    

     

    
      	(4)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class M3 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                0.500% and (ii) the Net Funds Cap for such Distribution Date;
                provided
                that if the Mortgage Loans and related property are not purchased
                pursuant
                to Section 7.01(b) on the Initial Optional Termination Date, then
                with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class M3 Certificates
                will be LIBOR plus
                0.750%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class M3 Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof.

            


    

     

    
      	(5)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class M4 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                0.550% and (ii) the Net Funds Cap for such Distribution Date;
                provided
                that if the Mortgage Loans and related property are not purchased
                pursuant
                to Section 7.01(b) on the Initial Optional Termination Date, then
                with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class M4 Certificates
                will be LIBOR plus
                0.825%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class M4 Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof.

            


    

     

    
      	(6)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class M5 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                0.650% and (ii) the Net Funds Cap for such Distribution Date;
                provided that
                if the Mortgage Loans and related property are not purchased pursuant
                to
                Section 7.01(b) on the Initial Optional Termination Date, then with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class M5 Certificates
                will be LIBOR plus
                0.975%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class M5 Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof.

            


    

     

    
      
        
        

      

      
        10

        
          

        

      

      
        
        

      

    

     

    
      	(7)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class M6 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                0.750% and (ii) the Net Funds Cap for such Distribution Date;
                provided that
                if the Mortgage Loans and related property are not purchased pursuant
                to
                Section 7.01(b) on the Initial Optional Termination Date, then with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class M6 Certificates
                will be LIBOR plus
                1.125%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class M6 Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof.

            


    

     

    
      	(8)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class M7 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                1.600% and (ii) the Net Funds Cap for such Distribution Date;
                provided that
                if the Mortgage Loans and related property are not purchased pursuant
                to
                Section 7.01(b) on the Initial Optional Termination Date, then with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class M7 Certificates
                will be LIBOR plus
                2.400%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class M7 Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof.

            


    

     

    
      	(9)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class M8 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                2.500% and (ii) the Net Funds Cap for such Distribution Date;
                provided that
                if the Mortgage Loans and related property are not purchased pursuant
                to
                Section 7.01(b) on the Initial Optional Termination Date, then with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class M8 Certificates
                will be LIBOR plus
                3.750%.
                For purposes of the REMIC Provisions, the reference to “Net Funds Cap” in
                clause (ii) of the preceding sentence shall be deemed to be a reference
                to
                the REMIC 3 Net Funds Cap. For any Distribution Date on which the
                Certificate Interest Rate for this Certificate is based on the Net
                Funds
                Cap, the amount of interest that would have payable on such Certificates
                if the REMIC 3 Net Funds Cap were substituted for the Net Funds Cap
                over the amount actually payable thereon shall be treated as having
                been
                paid to the owners of the Class M8 Certificates and then deposited
                by such
                owners into the Supplemental Interest Trust pursuant to Section 10.01(n)
                hereof.

            


    

     

    
      	(10)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class M9 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                2.750% and (ii) the Net Funds Cap for such Distribution Date;
                provided that
                if the Mortgage Loans and related property are not purchased pursuant
                to
                Section 7.01(b) on the Initial Optional Termination Date, then with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class M9 Certificates
                will be LIBOR plus
                4.125%.
                For purposes of the REMIC Provisions, the reference to “Net Funds Cap” in
                clause (ii) of the preceding sentence shall be deemed to be a reference
                to
                the REMIC 3 Net Funds Cap. For any Distribution Date on which the
                Certificate Interest Rate for this Certificate is based on the Net
                Funds
                Cap, the amount of interest that would have payable on such Certificates
                if the REMIC 3 Net Funds Cap were substituted for the Net Funds Cap
                over the amount actually payable thereon shall be treated as having
                been
                paid to the owners of the Class M9 Certificates and then deposited
                by such
                owners into the Supplemental Interest Trust pursuant to Section 10.01(n)
                hereof.

            


    

     

    
      	(11)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class B1 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                2.750% and (ii) the Net Funds Cap for such Distribution Date;
                provided that
                if the Mortgage Loans and related property are not purchased pursuant
                to
                Section 7.01(b) on the Initial Optional Termination Date, then with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class B1 Certificates
                will be LIBOR plus
                4.125%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class B1 Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof.

            


    

     

    
      
        
        

      

      
        11

        
          

        

      

      
        
        

      

    

     

    
      	(12)  	
              The
                Certificate Interest Rate with respect to any Distribution Date (and
                the
                related Accrual Period) for the Class B2 Certificates is the per
                annum
                rate equal to the lesser of (i) LIBOR plus
                2.750% and (ii) the Net Funds Cap for such Distribution Date;
                provided that
                if the Mortgage Loans and related property are not purchased pursuant
                to
                Section 7.01(b) on the Initial Optional Termination Date, then with
                respect to each subsequent Distribution Date the per annum rate calculated
                pursuant to clause (i) above with respect to the Class B2 Certificates
                will be LIBOR plus
                4.125%. For purposes of the REMIC Provisions, the reference to “Net Funds
                Cap” in clause (ii) of the preceding sentence shall be deemed to be a
                reference to the REMIC 3 Net Funds Cap. For any Distribution Date on
                which the Certificate Interest Rate for this Certificate is based
                on the
                Net Funds Cap, the amount of interest that would have payable on
                such
                Certificates if the REMIC 3 Net Funds Cap were substituted for the
                Net Funds Cap over the amount actually payable thereon shall be treated
                as
                having been paid to the owners of the Class B2 Certificates and then
                deposited by such owners into the Supplemental Interest Trust pursuant
                to
                Section 10.01(n) hereof.

            


    

     

    
      	(13)  	
              The
                Class P Certificates will not bear interest at a stated rate. The
                Class P
                Certificates shall have a Class P Principal Amount equal to $100
                and shall
                be entitled to receive all Prepayment Premiums paid with respect
                to the
                Mortgage Loans for which the Seller is entitled to such payment as
                provided in Section 5.02(g). 

            


    

     

    
      	(14)  	
              The
                Class X Certificates shall have an initial principal balance of
                $3,986,597.32 (initial overcollateralization of $3,986,697.32 minus
                $100.00 allocated to the Class P Certificates), but shall not accrue
                interest on that balance. In addition to the right to receive ultimately
                the initial principal balance, which right represents a regular interest
                in the Upper-Tier REMIC, the Class X Certificate shall also comprise
                2
                notional components, each of which represents a regular interest
                in the
                Upper-Tier REMIC. The first such component has a notional balance
                that
                will at all times equal the aggregate of the principal balances of
                the
                regular interests in REMIC 3 (i.e. the Pool Balance), and, for each
                Distribution Date (and the related Accrual Period) this notional
                component
                shall bear interest at a per annum rate equal to the excess, if any,
                of
                (i) the excess of (a) the weighted average of the interest rates
                on the
                regular interests in REMIC 3 (other than any interest-only regular
                interest) over (b) the Credit Risk Manager’s Fee Rate, over (ii) the
                Adjusted Lower-Tier WAC. The second notional component represents
                the
                right to receive all distributions in respect of the Class LT3-SIO
                Interest in REMIC 3 (the “Class I” interest). In addition, for
                purposes of the REMIC Provisions, the Class X Certificate shall represent
                beneficial ownership of (i) the Basis Risk Reserve Fund; (ii) the
                Supplemental Interest Trust, including the Swap Agreement and the
                Swap
                Account and (iii) an interest in the notional principal contracts
                described in Section 10.01(n)
                hereof.

            


    

     

    
      	(15)  	
              The
                Class R Certificates will be issued without a Certificate Principal
                Amount
                and will not bear interest at a stated rate. The Class R Certificates
                represent ownership of the residual interest in the Upper Tier REMIC,
                as
                well as ownership of the Class LT2-R
                Interest.

            


    

     

    
      	(16)  	
              The
                Class X Certificates and Class P Certificates will each be issued
                in
                minimum Percentage Interests of 10%. The Class R Certificates will
                be
                issued as a single Certificate evidencing the entire Percentage Interest
                in such Class.

            


    

     

    
      	(17)  	
              The
                Class LT-R Certificate will be issued without a Class Principal Amount
                and
                will not bear interest at a stated rate. The Class LT-R Certificate
                represents ownership of the residual interest in REMIC 1. The Class
                LT-R
                Certificate will be issued as a single Certificate evidencing the
                entire
                Percentage Interest in such Class.

            


    

     

    
      
        
        

      

      
        12

        
          

        

      

      
        
        

      

    

     

    As
      of the
      Cut-off Date, the Mortgage Loans had an aggregate Scheduled Principal Balance
      of
$531,581,697.32.

     

    In
      consideration of the mutual agreements herein contained, the Depositor, the
      Seller, the Credit Risk Manager, the Master Servicer and the Trustee hereby
      agree as follows:

     

    ARTICLE
      I

     

    DEFINITIONS

    


    
      	 	
              Section
                1.01 

            	
              Definitions. The
                following words and phrases, unless the context otherwise requires,
                shall
                have the following meanings:

            


    

     

    10-K
      Filing Deadline:
      As
      defined in Section 6.20(e)(i).

     

    Accepted
      Servicing Practices:
      With
      respect to any Mortgage Loan, as applicable, either (x) those customary mortgage
      servicing practices of prudent mortgage servicing institutions that service
      or
      master service mortgage loans of the same type and quality as such Mortgage
      Loan
      in the jurisdiction where the related Mortgaged Property is located, to the
      extent applicable to the Trustee (as successor Master Servicer) or the Master
      Servicer or (y) as provided in the Servicing Agreement, to the extent applicable
      to the Servicer.

     

    Accountant:
      A
      person engaged in the practice of accounting who (except when this Agreement
      provides that an Accountant must be Independent) may be employed by or
      affiliated with the Depositor or an Affiliate of the Depositor.

     

    Accrual
      Period:
      With
      respect to any Distribution Date and each Class of LIBOR Certificates, the
      period beginning on the Distribution Date in the calendar month immediately
      preceding the month in which the related Distribution Date occurs (or on
      December 25, 2006, in the case of the first Accrual Period) and ending on
      the day immediately preceding the related Distribution Date. 

     

    Additional
      Collateral:
      None.

     

    Additional
      Form 10-D Disclosure:
      As
      defined in Section 6.20(d)(i).

     

    Additional
      Form 10-K Disclosure:
      As
      defined in Section 6.20(e)(i).

     

    Additional
      Servicer:
      Each
      affiliate of the Servicer that Services any of the Mortgage Loans and each
      Person who is not an affiliate of the Servicer who Services 10% or more of
      the
      Mortgage Loans.

     

    Additional
      Termination Event:
      As
      defined in the Swap Agreement.

     

    Adjusted
      Lower Tier WAC:
      For any
      Distribution Date (and the related Accrual Period) the product of (i) 2, and
      (ii) the weighted average of the interest rates on the Lower Tier Interests
      in
      REMIC 3 (other than any interest-only interest), weighted in proportion to
      their Class Principal Amounts as of the beginning of the related Accrual Period
      and determined for this purpose by first subjecting the rate at which interest
      accrues on the Class LT3-Q Interest to a cap of zero, and subjecting the rate
      at
      which interest accrues on each remaining REMIC 3 Regular Interest to a cap
      that corresponds to the Certificate Interest Rate for its Corresponding Class
      of
      Certificates for such Distribution Date (adjusted to reflect the day count
      convention used to compute the amount of interest accruals for such
      Corresponding Class).

     

    
      
        
        

      

      
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    Advance:
      An
      advance of the aggregate of payments (other than Balloon Payments) of principal
      and interest (net of the Servicing Fee) on one or more Mortgage Loans (other
      than Charged-off Loans or Released Mortgage Loans) that were due on the Due
      Date
      in the related Collection Period and not received as of the close of business
      on
      the related Determination Date, required to be made by the Servicer or by the
      Master Servicer on behalf of the Servicer (or by the Trustee as successor Master
      Servicer) pursuant to Section 5.04.

     

    Adverse
      REMIC Event:
      Either
      (i) the loss of status as a REMIC, within the meaning of Section 860D of the
      Code, for any group of assets identified as a REMIC in the Preliminary Statement
      to this Agreement, or (ii) the imposition of any tax, including the tax imposed
      under Section 860F(a)(1) of the Code on prohibited transactions, and the tax
      imposed under Section 860G(d) of the Code on certain contributions to a REMIC,
      on any REMIC created hereunder to the extent such tax would be payable from
      assets held as part of the Trust Fund.

     

    Affected
      Party:
      As
      defined in the Swap Agreement.

     

    Affiliate:
      With
      respect to any specified Person, any other Person controlling or controlled
      by
      or under common control with such specified Person. For the purposes of this
      definition, “control” when used with respect to any specified Person means the
      power to direct the management and policies of such Person, directly or
      indirectly, whether through the ownership of voting securities, by contract
      or
      otherwise; and the terms “controlling” and “controlled” have meanings
      correlative to the foregoing.

     

    Aggregate
      Overcollateralization Release Amount:
      With
      respect to any Distribution Date, the lesser of (x) the Principal Remittance
      Amount for such Distribution Date and (y) the amount, if any, by which (i)
      the
      Overcollateralization Amount for such Distribution Date (calculated for this
      purpose on the basis of the assumption that 100% of the Principal Remittance
      Amount for such date is applied on such date in reduction of the aggregate
      Certificate Principal Amount of the Certificates) exceeds (ii) the Enhancement
      Target for such Distribution Date.

     

    Aggregate
      Voting Interests:
      The
      aggregate of the Voting Interests of all the Certificates under this
      Agreement.

     

    Agreement:
      This
      Trust Agreement and all amendments and supplements hereto.

     

    Anniversary
      Year:
      The
      one-year period beginning on the Closing Date and ending on the first
      anniversary thereof, and each subsequent one-year period beginning on the day
      after the end of the preceding Anniversary Year and ending on the next
      succeeding anniversary of the Closing Date.

     

    Applied
      Loss Amount:
      With
      respect to any Distribution Date, the amount, if any, by which (x) the aggregate
      Class Principal Amount of the Certificates after giving effect to all Realized
      Losses incurred with respect to the Mortgage Loans during the related Collection
      Period and distributions of principal on such Distribution Date, but before
      giving effect to any application of the Applied Loss Amount with respect to
      such
      date, exceeds (y) the Pool Balance for such Distribution Date.

     

    
      
        
        

      

      
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    Appraised
      Value:
      With
      respect to any Mortgage Loan, the amount set forth in an appraisal made in
      connection with the origination of such Mortgage Loan as the value of the
      related Mortgaged Property.

     

    Assignment
      of Mortgage:
      An
      assignment of the Mortgage, notice of transfer or equivalent instrument, in
      recordable form, sufficient under the laws of the jurisdiction wherein the
      related Mortgaged Property is located to reflect the sale of the Mortgage to
      the
      Trustee, which assignment, notice of transfer or equivalent instrument may
      be in
      the form of one or more blanket assignments covering the Mortgage Loans secured
      by Mortgaged Properties located in the same jurisdiction, if permitted by law;
      provided,
      however,
      that
      none of the Custodians nor the Trustee shall be responsible for determining
      whether any such assignment is in recordable form.

     

    Aurora:
      Aurora
      Loan Services LLC, a Delaware limited liability company.

     

    Authenticating
      Agent:
      Any
      authenticating agent appointed by the Trustee pursuant to Section
      6.10.

     

    Authorized
      Officer:
      Any
      Person who may execute an Officer’s Certificate on behalf of the
      Depositor.

     

    B1
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amounts of
      the
      Senior Certificates and the Class M1, Class M2, Class M3, Class M4, Class M5,
      Class M6, Class M7, Class M8 and Class M9 Certificates, in each case after
      giving effect to distributions on such Distribution Date, and (ii) the Class
      Principal Amount of the Class B1 Certificates immediately prior to such
      Distribution Date exceeds (y) the B1 Target Amount for such Distribution
      Date.

     

    B1
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the excess of (i) the
      lesser of (a) the product of (1) 98.50% and (2) the Pool Balance for such
      Distribution Date determined as of the last day of the related Collection Period
      and (b) the amount, if any, by which (1) the Pool Balance for such Distribution
      Date determined as of the last day of the related Collection Period exceeds
      (2)
      the Overcollateralization Floor over (ii) all prior amounts distributed in
      reduction of the Class Principal Amount of the Class B1 Certificates pursuant
      to
      Section 5.02(d)(iii) of this Agreement.

     

    B2
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amounts of
      the
      Senior Certificates and the Class M1, Class M2, Class M3, Class M4, Class M5,
      Class M6, Class M7, Class M8, Class M9 and Class B1 Certificates, in each case
      after giving effect to distributions on such Distribution Date, and (ii) the
      Class Principal Amount of the Class B2 Certificates immediately prior to such
      Distribution Date exceeds (y) the B2 Target Amount for such Distribution
      Date.

     

    
      
        
        

      

      
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    B2
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the excess of (i) the
      lesser of (a) the product of (1) 98.50% and (2) the Pool Balance for such
      Distribution Date determined as of the last day of the related Collection Period
      and (b) the amount, if any, by which (1) the Pool Balance for such Distribution
      Date determined as of the last day of the related Collection Period exceeds
      (2)
      the Overcollateralization Floor over (ii) all prior amounts distributed in
      reduction of the Class Principal Amount of the Class B2 Certificates pursuant
      to
      Section 5.02(d)(iii) of this Agreement.

     

    Back-Up
      Certification:
      As
      defined in Section 6.20(e)(iv).

     

    Balloon
      Mortgage Loan:
      Any
      Mortgage Loan that provides for (i) equal monthly Scheduled Payments that will
      not reduce the principal balance of such Mortgage Loan to zero at its maturity
      date and (ii) a larger monthly payment due at its maturity date equal to the
      unpaid principal balance of such Mortgage Loan, with interest
      thereon.

     

    Balloon
      Payment:
      The
      final Scheduled Payment in respect of a Balloon Mortgage Loan.

     

    Bankruptcy:
      As to
      any Person, the making of an assignment for the benefit of creditors, the filing
      of a voluntary petition in bankruptcy, adjudication as a bankrupt or insolvent,
      the entry of an order for relief in a bankruptcy or insolvency proceeding,
      the
      seeking of reorganization, arrangement, composition, readjustment, liquidation,
      dissolution or similar relief, or seeking, consenting to or acquiescing in
      the
      appointment of a trustee, receiver or liquidator, dissolution, or termination,
      as the case may be, of such Person pursuant to the provisions of either the
      Bankruptcy Code or any other similar state laws.

     

    Bankruptcy
      Code:
      The
      United States Bankruptcy Code of 1986, as amended.

     

    Basis
      Risk Payment:
      With
      respect to any Distribution Date, the sum of (i) any Basis Risk Shortfall for
      such Distribution Date, (ii) any Unpaid Basis Risk Shortfall for such
      Distribution Date and (iii) any Required Reserve Fund Deposit for such
      Distribution Date. The amount of the Basis Risk Payment for any Distribution
      Date cannot exceed the amount of Monthly Excess Cashflow otherwise available
      for
      distribution pursuant to Section 5.02(d)(v) of this Agreement. 

     

    Basis
      Risk Reserve Fund:
      A fund
      created as part of the Trust Fund pursuant to Section 5.06 of this Agreement
      but
      which is not an asset of any of the REMICs.

     

    Basis
      Risk Shortfall:
      With
      respect to any Distribution Date and any Class of Certificates other than the
      Class X, Class P, Class LT-R and Class R Certificates, the amount by which
      the
      amount of interest calculated at the Certificate Interest Rate applicable to
      such Class for such Distribution Date, determined without regard to the Net
      Funds Cap for such Distribution Date, exceeds the amount of interest calculated
      at the Net Funds Cap for such Class.

     

    Benefit
      Plan Opinion:
      An
      Opinion of Counsel satisfactory to the Depositor and the Trustee to the effect
      that any proposed transfer of Certificates will not (i) cause the assets of
      the
      Trust Fund to be regarded as “plan assets” for purposes of the Plan Asset
      Regulations or (ii) give rise to any fiduciary duty on the part of the Depositor
      or the Trustee, respectively.

     

    
      
        
        

      

      
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    Book-Entry
      Certificates:
      Beneficial interests in Certificates designated as “Book-Entry Certificates” in
      this Agreement, ownership and transfers of which shall be evidenced or made
      through book entries by a Clearing Agency as described in Section 3.09;
provided
      that after
      the
      occurrence of a condition whereupon book-entry registration and transfer are
      no
      longer permitted and Definitive Certificates are to be issued to Certificate
      Owners, such Book-Entry Certificates shall no longer be “Book-Entry
      Certificates.” As of the Closing Date, each of the Certificates other than the
      Class X, Class P, Class LT-R and Class R Certificates constitutes a Book-Entry
      Certificate.

     

    Business
      Day:
      Any day
      other than (i) a Saturday or a Sunday, (ii) a day on which banking institutions
      in New York, New York or, if other than New York, the city in which the
      Corporate Trust Office of the Trustee is located or the State of Colorado are
      closed, or (iii) with respect to any Servicer Remittance Date or any Servicer
      reporting date, the States specified in the definition of “Business Day” in the
      Servicing Agreement, are authorized or obligated by law or executive order
      to be
      closed.

     

    Carryforward
      Interest:
      With
      respect to any Class of Certificates other than the Class X, Class P, Class
      LT-R
      and Class R Certificates and each Distribution Date, the sum of (i) the amount,
      if any, by which (x) the sum of (A) Current Interest for such Class for the
      immediately preceding Distribution Date and (B) any unpaid Carryforward Interest
      for such Class from previous Distribution Dates exceeds (y) the amount
      distributed in respect of interest on such Class on such immediately preceding
      Distribution Date, and (ii) interest on such amount for the related Accrual
      Period at the applicable Certificate Interest Rate.

     

    Certificate:
      Any one
      of the certificates signed and countersigned by the Trustee in substantially
      the
      forms attached hereto as Exhibit A.

     

    Certificate
      Account:
      The
      account maintained by the Trustee in accordance with the provisions of Section
      4.04.

     

    Certificate
      Interest Rate:
      With
      respect to each Class of Certificates and any Distribution Date, the applicable
      per annum rate set forth or described under the heading “The Certificates” in
      the Preliminary Statement hereto.

     

    Certificate
      Owner:
      With
      respect to a Book-Entry Certificate, the Person who is the owner of such
      Book-Entry Certificate, as reflected on the books of the Clearing Agency, or
      on
      the books of a Person maintaining an account with such Clearing Agency (directly
      or as an indirect participant, in accordance with the rules of such Clearing
      Agency).

     

    Certificate
      Principal Amount:
      With
      respect to any Certificate other than a Class X, Class P, Class LT-R or Class
      R
      Certificate, the initial Certificate Principal Amount thereof on the Closing
      Date, less the amount of all principal distributions previously distributed
      with
      respect to such Certificate and, in the case of the Subordinate Certificates,
      any Applied Loss Amount previously allocated to such Certificate; provided,
      however,
      that on
      each Distribution Date on which a Subsequent Recovery is distributed, the
      Certificate Principal Amount of any Class of Subordinate Certificates whose
      Certificate Principal Amount has previously been reduced by application of
      Applied Loss Amounts will be increased, sequentially, in order of seniority,
      by
      an amount (to be applied pro
      rata
      to all
      Certificates of such Class) equal to the lesser of (1) any Deferred Amount
      for
      each such Class immediately prior to such Distribution Date and (2) the total
      amount of any Subsequent Recovery distributed on such Distribution Date to
      Certificateholders, after application for this purpose to any more senior
      Classes of Certificates. The Class X, Class R and Class LT-R Certificates are
      issued without Certificate Principal Amounts. The Class P Certificates are
      issued with an initial Class P Principal Amount of $100.

     

    
      
        
        

      

      
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    Certificate
      Register
      and
Certificate
      Registrar:
      The
      register maintained and the registrar appointed pursuant to Section
      3.02.

     

    Certificateholder:
      The
      meaning provided in the definition of “Holder.”

     

    Certification
      Parties:
      As
      defined in Section 6.20(e)(iv).

     

    Certifying
      Person:
      As
      defined in Section 6.20(e)(iv).

     

    Charged-off
      Loan:
      As of
      any date of determination, any Mortgage Loan other than a Covered Mortgage
      Loan
      that was delinquent in payment for a period of 180 days or more as of the last
      calendar day of the month immediately preceding the month in which such date
      of
      determination occurs, without giving effect to any grace period permitted by
      the
      related Mortgage Note; provided,
      however,
      that
      with respect to any such Mortgage Loan, (i) an equity analysis performed by
      the
      Servicer supports charge-off over foreclosure, (ii) the related Mortgaged
      Property has not become REO Property, (iii) there are no active foreclosure
      or
      other loss mitigation activities and (iv) nothing has come to the attention
      of
      the Servicer indicating that any such Mortgage Loan, at the time of its
      origination, violated any applicable federal, state or local law or regulation,
      including, without limitation, usury, truth-in-lending, consumer credit
      protection and privacy, equal credit opportunity, disclosure or predatory and
      abusive lending laws, applicable to the origination and servicing of such
      Mortgage Loan.

     

    Civil
      Relief Act:
      The
      Servicemembers Civil Relief Act, as amended, or any similar state or local
      statute.

     

    Class:
      All
      Certificates bearing the same class designation, and, in the case of
      REMIC 1, REMIC 2 and REMIC 3, all Lower Tier Interests bearing
      the same class designation.

     

    Class
      B Certificates:
      Collectively, the Class B1 and Class B2 Certificates.

     

    Class
      I Shortfalls:
      As
      defined in Section 10.01(n) hereof. For purposes of clarity, the Class I
      Shortfall for any Distribution Date shall equal the amount payable to the Swap
      Counterparty on such Distribution Date in excess of the amount payable on the
      Class LT3-SIO Interest in REMIC 3 on such Distribution Date, all as further
      provided in Section 10.01(n) hereof.

     

    Class
      LT-R Certificate:
      The
      Class LT-R Certificate executed by the Trustee, and authenticated and delivered
      by the Certificate Registrar, substantially in the form annexed hereto as
      Exhibit A and evidencing the residual interest in REMIC 1.

     

    
      
        
        

      

      
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    Class
      M Certificates:
      Collectively, the Class M1, Class M2, Class M3, Class M4, Class M5, Class M6,
      Class M7, Class M8 and Class M9 Certificates.

     

    Class
      M1 Enhancement Percentage:
      With
      respect to any Distribution Date, the fraction, expressed as a percentage,
      the
      numerator of which is the sum of the aggregate Class Principal Amount of the
      Subordinate Certificates (other than the Class M1 Certificates) and the
      Overcollateralization Amount (which amount, for purposes of this definition
      only, shall not be less than zero and assuming for purposes of this definition
      that the Principal Distribution Amount has been distributed on such Distribution
      Date and no Trigger Event has occurred) and the denominator of which is the
      Pool
      Balance for such Distribution Date, in each case after giving effect to
      distributions on such Distribution Date.

     

    Class
      P Interest:
      An
      interest in the Upper Tier REMIC, as described in the Preliminary Statement,
      which interest shall be evidenced by the rights of the Class P Certificates
      to
      receive Prepayment Premiums.

     

    Class
      P Principal Amount:
      As of
      the Closing Date, $100.

     

    Class
      Principal Amount:
      With
      respect to each Class of Certificates other than the Class X, Class P, Class
      LT-R and Class R Certificates, the aggregate of the Certificate Principal
      Amounts of all Certificates of such Class at the date of determination. With
      respect to the Class X, Class P, Class LT-R and Class R Certificates, zero.
      With
      respect to any Lower Tier Interest, the initial Class Principal Amount as shown
      or described in the table set forth in the Preliminary Statement to this
      Agreement for the issuing REMIC, as reduced by principal distributed with
      respect to such Lower Tier Interest and Realized Losses allocated to such Lower
      Tier Interest.

     

    Class
      R Certificate:
      The
      Class R Certificate executed by the Trustee, and authenticated and delivered
      by
      the Certificate Registrar, substantially in the form annexed hereto as Exhibit
      A
      and evidencing the ownership of the Class LT2-R interest, the Class LT3-R
      interest, and the residual interest in the Upper Tier REMIC.

     

    Class
      X Distributable Amount:
      With
      respect to any Distribution Date, the amount of interest that has accrued on
      the
      Class X Notional Balance, as described in the Preliminary Statement, but that
      has not been distributed prior to such date. In addition, such amount shall
      include the initial Overcollateralization Amount of $3,986,597.32 ($3,986,697.32 less
      $100
      of such amount allocated to the Class P Certificates) to the extent such amount
      has not been distributed on an earlier Distribution Date as part of the
      Aggregate Overcollateralization Release Amount.

     

    Class
      X Notional Balance:
      With
      respect to any Distribution Date (and the related Accrual Period), the aggregate
      principal balance of the regular interests in REMIC 3.

     

    Clearing
      Agency:
      An
      organization registered as a “clearing agency” pursuant to Section 17A of the
      Exchange Act. As of the Closing Date, the Clearing Agency shall be The
      Depository Trust Company.

     

    
      
        
        

      

      
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    Clearing
      Agency Participant:
      A
      broker, dealer, bank, other financial institution or other Person for whom
      from
      time to time a Clearing Agency effects book-entry transfers and pledges of
      securities deposited with the Clearing Agency.

     

    Clearstream:
      Clearstream Banking, S.A., Luxembourg, and any successor thereto.

     

    Closing
      Date:
      December 28, 2006.

     

    Code:
      The
      Internal Revenue Code of 1986, as amended, and as it may be further amended
      from
      time to time, any successor statutes thereto, and applicable U.S. Department
      of
      Treasury regulations issued pursuant thereto in temporary or final
      form.

     

    Collateral
      Account:
      The
      account maintained by the Trustee in accordance with the provisions of Section
      5.07(c).

     

    Collection
      Account:
      A
      separate account established and maintained by the Master Servicer pursuant
      to
      Section 4.01.

     

    Collection
      Period:
      With
      respect to any Distribution Date, the period commencing on the second day of
      the
      calendar month immediately preceding the month in which such Distribution Date
      occurs and ending on the first day of the calendar month in which such
      Distribution Date occurs. 

     

    Combined
      Loan-to-Value Ratio or CLTV:
      With
      respect to any Mortgage Loan at any date of determination, the ratio of the
      principal balance of such Mortgage Loan at the date of determination, plus
      the
      principal balance of each mortgage loan senior thereto based upon the most
      recent information available to the Seller, to (a) in the case of a purchase,
      the lesser of the sale price of the Mortgaged Property and its appraised value
      at the time of sale, or (b) in the case of a refinancing or modification, the
      appraised value of the Mortgaged Property at the time of such refinancing or
      modification.

     

    Commission:
      The
      United States Securities and Exchange Commission.

     

    Compensating
      Interest Payment:
      With
      respect to any Distribution Date, an amount equal to the aggregate amount of
      any
      Prepayment Interest Shortfalls required to be paid by the Servicer with respect
      to such Distribution Date. The Master Servicer shall not be responsible for
      making any Compensating Interest Payment.

     

    Component:
      Not
      applicable.

     

    Component
      Interest Rate:
      Not
      applicable.

     

    Component
      Notional Amount:
      Not
      applicable.

     

    Cooperative
      Corporation:
      Not
      applicable.

     

    Cooperative
      Loan:
      Not
      applicable.

     

    Cooperative
      Loan Documents:
      Not
      applicable.

     

    
      
        
        

      

      
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    Cooperative
      Property:
      Not
      applicable.

     

    Cooperative
      Shares:
      Not
      applicable.

     

    Cooperative
      Unit:
      Not
      applicable.

     

    Controlling
      Person:
      With
      respect to any Person, any other Person who “controls” such Person within the
      meaning of the Securities Act.

     

    Corporate
      Trust Office:
      The
      principal corporate trust office of the Trustee (a) at which Certificates may
      be
      presented for transfer and exchange and for presentment and surrender for the
      final distributions thereon is located at Citibank, N.A., 111 Wall Street,
      15th
      floor, New York, New York 10005, Attention: 15th Floor Window and (b) for all
      other purposes, Citibank, N.A., 388 Greenwich Street, 14th floor, New York,
      New
      York 10013, Attention: Agency and Trust SASCO Series 2006-S4, or such other
      address that the Trustee may designate from time to time by notice to the
      Certificateholders, the Depositor and the Master Servicer.

     

    Corresponding
      Class:
      The
      Class of Certificates that corresponds with a class of Lower Tier Interests
      in
      REMIC 3 as described
      in the
      Preliminary Statement.

     

    Covered
      Mortgage Loan:
      Any
      mortgage loan that is covered by a Primary Mortgage Insurance
      Policy.

     

    Credit
      Risk Management Agreement:
      The
      credit risk management agreement dated as of the Closing Date, entered into
      by
      the Servicer and the Credit Risk Manager, identified on Exhibit L attached
      hereto.

     

    Credit
      Risk Manager:
      Clayton
      Fixed Income Services Inc., a Colorado corporation, and its successors and
      assigns. 

     

    Credit
      Risk Manager’s Fee:
      With
      respect to any Distribution Date and each Mortgage Loan, an amount equal to
      the
      product of (a) one twelfth, (b) the Credit Risk Manager’s Fee Rate and (c) the
      Scheduled Principal Balance of such Mortgage Loan as of the first day of the
      related Collection Period.

     

    Credit
      Risk Manager’s Fee Rate:
      0.009%
      per annum.

     

    Credit
      Support Annex:
      The
      credit support annex to the Swap Agreement dated as of December 28, 2006,
      between the Trustee, not in its individual capacity but solely as trustee on
      behalf of the Supplemental Interest Trust and the Swap
      Counterparty.

     

    Cumulative
      Loss Trigger Event:
      With
      respect to any Distribution Date, a Cumulative Loss Trigger Event shall have
      occurred if the fraction, expressed as a percentage, obtained by dividing (x)
      the aggregate amount of cumulative Realized Losses incurred on the Mortgage
      Loans from the Cut-off Date through the last day of the related Collection
      Period by (y) the Cut-off Date Balance, exceeds the applicable percentages
      described below with respect to such Distribution Date: 

     

    
      
        
        

      

      
        21

        
          

        

      

      
        
        

      

    

     

    
      	
              Distribution
                Date

            	 	
              Loss
                Percentage

            
	
              January
                2009 through December 2009 

            	 	
              2.70%
                for the first month, plus an additional 1/12th of 2.70% for each
                month
                thereafter 

            
	
              January
                2010 through December 2010  

            	 	
              5.40%
                for the first month, plus an additional 1/12th of 2.20% for each
                month
                thereafter 

            
	
              January
                2011 through December 2011  

            	 	
              7.60%
                for the first month, plus an additional 1/12th of 2.15% for each
                month
                thereafter 

            
	
              January
                2012 through December 2012 

            	 	
              9.75%
                for the first month, plus an additional 1/12th of 0.75% for each
                month
                thereafter 

            
	
              January
                2013 and thereafter 

            	 	
              10.50%

            


    

     

    Current
      Interest:
      With
      respect to any Class of Certificates (other than the Class P, Class X, Class
      LT-R and Class R Certificates) and any Distribution Date, the aggregate amount
      of interest accrued at the applicable Certificate Interest Rate during the
      related Accrual Period on the Class Principal Amount of such Class immediately
      prior to such Distribution Date.

     

    Custodial
      Account:
      Any
      custodial account (other than an Escrow Account) established and maintained
      by
      the Servicer pursuant to the Servicing Agreement.

     

    Custodial
      Agreement:
      Each
      custodial agreement identified on Exhibit K hereto, and any custodial agreement
      subsequently executed by the Trustee and acknowledged by the Master Servicer
      substantially in the form thereof.

     

    Custodian:
      Each
      custodian appointed by the Trustee pursuant to a Custodial Agreement, and any
      successor thereto. The initial Custodians are LaSalle Bank National Association
      and U.S. Bank National Association.

     

    Cut-off
      Date:
      December 1, 2006.

     

    Cut-off
      Date Balance:
      The
      Pool Balance as of the Cut-off Date.

     

    Debt
      Service Reduction:
      With
      respect to any Mortgage Loan, a reduction of the Scheduled Payment that the
      related Mortgagor is obligated to pay on any Due Date as a result of, or in
      connection with, any proceeding under Bankruptcy law or any similar proceeding.
      

     

    Defaulting
      Party:
      As
      defined in the Swap Agreement.

     

    Deferred
      Amount:
      With
      respect to any Distribution Date and each Class of the Subordinate Certificates,
      the amount by which (x) the aggregate of Applied Loss Amounts previously applied
      in reduction of the Class Principal Amount thereof exceeds (y) the sum of (1)
      the aggregate of amounts previously reimbursed in respect thereof and (2) the
      amount by which the Class Principal Amount of such Class has been increased
      due
      to any Subsequent Recovery.

     

    
      
        
        

      

      
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    Definitive
      Certificate:
      A
      Certificate of any Class issued in definitive, fully registered, certificated
      form.

     

    Deleted
      Mortgage Loan:
      A
      Mortgage Loan that is repurchased from the Trust Fund pursuant to the terms
      hereof or as to which one or more Qualifying Substitute Mortgage Loans are
      substituted therefor.

     

    Delinquency
      Event:
      With
      respect to any Distribution Date, a Delinquency Event shall have occurred if
      the
      Rolling Three Month Delinquency Rate as of the last day of the immediately
      preceding calendar month equals or exceeds (i) 13.00% of the Senior Enhancement
      Percentage for such Distribution Date or (ii) with respect to any Distribution
      Date on which the Class Principal Amount of the Class A Certificates has been
      reduced to zero, 15.90% of the Class M1 Enhancement Percentage.

     

    Delinquency
      Rate:
      With
      respect to any calendar month, the fraction, expressed as a percentage, the
      numerator of which is the aggregate outstanding principal balance of
      (i) all Mortgage Loans 60 days Delinquent or more (including each Mortgage
      Loan 60 days Delinquent or more for which the Mortgagor has filed for Bankruptcy
      after the Closing Date) and (ii) each Mortgage Loan in foreclosure and all
      REO
      Properties as of the close of business on the last day of such month, and the
      denominator of which is the Pool Balance as of the close of business on the
      last
      day of such month.

     

    Delinquent:
      For
      reporting purposes, a Mortgage Loan is “delinquent” when any payment
      contractually due thereon has not been made by the close of business on the
      Due
      Date therefor. Such Mortgage Loan is “30 days Delinquent” if such payment has
      not been received by the close of business on the corresponding day of the
      month
      immediately succeeding the month in which such payment was first due, or, if
      there is no such corresponding day (e.g.,
      as when
      a 30-day month follows a 31-day month in which a payment was due on the 31st
      day
      of such month), then on the last day of such immediately succeeding month.
      Similarly for “60 days Delinquent” and the second immediately succeeding month
      and “90 days Delinquent” and the third immediately succeeding
      month.

     

    Depositor:
      Structured Asset Securities Corporation, a Delaware corporation, having its
      principal place of business in New York, or its successors in
      interest.

     

    Determination
      Date:
      With
      respect to each Distribution Date, the 18th day of the month in which such
      Distribution Date occurs, or, if such 18th day is not a Business Day, the next
      succeeding Business Day.

     

    Disqualified
      Organization:
      A
“disqualified organization” as defined in Section 860E(e)(5) of the
      Code.

     

    Distressed
      Mortgage Loan:
      Not
      applicable.

     

    Distribution
      Date:
      The
      25th day of each month or, if such 25th day is not a Business Day, the next
      succeeding Business Day, commencing in January 2007.

     

    Distribution
      Date Statement:
      As
      defined in Section 4.03(a) hereof.

     

    
      
        
        

      

      
        23

        
          

        

      

      
        
        

      

    

     

    Due
      Date:
      With
      respect to any Mortgage Loan, the date on which a Scheduled Payment is due
      under
      the related Mortgage Note.

     

    Eligible
      Account:
      Either
      (i) an account or accounts maintained with a federal or state chartered
      depository institution or trust company acceptable to the Rating Agencies or
      (ii) an account or accounts the deposits in which are insured by the FDIC to
      the
      limits established by such corporation, provided
      that any
      such deposits not so insured shall be maintained in an account at a depository
      institution or trust company whose commercial paper or other short term debt
      obligations (or, in the case of a depository institution or trust company which
      is the principal subsidiary of a holding company, the commercial paper or other
      short term debt or deposit obligations of such holding company or depository
      institution, as the case may be) have been rated by each Rating Agency in its
      highest short-term rating category, or (iii) a segregated trust account or
      accounts (which shall be a “special deposit account”) maintained with the
      Trustee or any other federal or state chartered depository institution or trust
      company, acting in its fiduciary capacity, in a manner acceptable to the Trustee
      and the Rating Agencies. Eligible Accounts may bear interest.

     

    Eligible
      Investments:
      Any one
      or more of the following obligations or securities:

     

    (i) direct
      obligations of, and obligations fully guaranteed as to timely payment of
      principal and interest by, the United States of America or any agency or
      instrumentality of the United States of America the obligations of which are
      backed by the full faith and credit of the United States of America
      (“Direct
      Obligations”);

     

    (ii) federal
      funds, or demand and time deposits in, certificates of deposits of, or bankers’
acceptances issued by, any depository institution or trust company (including
      U.S. subsidiaries of foreign depositories and the Trustee or any agent of the
      Trustee, acting in its respective commercial capacity) incorporated or organized
      under the laws of the United States of America or any state thereof and subject
      to supervision and examination by federal or state banking authorities, so
      long
      as at the time of investment or the contractual commitment providing for such
      investment the commercial paper or other short-term debt obligations of such
      depository institution or trust company (or, in the case of a depository
      institution or trust company which is the principal subsidiary of a holding
      company, the commercial paper or other short-term debt or deposit obligations
      of
      such holding company or deposit institution, as the case may be) have been
      rated
      by each Rating Agency in its highest short-term rating category or one of its
      two highest long-term rating categories;

     

    (iii) repurchase
      agreements collateralized by Direct Obligations or securities guaranteed by
      GNMA, FNMA or FHLMC with any registered broker/dealer subject to Securities
      Investor Protection Corporation jurisdiction or any commercial bank insured
      by
      the FDIC, if such broker/dealer or bank has an uninsured, unsecured and
      unguaranteed obligation rated by each Rating Agency in its highest short-term
      rating category;

     

    (iv) securities
      bearing interest or sold at a discount issued by any corporation incorporated
      under the laws of the United States of America or any state thereof which have
      a
      credit rating from each Rating Agency, at the time of investment or the
      contractual commitment providing for such investment, at least equal to (a)
      one
      of the two highest short-term credit rating categories of S&P and Moody’s
      and (b) the highest short-term rating category of Fitch (if Fitch is a Rating
      Agency); provided,
      however,
      that
      securities issued by any particular corporation will not be Eligible Investments
      to the extent that investment therein will cause the then outstanding principal
      amount of securities issued by such corporation and held as part of the Trust
      Fund to exceed 20% of the sum of the Pool Balance and the aggregate principal
      amount of all Eligible Investments in the Certificate Account; provided,
      further,
      that
      such securities will not be Eligible Investments if they are published as being
      under review with negative implications from any Rating Agency;

     

    
      
        
        

      

      
        24

        
          

        

      

      
        
        

      

    

     

    (v) commercial
      paper (including both non-interest-bearing discount obligations and
      interest-bearing obligations payable on demand or on a specified date not more
      than 180 days after the date of issuance thereof) rated by each Rating Agency
      in
      its highest short-term rating category;

     

    (vi) a
      Qualified GIC;

     

    (vii) certificates
      or receipts representing direct ownership interests in future interest or
      principal payments on obligations of the United States of America or its
      agencies or instrumentalities (which obligations are backed by the full faith
      and credit of the United States of America) held by a custodian in safekeeping
      on behalf of the holders of such receipts; and

     

    (viii) any
      other
      demand, money market, common trust fund or time deposit or obligation, or
      interest-bearing or other security or investment (including those managed or
      advised by the Trustee or any Affiliate thereof), (A) rated in the highest
      rating category by each Rating Agency rating such investment or (B) that would
      not adversely affect the then current rating assigned by each Rating Agency
      of
      any of the Certificates and has a short term rating of at least “A-1” or its
      equivalent by each Rating Agency. Such investments in this subsection (viii)
      may
      include money market mutual funds or common trust funds, including any fund
      for
      which Citibank, N.A. (the “Bank”), in its capacity other than as Trustee, the
      Trustee, the Master Servicer or an affiliate of any such entity serves as an
      investment advisor, administrator, shareholder servicing agent, and/or custodian
      or subcustodian, notwithstanding that (x) the Bank, the Trustee, the Master
      Servicer or any affiliate of any such entity charges and collects fees and
      expenses from such funds for services rendered, (y) the Bank, the Trustee,
      the
      Master Servicer or any affiliate of any such entity charges and collects fees
      and expenses for services rendered pursuant to this Agreement, and (z) services
      performed for such funds and pursuant to this Agreement may converge at any
      time. The Bank or an affiliate thereof is authorized hereby to charge and
      collect from the Trustee such fees as are collected from all investors in such
      funds for services rendered to such funds (but not to exceed investment earnings
      thereon);

     

    provided,
      however,
      that no
      such instrument shall be an Eligible Investment if such instrument evidences
      either (i) a right to receive only interest payments with respect to the
      obligations underlying such instrument, or (ii) both principal and interest
      payments derived from obligations underlying such instrument and the principal
      and interest payments with respect to such instrument provide a yield to
      maturity of greater than 120% of the yield to maturity at par of such underlying
      obligations, provided
      that any
      such investment will be a “permitted investment” within the meaning of Section
      860G(a)(5) of the Code.

     

    
      
        
        

      

      
        25

        
          

        

      

      
        
        

      

    

     

    Enhancement
      Target:
      With
      respect to any Distribution Date prior to the Stepdown Date, an amount equal
      to
      $38,274,697.32 (approximately 7.20% of the Cut-off Date Balance). With respect
      to any Distribution Date on or after the Stepdown Date and for which a Trigger
      Event is not in effect, an amount equal to the greater of (i) the lesser of
      (a)
      an amount equal to $38,274,697.32 (approximately 7.20% of the Cut-off Date
      Balance) and (b) 14.40% of the Pool Balance, after giving effect to
      distributions on that Distribution Date, and (ii) the Overcollateralization
      Floor. With respect to any Distribution Date on or after the Stepdown Date
      and
      for which a Trigger Event is in effect, an amount equal to the Enhancement
      Target for the immediately preceding Distribution Date.

     

    ERISA:
      The
      Employee Retirement Income Security Act of 1974, as amended.

     

    ERISA-Qualifying
      Underwriting:
      A best
      efforts or firm commitment underwriting or private placement that meets the
      requirements of an Underwriter’s Exemption.

     

    ERISA-Restricted
      Certificate:
      Any
      Class B1, Class B2, Class X, Class R or Class LT-R Certificate, and any
      Offered Certificate with a rating below the lowest applicable rating permitted
      under the Underwriter’s Exemption.

     

    ERISA-Restricted
      Swap Certificate:
      Any
      Senior Certificate and any Class M Certificate.

     

    Errors
      and Omission Insurance Policy:
      The
      errors or omission insurance policy required to be obtained by the Servicer
      satisfying the requirements of the Servicing Agreement.

     

    Escrow
      Account:
      Any
      account established and maintained by the Servicer pursuant to the Servicing
      Agreement.

     

    Euroclear:
      Euroclear Bank, S.A./N.V., as operator of the Euroclear System.

     

    Event
      of Default:
      Any one
      of the conditions or circumstances enumerated in Section 6.14(a).

     

    Exchange
      Act:
      The
      Securities Exchange Act of 1934, as amended.

     

    Exchange
      Act Signing Party:
      Either
      the Depositor or the Master Servicer, to be determined by mutual agreement
      between such parties.

     

    Excluded
      Trust Assets:
      As
      described in the Preliminary Statement.

     

    Fannie
      Mae or FNMA:
      Fannie
      Mae, f/k/a the Federal National Mortgage Association, a federally chartered
      and
      privately owned corporation organized and existing under the Federal National
      Mortgage Association Charter Act, or any successor thereto.

     

    FDIC:
      The
      Federal Deposit Insurance Corporation or any successor thereto.

     

    
      
        
        

      

      
        26

        
          

        

      

      
        
        

      

    

     

    Fidelity
      Bond:
      The
      fidelity bond required to be obtained by the Servicer satisfying the
      requirements of the Servicing Agreement.

     

    Final
      Scheduled Distribution Date:
      The
      Distribution Date in January 2037. 

     

    Financial
      Intermediary:
      A
      broker, dealer, bank or other financial institution or other Person that clears
      through or maintains a custodial relationship with a Clearing Agency
      Participant.

     

    First
      Payment Default Mortgage Loan:
      Any
      Mortgage Loan originated by the Lehman Brothers Bank, FSB specified in Section
      1.04(e) of the Mortgage Loan Sale Agreement in respect of which the related
      Mortgagor does not make the first, or first or second, payment due to the Seller
      within the time frame required under such section.

     

    Fitch:
      Fitch
      Ratings, Inc., or any successor in interest.

     

    Fixed
      Rate Mortgage Loan:
      Any
      Mortgage Loan as to which the related Mortgage Note provides for a fixed rate
      of
      interest throughout the term of such Note.

     

    Form
      8-K Disclosure Information:
      As
      defined in Section 6.20(f)(i).

     

    Form
      10-K Certification:
      The
      certification required pursuant to Rule 13a-14 under the Exchange
      Act.

     

    Freddie
      Mac or FHLMC:
      Freddie
      Mac, f/k/a the Federal Home Loan Mortgage Corporation, a corporate
      instrumentality of the United States created and existing under Title III of
      the
      Emergency Home Finance Act of 1970, as amended, or any successor
      thereto.

     

    Global
      Securities:
      The
      global certificates representing the Book-Entry Certificates.

     

    GNMA:
      The
      Government National Mortgage Association, a wholly owned corporate
      instrumentality of the United States within HUD.

     

    Holder
      or
Certificateholder:
      The
      registered owner of any Certificate as recorded on the books of the Certificate
      Registrar except that, solely for the purposes of taking any action or giving
      any consent pursuant to this Agreement, any Certificate registered in the name
      of the Depositor, the Trustee, the Master Servicer, the Servicer, the Credit
      Risk Manager or any Affiliate of any such entity shall be deemed not to be
      outstanding in determining whether the requisite percentage necessary to effect
      any such consent has been obtained, except that, in determining whether the
      Trustee shall be protected in relying upon any such consent, only Certificates
      which a Responsible Officer of the Trustee knows to be so owned shall be
      disregarded. The Trustee may request and conclusively rely on certifications
      by
      the Depositor, the Master Servicer, the Credit Risk Manager or the Servicer,
      in
      determining whether any Certificates are registered to an Affiliate of the
      Depositor, the Master Servicer, the Credit Risk Manager or the Servicer. After
      a
      Section 7.01(c) Purchase Event, other than in Sections 5.02(b) through (g)
      and
      11.03(a) and (b) and, except in the case of the Class LT-R Certificates,
      Sections 3.03, 3.04, 3.05, 3.06, 3.07 and 3.09 herein, all references in this
      Agreement to “Holder” or “Certificateholder” shall be deemed to be references to
      the LTURI-holder, as recorded on the books of the Certificate Registrar, as
      holder of the Lower Tier Uncertificated REMIC 1 Regular Interests.

     

    
      
        
        

      

      
        27

        
          

        

      

      
        
        

      

    

     

    HUD:
      The
      United States Department of Housing and Urban Development, or any successor
      thereto.

     

    Independent:
      When
      used with respect to any Accountants, a Person who is “independent” within the
      meaning of Rule 2-01(b) of the Commission’s Regulation S-X. When used with
      respect to any other Person, a Person who (a) is in fact independent of another
      specified Person and any Affiliate of such other Person, (b) does not have
      any
      material direct financial interest in such other Person or any Affiliate of
      such
      other Person, (c) is not connected with such other Person or any Affiliate
      of
      such other Person as an officer, employee, promoter, underwriter, trustee,
      partner, director or Person performing similar functions and (d) is not a member
      of the immediate family of a Person defined in clause (b) or (c)
      above.

     

    Index:
      Not
      applicable.

     

    Initial
      LIBOR Rate:
      5.350%
      per annum.

     

    Initial
      Optional Termination Date:
      The
      first Distribution Date following the date on which the Pool Balance is less
      than 10.00% of the Cut-off Date Balance.

     

    Insurance
      Fee Rate:
      With
      respect to each Mortgage Loan insured by an Insurance Policy paid for by the
      lender, the per annum rate specified in the Mortgage Loan Schedule.

     

    Insurance
      Policy:
      Any
      Primary Mortgage Insurance Policy, any standard hazard insurance policy, flood
      insurance policy, earthquake insurance policy or title insurance policy relating
      to the Mortgage Loans or the Mortgaged Properties, to be in effect as of the
      Closing Date or thereafter during the term of this Agreement.

     

    Insurance
      Proceeds:
      Amounts
      paid by the insurer under any Insurance Policy, other than amounts (i) to cover
      expenses incurred by or on behalf of the Servicer or the Master Servicer in
      connection with procuring such proceeds, (ii) to be applied to restoration
      or
      repair of the related Mortgaged Property or (iii) required to be paid over
      to
      the Mortgagor pursuant to law or the related Mortgage Note.

     

    Interest-Only
      Certificates:
      Not
      applicable.

     

    Interest
      Remittance Amount:
      With
      respect to any Distribution Date, an amount equal to (a) the sum of (1) all
      interest collected (other than Payaheads and Prepayment Premiums) or advanced
      in
      respect of Scheduled Payments on the Mortgage Loans during the related
      Collection Period by the Servicer, the Master Servicer or the Trustee (solely
      in
      its capacity as successor master servicer), minus
      (x) the
      Servicing Fee with respect to such Mortgage Loans and (y) previously
      unreimbursed Advances due to the Servicer, the Master Servicer or the Trustee
      (solely in its capacity as successor master servicer) to the extent allocable
      to
      interest and the allocable portion of previously unreimbursed Servicing Advances
      with respect to such Mortgage Loans, (2) any amounts actually paid by the
      Servicer with respect to any Compensating Interest Payments with respect to
      such
      Mortgage Loans and the related Prepayment Period, (3) the portion of any
      Purchase Price or Substitution Amount paid with respect to such Mortgage Loans
      during the related Prepayment Period allocable to interest and (4) all Net
      Liquidation Proceeds, Insurance Proceeds, any Subsequent Recovery and any other
      recoveries collected with respect to such Mortgage Loans during the related
      Prepayment Period, to the extent allocable to interest, as reduced by
      (b) any other costs, expenses or liabilities reimbursable to the Trustee,
      the Master Servicer, each Custodian and the Servicer to the extent provided
      in
      this Agreement, each Custodial Agreement and the Servicing Agreement;
provided,
      however,
      that in
      the case of the Trustee, such reimbursable amounts to the Trustee pursuant
      to
      Section 4.04(b)(i) may not exceed $200,000 during any Anniversary Year. In
      the
      event that the Trustee incurs reimbursable amounts in excess of $200,000, it
      may
      seek reimbursement for such amounts in subsequent Anniversary Years, but in
      no
      event shall more than $200,000 be reimbursed to the Trustee per Anniversary
      Year. Notwithstanding the foregoing, costs and expenses incurred by the Trustee
      pursuant to Section 6.14(a) in connection with any transfer of servicing shall
      be excluded from the $200,000 per Anniversary Year limit on reimbursable
      amounts. For the avoidance of doubt, (i) the Interest Remittance Amount
      available on each Swap Payment Date for distributions to the Swap Account shall
      be equal to the Interest Remittance Amount on the related Distribution Date
      and
      (ii) the Interest Remittance Amount for each Distribution Date shall be
      calculated without regard to any distributions to the Swap Account on the
      related Swap Payment Date.

     

    
      
        
        

      

      
        28

        
          

        

      

      
        
        

      

    

     

    Intervening
      Assignments:
      The
      original intervening assignments of the Mortgage, notices of transfer or
      equivalent instrument.

     

    Item
      1122 Responsible Party:
      With
      respect to the criteria to be addressed under Item 1122 of Regulation AB, the
      attesting party as indicated in the table attached hereto at Exhibit
      T.

     

    Latest
      Possible Maturity Date:
      The
      Distribution Date occurring in January 2042.

     

    LBH:
      Lehman
      Brothers Holdings Inc., or any successor in interest.

     

    LIBOR:
      With
      respect to the first Accrual Period, the Initial LIBOR Rate. With respect to
      each subsequent Accrual Period, a per annum rate determined on the LIBOR
      Determination Date in the following manner by the Trustee on the basis of the
      “Interest Settlement Rate” set by the British Bankers’ Association (the “BBA”)
      for one-month United States dollar deposits, as such rates appear on the
      Telerate Page 3750, as of 11:00 a.m. (London time) on such LIBOR Determination
      Date.

     

    If
      on
      such a LIBOR Determination Date, the BBA’s
      Interest Settlement Rate does not appear on the Telerate Page 3750 as of 11:00
      a.m. (London time), or if the Telerate Page 3750 is not available on such date,
      the Trustee will obtain such rate from Reuters’ “page LIBOR 01” or Bloomberg’s
      page “BBAM.” If such rate is not published for such LIBOR Determination Date,
      LIBOR for such date will be the most recently published Interest Settlement
      Rate. In the event that the BBA no longer sets an Interest Settlement Rate,
      the
      Trustee will designate an alternative index that has performed, or that the
      Trustee expects to perform, in a manner substantially similar to the BBA’s
      Interest Settlement Rate. The Trustee will select a particular index as the
      alternative index only if it receives an Opinion of Counsel, which opinion
      shall
      be an expense reimbursed from the Certificate Account pursuant to Section 4.04,
      that the selection of such index will not cause any of the REMICs to lose their
      classification as REMICs for federal income tax purposes.

     

    
      
        
        

      

      
        29

        
          

        

      

      
        
        

      

    

     

    The
      establishment of LIBOR by the Trustee and the Trustee’s subsequent calculation
      of the Certificate Interest Rate applicable to the LIBOR Certificates for the
      relevant Accrual Period, in the absence of manifest error, will be final and
      binding.

     

    LIBOR
      Business Day:
      Any day
      on which banks in London, England and The City of New York are open and
      conducting transactions in foreign currency and exchange.

     

    LIBOR
      Certificates:
      Collectively, the Class A, Class M1, Class M2, Class M3, Class M4, Class M5,
      Class M6, Class M7, Class M8, Class M9, Class B1 and Class B2
      Certificates.

     

    LIBOR
      Determination Date:
      The
      second LIBOR Business Day immediately preceding the commencement of each Accrual
      Period for any LIBOR Certificates.

     

    Liquidated
      Mortgage Loan:
      Any
      Charged-off Loan or defaulted Mortgage Loan as to which the Master Servicer
      or
      the Servicer has determined that all amounts that it expects to recover on
      behalf of the Trust Fund from or on account of such Mortgage Loan have been
      recovered (exclusive of any possibility of a deficiency judgment).

     

    Liquidation
      Expenses:
      Expenses that are incurred by the Master Servicer or the Servicer in connection
      with the liquidation of any defaulted Mortgage Loan and are not recoverable
      under any Insurance Policy, if any, including, without limitation, foreclosure
      and rehabilitation expenses, legal expenses and unreimbursed amounts, if any,
      expended pursuant to Sections 9.06, 9.16 or 9.22.

     

    Liquidation
      Proceeds:
      Cash
      received in connection with the liquidation of a defaulted Mortgage Loan,
      whether through the sale or assignment of such Mortgage Loan, trustee’s sale,
      foreclosure sale, payment in full, discounted payoff, condemnation proceeds,
      Insurance Proceeds or otherwise, or the sale of the related Mortgaged Property
      if the Mortgaged Property is acquired in satisfaction of the Mortgage Loan
      by
      foreclosure or deed in lieu of foreclosure, including any amounts remaining
      in
      the related Escrow Account.

     

    Loan-to-Value
      Ratio:
      With
      respect to any Mortgage Loan, the ratio of the principal balance of such
      Mortgage Loan at origination, or such other date as is specified, to the
      Original Value of the related Mortgaged Property.

     

    Lower
      Tier Interest:
      As
      described in the Preliminary Statement.

     

    Lower
      Tier REMIC 1 Uncertificated Regular Interests:
      Lower
      Tier Interests of REMIC 1 constituting regular interests held in uncertificated
      form pursuant to a Section 7.01(c) Purchase Event.

     

    LTURI-holder:
      The
      holder of Lower Tier REMIC 1 Uncertificated Regular Interests, which upon the
      occurrence of a Section 7.01(c) Purchase Event shall be the Master Servicer
      or
      its designee, including any trustee in its capacity as trustee of any privately
      placed securitization.

     

    M1
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amount of the
      Senior Certificates after giving effect to distributions on such Distribution
      Date and (ii) the Class Principal Amount of the Class M1 Certificates
      immediately prior to such Distribution Date exceeds (y) the M1 Target Amount
      for
      such Distribution Date.

     

    
      
        
        

      

      
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    M1
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (1) 49.80% and (2) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period immediately
      prior
      to such Distribution Date and (b) the amount, if any, by which (1) the Pool
      Balance for such Distribution Date determined as of the last day of the related
      Collection Period exceeds (2) the Overcollateralization Floor.

     

    M2
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amount of the
      Senior Certificates and the Class M1 Certificates, in each case, after giving
      effect to distributions on such Distribution Date, and (ii) the Class Principal
      Amount of the Class M2 Certificates immediately prior to such Distribution
      Date
      exceeds (y) the M2 Target Amount for such Distribution Date.

     

    M2
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (1) 60.20% and (2) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period immediately
      prior
      to such Distribution Date and (b) the amount, if any, by which (1) the Pool
      Balance for such Distribution Date determined as of the last day of the related
      Collection Period exceeds (2) the Overcollateralization Floor.

     

    M3
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amounts of
      the
      Senior Certificates and the Class M1 and Class M2 Certificates, in each case
      after giving effect to distributions on such Distribution Date, and (ii) the
      Class Principal Amount of the Class M3 Certificates immediately prior to such
      Distribution Date exceeds (y) the M3 Target Amount for such Distribution
      Date.

     

    M3
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (1) 64.60% and (2) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period immediately
      prior
      to such Distribution Date and (b) the amount, if any, by which (1) the Pool
      Balance for such Distribution Date determined as of the last day of the related
      Collection Period exceeds (2) the Overcollateralization Floor.

     

    M4
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amounts of
      the
      Senior Certificates and the Class M1, Class M2 and Class M3 Certificates, in
      each case after giving effect to distributions on such Distribution Date, and
      (ii) the Class Principal Amount of the Class M4 Certificates immediately prior
      to such Distribution Date exceeds (y) the M4 Target Amount for such Distribution
      Date.

     

    M4
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (1) 69.80% and (2) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period immediately
      prior
      to such Distribution Date and (b) the amount, if any, by which (1) the Pool
      Balance for such Distribution Date determined as of the last day of the related
      Collection Period exceeds (2) the Overcollateralization Floor.

     

    
      
        
        

      

      
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    M5
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amounts of
      the
      Senior Certificates and the Class M1, Class M2, Class M3 and Class M4
      Certificates, in each case after giving effect to distributions on such
      Distribution Date, and (ii) the Class Principal Amount of the Class M5
      Certificates immediately prior to such Distribution Date exceeds (y) the M5
      Target Amount for such Distribution Date.

     

    M5
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (1) 73.40% and (2) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period immediately
      prior
      to such Distribution Date and (b) the amount, if any, by which (1) the Pool
      Balance for such Distribution Date determined as of the last day of the related
      Collection Period exceeds (2) the Overcollateralization Floor.

     

    M6
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amounts of
      the
      Senior Certificates and the Class M1, Class M2, Class M3, Class M4 and Class
      M5
      Certificates, in each case after giving effect to distributions on such
      Distribution Date, and (ii) the Class Principal Amount of the Class M6
      Certificates immediately prior to such Distribution Date exceeds (y) the M6
      Target Amount for such Distribution Date.

     

    M6
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (1) 76.40% and (2) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period immediately
      prior
      to such Distribution Date and (b) the amount, if any, by which (1) the Pool
      Balance for such Distribution Date determined as of the last day of the related
      Collection Period exceeds (2) the Overcollateralization Floor.

     

    M7
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amounts of
      the
      Senior Certificates and the Class M1, Class M2, Class M3, Class M4, Class M5
      and
      Class M6 Certificates, in each case after giving effect to distributions on
      such
      Distribution Date, and (ii) the Class Principal Amount of the Class M7
      Certificates immediately prior to such Distribution Date exceeds (y) the M7
      Target Amount for such Distribution Date.

     

    M7
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (1) 80.10% and (2) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period immediately
      prior
      to such Distribution Date and (b) the amount, if any, by which (1) the Pool
      Balance for such Distribution Date determined as of the last day of the related
      Collection Period exceeds (2) the Overcollateralization Floor.

     

    M8
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amounts of
      the
      Senior Certificates and the Class M1, Class M2, Class M3, Class M4, Class M5,
      Class M6 and Class M7 Certificates, in each case after giving effect to
      distributions on such Distribution Date, and (ii) the Class Principal Amount
      of
      the Class M8 Certificates immediately prior to such Distribution Date exceeds
      (y) the M8 Target Amount for such Distribution Date.

     

    
      
        
        

      

      
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    M8
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (1) 82.80% and (2) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period immediately
      prior
      to such Distribution Date and (b) the amount, if any, by which (1) the Pool
      Balance for such Distribution Date determined as of the last day of the related
      Collection Period exceeds (2) the Overcollateralization Floor.

     

    M9
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      amount, if any, by which (x) the sum of (i) the Class Principal Amounts of
      the
      Senior Certificates and the Class M1, Class M2, Class M3, Class M4, Class M5,
      Class M6, Class M7 and Class M8 Certificates, in each case after giving effect
      to distributions on such Distribution Date, and (ii) the Class Principal Amount
      of the Class M9 Certificates immediately prior to such Distribution Date exceeds
      (y) the M9 Target Amount for such Distribution Date.

     

    M9
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (1) 85.60% and (2) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period immediately
      prior
      to such Distribution Date and (b) the amount, if any, by which (1) the Pool
      Balance for such Distribution Date determined as of the last day of the related
      Collection Period exceeds (2) the Overcollateralization Floor.

     

    Master
      Servicer:
      Aurora
      Loan Services LLC, or any successor in interest, or if any successor master
      servicer shall be appointed as herein provided, then such successor master
      servicer.

     

    Master
      Servicer Remittance Date:
      With
      respect to each Distribution Date, two (2) Business Days immediately preceding
      such Distribution Date.

     

    Master
      Servicing Fee:
      As to
      any Distribution Date, an amount equal to one-twelfth the product of (a) the
      Master Servicing Fee Rate and (b) the outstanding principal balance of each
      Mortgage Loan.

     

    Master
      Servicing Fee Rate:
      0.00%
      per annum.

     

    Material
      Defect:
      As
      defined in Section 2.02(c) hereof.

     

    MERS:
      Mortgage Electronic Registration Systems, Inc., a Delaware corporation, or
      any
      successor in interest thereto.

     

    MERS
      Mortgage Loan:
      Any
      Mortgage Loan as to which the related Mortgage, or an Assignment of Mortgage,
      has been or will be recorded in the name of MERS, as nominee for the holder
      from
      time to time of the Mortgage Note.

     

    
      
        
        

      

      
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    Monthly
      Excess Cashflow:
      With
      respect to any Distribution Date, the sum of (x) the Monthly Excess Interest
      for
      such Distribution Date, (y) the Aggregate Overcollateralization Release Amount
      for such Distribution Date and (z) the Monthly Excess Principal for such
      Distribution Date. 

     

    Monthly
      Excess Interest:
      With
      respect to any Distribution Date, the amount of any Interest Remittance Amount
      remaining after application pursuant to clauses (i) through (v) of Section
      5.02(b) on such Distribution Date.

     

    Monthly
      Excess Principal:
      With
      respect to any Distribution Date, the amount of any Principal Distribution
      Amount remaining after application pursuant to clauses (A) through (C) of
      Section 5.02(c)(i) or clauses (A) through (M) of Section 5.02(c)(ii) on such
      Distribution Date.

     

    Moody’s:
      Moody’s
      Investors Service, Inc., or any successor in interest.

     

    Mortgage:
      A
      mortgage, deed of trust or other instrument encumbering a fee simple interest
      in
      real property securing a Mortgage Note, together with improvements
      thereto.

     

    Mortgage
      File:
      The
      mortgage documents listed in Section 2.01(b) pertaining to a particular Mortgage
      Loan required to be delivered to the Trustee pursuant to this
      Agreement.

     

    Mortgage
      Loan:
      A
      Mortgage and the related notes or other evidences of indebtedness secured by
      each such Mortgage conveyed, transferred, sold, assigned to or deposited with
      the Trustee pursuant to Section 2.01 or Section 2.05, including without
      limitation, each Mortgage Loan listed on the Mortgage Loan Schedule, as amended
      from time to time. Any Released Mortgage Loan shall not be considered a Mortgage
      Loan subject to this Agreement.

     

    Mortgage
      Loan Sale Agreement:
      The
      mortgage loan sale and assignment agreement dated as of December 1, 2006,
      for the sale of the Mortgage Loans by the Seller to the Depositor.

     

    Mortgage
      Loan Schedule:
      The
      schedule attached hereto as Schedule A, which shall identify each Mortgage
      Loan,
      as such schedule may be amended from time to time to reflect the addition of
      Mortgage Loans to, or the deletion of Mortgage Loans from, the Trust Fund.
      Such
      schedule shall set forth, among other things, the following information with
      respect to each Mortgage Loan: (i) the Mortgage Loan identifying number; (ii)
      the city, state and zip code of the Mortgaged Property; (iii) the original
      principal amount of the Mortgage Loan; (iv) the Mortgage Rate; (v) the monthly
      payment of principal and interest at origination; (vi) the Servicer
      servicing such Mortgage Loan and the Servicing Fee Rate; (vii) the Custodian
      with respect to the Mortgage File related to such Mortgage Loan; (viii) whether
      such Mortgage Loan is subject to a Prepayment Premium for voluntary prepayments
      by the Mortgagor, the term during which such Prepayment Premiums are imposed
      and
      the method(s) of calculation of the Prepayment Premium; and (ix) whether such
      Mortgage Loan is a First Payment Default Mortgage Loan. The Depositor shall
      be
      responsible for providing the Trustee and the Master Servicer with all
      amendments to the Mortgage Loan Schedule.

     

    Mortgage
      Note:
      The
      note or other evidence of the indebtedness of a Mortgagor secured by a Mortgage
      under a Mortgage Loan.

     

    
      
        
        

      

      
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    Mortgage
      Rate:
      With
      respect to any Mortgage Loan, the per annum rate at which interest accrues
      on
      such Mortgage Loan, as determined under the related Mortgage Note as reduced
      by
      any Relief Act Reductions.

     

    Mortgaged
      Property:
      The fee
      simple interest in real property, together with improvements thereto including
      any exterior improvements to be completed within 120 days of disbursement of
      the
      related Mortgage Loan proceeds.

     

    Mortgagor:
      The
      obligor on a Mortgage Note.

     

    Net
      Excess Spread:
      With
      respect to any Distribution Date, (A) the fraction, expressed as a percentage,
      the numerator of which is equal to the product of (i) the amount, if any, by
      which (a) the Interest Remittance Amount for such Distribution Date (as reduced
      by the aggregate Credit Risk Manager’s Fee) exceeds (b) the Current Interest
      payable with respect to the Certificates for such date and (ii) twelve, and
      the
      denominator of which is the Pool Balance for such Distribution Date,
multiplied
      by (B) a
      fraction, the numerator of which is thirty and the denominator of which is
      the
      greater of thirty and the actual number of days in the immediately preceding
      calendar month minus
      (C)
      the
      product, expressed as a percentage, of (i) the amount of any Net Swap Payment
      owed to the Swap Counterparty for such Distribution Date divided by the Pool
      Balance as of the beginning of the related Collection Period and (ii) a
      fraction, the numerator of which is 360 and the denominator of which is the
      actual number of days in the Accrual Period related to such Distribution Date,
      plus
      (D)
      the
      product, expressed as a percentage, of (i) the amount of any Net Swap Payment
      received by the Supplemental Interest Trust for such Distribution Date divided
      by the Pool Balance as of the beginning of the related Collection Period and
      (ii) a fraction, the numerator of which is 360 and the denominator of which
      is
      the actual number of days in the Accrual Period related to such Distribution
      Date. 

     

    Net
      Funds Cap:
      With
      respect to any Distribution Date and any Class of Certificates (other than
      the
      Class X, Class P, Class LT-R and Class R Certificates), a per annum rate equal
      to (a) a fraction, expressed as a percentage, the numerator of which is the
      product of (1) the Optimal Interest Remittance Amount for such Distribution
      Date
      and (2) 12, and the denominator of which is the Pool Balance as of the first
      day
      of the related Collection Period (excluding for this purpose any Mortgage Loans
      for which any Principal Prepayments in full have been deposited into the
      Collection Account and distributed therefrom in accordance with Section 5.02
      during the month prior to such Distribution Date), multiplied by
      (b) a
      fraction, the numerator of which is 30 and the denominator of which is the
      actual number of days in the Accrual Period.

     

    Net
      Liquidation Proceeds:
      With
      respect to any Liquidated Mortgage Loan, the related Liquidation Proceeds net
      of
      (i) the amount necessary to repay any related senior lien mortgage loan on
      the
      related Mortgaged Property, (ii) unreimbursed expenses and (iii) any
      unreimbursed Advances, if any, received and retained in connection with the
      liquidation of such Mortgage Loan.

     

    Net
      Mortgage Rate:
      With
      respect to any Mortgage Loan, the Mortgage Rate thereof, reduced by the
      Servicing Fee Rate for such Mortgage Loan.

     

    Net
      Prepayment Interest Shortfall:
      With
      respect to any Master Servicer Remittance Date, the excess, if any, of any
      Prepayment Interest Shortfalls with respect to the Mortgage Loans for such
      date
      over any amounts paid with respect to such shortfalls by the Servicer pursuant
      to the Servicing Agreement.

     

    
      
        
        

      

      
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    Net
      Swap Payment:
      With
      respect to each Swap Payment Date, the sum of (i) the net payment required
      to be
      made pursuant to the terms of the Swap Agreement, which net payment shall not
      take into account any Swap Termination Payment, and (ii) any unpaid amounts
      due
      on previous Swap Payment Dates and accrued interest thereon as provided in
      the
      Swap Agreement, as calculated by the Swap Counterparty and furnished to the
      Trustee.

     

    Net
      WAC Rate:
      With
      respect to any Distribution Date (and the related Accrual Period), a per annum
      rate equal to the weighted average of the Net Mortgage Rates of the Mortgage
      Loans as of the first day of the related Collection Period (not including for
      this purpose Mortgage Loans for which prepayments in full have been received
      and
      distributed in the month prior to that Distribution Date).

     

    NIM
      Redemption Amount:
      Not
      applicable.

     

    NIM
      Securities:
      Not
      applicable.

     

    NIMS
      Agreement:
      Not
      applicable.

     

    NIMS
      Insurer:
      Not
      applicable.

     

    Non-Book-Entry
      Certificate:
      Any
      Certificate other than a Book-Entry Certificate.

     

    Non-MERS
      Mortgage Loan:
      Any
      Mortgage Loan other than a MERS Mortgage Loan.

     

    Non-permitted
      Foreign Holder:
      As
      defined in Section 3.03(e).

     

    Non-U.S.
      Person:
      Any
      person other than a “United States person” within the meaning of Section
      7701(a)(30) of the Code.

     

    Notional
      Amount:
      Not
      applicable.

     

    Offering
      Document:
      Each of
      the Prospectus and the Private Placement Memorandum.

     

    Officer’s
      Certificate:
      A
      certificate signed by the Chairman of the Board, any Vice Chairman, the
      President, any Vice President or any Assistant Vice President of a Person,
      and
      in each case delivered to the Trustee.

     

    Opinion
      of Counsel:
      A
      written opinion of counsel, reasonably acceptable in form and substance to
      the
      Trustee, and which may be in-house or outside counsel to the Depositor, the
      Master Servicer or the Trustee but which must be Independent outside counsel
      with respect to any such opinion of counsel concerning the transfer of any
      Residual Certificate or concerning certain matters with respect to ERISA, or
      the
      taxation, or the federal income tax status, of each REMIC.

     

    Optimal
      Interest Remittance Amount:
      With
      respect to each Distribution Date, the amount, if any, by which (1) the product
      of (A) (x) the weighted average of the Net Mortgage Rates of the Mortgage Loans,
      as of the first day of the related Collection Period, divided by (y) 12 and
      (B)
      the Pool Balance as of the first day of the related Collection Period (excluding
      for purposes of clauses (A)(x) and (B) any Mortgage Loans for which any
      Principal Prepayments in full have been deposited into the Collection Account
      and distributed therefrom in accordance with Section 5.02 during the month
      prior
      to such Distribution Date), exceeds
      (2) any
      Net Swap Payment or Swap Termination Payment (not due to a Swap Counterparty
      Trigger Event) due to the Swap Counterparty.

     

    
      
        
        

      

      
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    Original
      Value:
      The
      lesser of (a) the Appraised Value of a Mortgaged Property at the time the
      related Mortgage Loan was originated and (b) if the Mortgage Loan was made
      to
      finance the acquisition of the related Mortgaged Property, the purchase price
      paid for the Mortgaged Property by the Mortgagor at the time the related
      Mortgage Loan was originated.

     

    Overcollateralization
      Amount:
      With
      respect to any Distribution Date, the amount, if any, by which (x) the Pool
      Balance for such Distribution Date exceeds (y) the aggregate Class Principal
      Amount of the LIBOR Certificates after giving effect to distributions on such
      Distribution Date.

     

    Overcollateralization
      Deficiency:
      With
      respect to any Distribution Date, the amount, if any, by which (x) the
      Enhancement Target for such Distribution Date exceeds (y) the
      Overcollateralization Amount for such Distribution Date, calculated for this
      purpose after giving effect to the reduction on such Distribution Date of the
      Certificate Principal Amounts of the LIBOR Certificates resulting from the
      distribution of the Principal Distribution Amount on such Distribution Date,
      but
      prior to allocation of any Applied Loss Amount on such Distribution
      Date.

     

    Overcollateralization
      Floor:
      An
      amount equal to $2,657,908.49 (approximately 0.50% of the Cut-off Date
      Balance).

     

    Payahead:
      With
      respect to any Mortgage Loan and any Due Date therefor, any Scheduled Payment
      received by the Servicer during any Collection Period in addition to the
      Scheduled Payment due on such Due Date, intended by the related Mortgagor to
      be
      applied on a subsequent Due Date or Due Dates.

     

    Paying
      Agent:
      Any
      paying agent appointed pursuant to Section 3.08.

     

    PCAOB:
      The
      Public Company Accounting Oversight Board.

     

    Percentage
      Interest:
      With
      respect to any Certificate, its percentage interest in the undivided beneficial
      ownership interest in the Trust Fund evidenced by all Certificates of the same
      Class as such Certificate. With respect to any Certificate other than a Class
      X,
      Class P, Class LT-R or Class R Certificate, the Percentage Interest evidenced
      thereby shall equal the Certificate Principal Amount thereof divided by the
      Class Principal Amount of all Certificates of the same Class. With respect
      to
      the Class X, Class P, Class LT-R and Class R Certificates, the Percentage
      Interest evidenced thereby shall be as specified on the face thereof, or
      otherwise be equal to 100%.

     

    Permitted
      Servicing Amendment:
      Any
      amendment to the Servicing Agreement pursuant to Section 11.03(a)(iii) hereunder
      in connection with any servicing transfer or transfer of any servicing
      rights.

     

    
      
        
        

      

      
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    Person:
      Any
      individual, corporation, partnership, joint venture, association, joint-stock
      company, limited liability company, trust, unincorporated organization or
      government or any agency or political subdivision thereof.

     

    Plan:
      An
      employee benefit plan or other retirement arrangement which is subject to
      Section 406 of ERISA and/or Section 4975 of the Code or any entity whose
      underlying assets include such plan’s or arrangement’s assets by reason of their
      investment in the entity.

     

    Plan
      Asset Regulations:
      The
      Department of Labor regulations set forth in 29 C.F.R. 2510.3-101.

     

    Pool
      Balance:
      As of
      any date of determination, the aggregate of the Scheduled Principal Balances
      of
      all Mortgage Loans.

     

    PPTL
      Purchase Price:
      Not
      applicable.

     

    PPTLS:
      Not
      applicable.

     

    Prepayment
      Interest Shortfall:
      With
      respect to any full or partial Principal Prepayment of a Mortgage Loan, the
      excess, if any, of (i) one full month’s interest at the applicable Mortgage Rate
      (as reduced by the Servicing Fee, as applicable, in the case of Principal
      Prepayments in full) on the outstanding principal balance of such Mortgage
      Loan
      immediately prior to such prepayment over (ii) the amount of interest actually
      received with respect to such Mortgage Loan in connection with such Principal
      Prepayment.

     

    Prepayment
      Period:
      With
      respect to each Distribution Date for Mortgage Loans prepaid in part, the
      calendar month immediately preceding the month in which such Distribution Date
      occurs. With respect to each Distribution Date for Mortgage Loans prepaid in
      full, the period from the sixteenth (16th) day of the preceding calendar month
      through the fifteenth (15th) day of the calendar month in which the Distribution
      Date occurs.

     

    Prepayment
      Premiums:
      Any
      prepayment fees and penalties to be paid by the Mortgagor on a Mortgage
      Loan.

     

    Primary
      Mortgage Insurance Policy:
      Not
      Applicable.

     

    Prime
      Rate:
      The
      prime rate of the United States money center commercial banks as published
      in
The
      Wall Street Journal.

     

    Principal
      Distribution Amount:
      With
      respect to any Distribution Date, an amount equal to the Principal Remittance
      Amount for such date minus
      the
      Aggregate Overcollateralization Release Amount, if any, for such Distribution
      Date.

     

    Principal
      Prepayment:
      Any
      Mortgagor payment of principal (other than a Balloon Payment) or other recovery
      of principal on a Mortgage Loan that is recognized as having been received
      or
      recovered in advance of its scheduled Due Date and applied to reduce the
      principal balance of the Mortgage Loan in accordance with the terms of the
      Mortgage Note or the Servicing Agreement.

     

    
      
        
        

      

      
        38

        
          

        

      

      
        
        

      

    

     

    Principal
      Remittance Amount:
      With
      respect to any Distribution Date, (a) the sum of (i) all principal collected
      (other than Payaheads and Prepayment Premiums) or advanced in respect of
      Scheduled Payments on the Mortgage Loans during the related Collection Period
      by
      the Servicer, the Master Servicer or the Trustee (solely in its capacity as
      successor Master Servicer) (less unreimbursed Advances due to the Master
      Servicer, the Servicer or the Trustee with respect to the Mortgage Loans, to
      the
      extent allocable to principal, and any unreimbursed Servicing Advances not
      reimbursed by a reduction from the Interest Remittance Amount), (ii) all
      Principal Prepayments in full or in part received during the related Prepayment
      Period or Collection Period as applicable, (iii) the outstanding principal
      balance of the Mortgage Loans that were purchased from the Trust Fund by the
      Seller during the related Prepayment Period, (iv) the portion of any
      Substitution Amount paid with respect to any Deleted Mortgage Loan during the
      related Prepayment Period allocable to principal and (v) all Net Liquidation
      Proceeds, Insurance Proceeds, any Subsequent Recovery and other recoveries
      collected with respect to the Mortgage Loans during the related Prepayment
      Period, to the extent allocable to principal, as reduced by (b) to the extent
      not reimbursed from amounts otherwise allocable to interest, any other costs,
      expenses or liabilities reimbursable to the Trustee, the Master Servicer, each
      Custodian and the Servicer to the extent provided in this Agreement, each
      Custodial Agreement and the Servicing Agreement and, with respect to the
      Trustee, to the extent that amounts reduced from the Interest Remittance Amount
      is less than amounts reimbursable to the Trustee pursuant to Section 4.04(b)(i),
      any amounts reimbursable during the related Anniversary Year to the Trustee
      therefrom and not reimbursed by a reduction from the Interest Remittance Amount,
      or otherwise; provided,
      however,
      that
      such reimbursable amounts deducted from the Interest Remittance Amount and
      Principal Remittance Amount may not exceed $200,000 in the aggregate during
      any
      Anniversary Year. In the event that the Trustee incurs reimbursable amounts
      in
      excess of $200,000, it may seek reimbursement for such amounts in subsequent
      Anniversary Years, but in no event shall more than $200,000 be reimbursed to
      the
      Trustee per Anniversary Year. Notwithstanding the foregoing, costs and expenses
      incurred by the Trustee pursuant to Section 6.14(a) in connection with any
      transfer of servicing shall be excluded from the $200,000 per Anniversary Year
      limit on reimbursable amounts. For the avoidance of doubt, (i) the Principal
      Remittance Amount available on each Swap Payment Date for distribution to the
      Swap Account shall be equal to the Principal Remittance Amount on the related
      Distribution Date and (ii) the Principal Remittance Amount for each Distribution
      Date shall be calculated without regard to any distributions to the Swap Account
      on the related Swap Payment Date.

     

    Private
      Placement Memorandum:
      The
      confidential private placement memorandum dated December 21,
      2006,
      relating to the Class B1 and Class B2 Certificates.

     

    Proceeding:
      Any
      suit in equity, action at law or other judicial or administrative
      proceeding.

     

    Proprietary
      Lease:
      Not
      applicable.

     

    Prospectus:
      The
      prospectus supplement dated December 21,
      2006,
      together with the accompanying prospectus dated November 13, 2006, relating
      to the Publicly Offered Certificates.

     

    Publicly
      Offered Certificates:
      The
      Certificates offered under the Prospectus which include the Senior Certificates
      and Class M Certificates.

     

    
      
        
        

      

      
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    Purchase
      Price:
      With
      respect to the purchase of a Mortgage Loan or related REO Property pursuant
      to
      Section 2.05 of this Agreement, an amount equal to the sum of (a) 100% of the
      unpaid principal balance of such Mortgage Loan, (b) accrued interest thereon
      at
      the applicable Mortgage Rate, from the date as to which interest was last paid
      to (but not including) the Due Date in the Collection Period immediately
      preceding the related Distribution Date; (c) any unreimbursed Servicing Advances
      with respect to such Mortgage Loan; and (d) any costs and damages incurred
      by
      the Trust Fund with respect to such Mortgage Loan in connection with any
      violation of any federal, state or local predatory or abusive lending laws
      or
      other similar laws. The Master Servicer, the Servicer (or the Trustee, in its
      capacity as successor Master Servicer, if applicable) shall be reimbursed from
      the Purchase Price for any Mortgage Loan or related REO Property for any
      Advances made or other amounts advanced with respect to such Mortgage Loan
      or
      related REO Property that are reimbursable to the Master Servicer or such
      Servicer under this Agreement or the Servicing Agreement (or to the Trustee
      hereunder in its capacity as successor Master Servicer), together with any
      accrued and unpaid compensation due to the Master Servicer, the Servicer or
      the
      Trustee hereunder or thereunder.

     

    QIB:
      As
      defined in Section 3.03(c).

     

    Qualified
      GIC:
      A
      guaranteed investment contract or surety bond providing for the investment
      of
      funds in the Collection Account or the Certificate Account and insuring a
      minimum, fixed or floating rate of return on investments of such funds, which
      contract or surety bond shall:

     

    (i) be
      an
      obligation of an insurance company or other corporation whose long-term debt
      is
      rated by each Rating Agency in one of its two highest rating categories or,
      if
      such insurance company has no long-term debt, whose claims paying ability is
      rated by each Rating Agency in one of its two highest rating categories, and
      whose short-term debt is rated by each Rating Agency in its highest rating
      category;

     

    (ii) provide
      that the Trustee may exercise all of the rights under such contract or surety
      bond without the necessity of taking any action by any other
      Person;

     

    (iii) provide
      that if at any time the then current credit standing of the obligor under such
      guaranteed investment contract is such that continued investment pursuant to
      such contract of funds would result in a downgrading of any rating of the
      Certificates, the Trustee shall terminate such contract without penalty and
      be
      entitled to the return of all funds previously invested thereunder, together
      with accrued interest thereon at the interest rate provided under such contract
      to the date of delivery of such funds to the Trustee;

     

    (iv) provide
      that the Trustee’s interest therein shall be transferable to any successor
      trustee hereunder; and

     

    (v) provide
      that the funds reinvested thereunder and accrued interest thereon be returnable
      to the Collection Account or the Certificate Account, as the case may be, not
      later than the Business Day prior to any Distribution Date.

     

    
      
        
        

      

      
        40

        
          

        

      

      
        
        

      

    

     

    Qualified
      Insurer:
      An
      insurance company duly qualified as such under the laws of the states in which
      the related Mortgaged Properties are located, duly authorized and licensed
      in
      such states to transact the applicable insurance business and to write the
      insurance provided and whose claims paying ability is rated by each Rating
      Agency in its highest rating category or whose selection as an insurer will
      not
      adversely affect the ratings of the Certificates.

     

    Qualifying
      Substitute Mortgage Loan:
      In the
      case of a Mortgage Loan substituted for a Deleted Mortgage Loan pursuant to
      the
      terms of this Agreement, a Mortgage Loan that, on the date of such substitution,
      (i) has an outstanding Scheduled Principal Balance (or in the case of a
      substitution of more than one mortgage loan for a Deleted Mortgage Loan, an
      aggregate Scheduled Principal Balance), after application of all Scheduled
      Payments due during or prior to the month of substitution, not in excess of,
      and
      not more than 5% less than, the outstanding Scheduled Principal Balance of
      the
      Deleted Mortgage Loan as of the Due Date in the calendar month during which
      the
      substitution occurs, (ii) has a Mortgage Rate not less than the Mortgage Rate
      on
      the Deleted Mortgage Loan, (iii) if applicable, has a maximum Mortgage Rate
      not
      less than the maximum Mortgage Rate on the Deleted Mortgage Loan, (iv) if
      applicable, has a minimum Mortgage Rate not less than the minimum Mortgage
      Rate
      of the Deleted Mortgage Loan, (v) if applicable, has a gross margin equal to
      or
      greater than the gross margin of the Deleted Mortgage Loan, (vi) if applicable,
      has a next adjustment date not later than the next adjustment date on the
      Deleted Mortgage Loan, (vii) has the same Due Date as the Deleted Mortgage
      Loan,
      (viii) has a remaining stated term to maturity not more than 18 months longer
      and not more than 18 months shorter than the remaining stated term to maturity
      of the related Deleted Mortgage Loan; provided
      that
      in
      no case shall such substitute Mortgage Loan have a maturity date later than
      the
      Final Scheduled Distribution Date, (ix) is current as of the date of
      substitution, (x) has a Combined Loan-to-Value Ratio as of the date of
      substitution equal to or lower than the Combined Loan-to-Value Ratio of the
      Deleted Mortgage Loan as of such date, (xi) has been underwritten in accordance
      with the same underwriting criteria and guidelines as the Deleted Mortgage
      Loan,
      (xii) has a risk grading determined by the Seller at least equal to the risk
      grading assigned on the Deleted Mortgage Loan, (xiii) is secured by the same
      property type as the Deleted Mortgage Loan, (xiv) conforms to each
      representation and warranty applicable to the Deleted Mortgage Loan made in
      the
      Mortgage Loan Sale Agreement, (xv) has the same or higher lien position as
      the
      Deleted Mortgage Loan, and (xvi) contains provisions covering the payment of
      Prepayment Premium by the Mortgagor for early prepayment of the Mortgage Loan
      at
      least as favorable as the Deleted Mortgage Loan. In the event that one or more
      mortgage loans are substituted for one or more Deleted Mortgage Loans, the
      amounts described in clause (i) hereof shall be determined on the basis of
      aggregate Scheduled Principal Balances, the Mortgage Rates described in clause
      (ii) hereof shall be determined on the basis of weighted average Mortgage Rates,
      the risk gradings described in clause (xii) hereof shall be satisfied as to
      each
      such mortgage loan, the terms described in clause (viii) hereof shall be
      determined on the basis of a weighted average remaining term to maturity;
provided
      that the
      stated maturity date of any Qualifying Substitute Mortgage Loan shall not be
      later than the Final Scheduled Distribution Date, the Combined Loan-to-Value
      Ratios described in clause (x) hereof shall be satisfied as to each such
      mortgage loan and, except to the extent otherwise provided in this sentence,
      the
      representations and warranties described in clause (xiv) hereof must be
      satisfied as to each Qualifying Substitute Mortgage Loan or in the aggregate,
      as
      the case may be.

     

    Rating
      Agency:
      Each of
      Moody’s and S&P.

     

    
      
        
        

      

      
        41

        
          

        

      

      
        
        

      

    

     

    Realized
      Loss:
      With
      respect to each Liquidated Mortgage Loan, an amount equal to (i) the unpaid
      principal balance of such Mortgage Loan as of the date of liquidation, minus
      (ii) Liquidation Proceeds received, to the extent allocable to principal, net
      of
      amounts that are reimbursable therefrom to the Master Servicer or the Servicer
      with respect to such Mortgage Loan (other than Advances of principal) including
      expenses of liquidation. In determining whether a Realized Loss is a Realized
      Loss of principal, Liquidation Proceeds shall be allocated, first, to payment
      of
      expenses related to such Liquidated Mortgage Loan, then to accrued unpaid
      interest and finally to reduce the principal balance of the Mortgage
      Loan.

     

    Recognition
      Agreement:
      Not
      applicable.

     

    Record
      Date:
      With
      respect to any Class of Certificates other than the Class X, Class P, Class
      LT-R
      and Class R Certificates and any Distribution Date, the close of business on
      the
      Business Day immediately preceding such Distribution Date. With respect to
      any
      Class of Definitive Certificates and any Distribution Date, the last Business
      Day of the month immediately preceding the month in which the Distribution
      Date
      occurs (or, in the case of the first Distribution Date, the Closing
      Date).

     

    Regulation
      AB:
      Subpart
      229.1100 - Asset Backed Securities (Regulation AB), 17 C.F.R.
      Sec.Sec.229.1100-229.1123, as such may be amended from time to time, and subject
      to such clarification and interpretation as have been provided by the Commission
      in the adopting release (Asset-Backed Securities, Securities Act Release No.
      33-8518, 70 Fed. Reg. 1,506, 1,531 (Jan. 7, 2005)) or by the staff of the
      Commission, or as may be provided by the Commission or its staff from time
      to
      time.

     

    Regulation
      S:
      Regulation S promulgated under the Securities Act or any successor provision
      thereto, in each case as the same may be amended from time to time; and all
      references to any rule, section or subsection of, or definition or term
      contained in, Regulation S means such rule, section, subsection, definition
      or
      term, as the case may be, or any successor thereto, in each case as the same
      may
      be amended from time to time.

     

    Regulation
      S Global Security:
      The
      meaning specified in Section 3.01(d).

     

    Released
      Mortgage Loan:
      As of
      any transfer date as set forth in the Servicing Agreement, any Mortgage Loan
      other than a Covered Mortgage Loan that was delinquent in payment for a period
      of time equal to the later to occur of (i) 210 days or more or (ii) 30 days
      or
      more after such Mortgage Loan became a Charged-off Loan, in each case as of
      the
      last calendar day of the month immediately proceeding the month in which such
      transfer date occurs, without giving effect to any grace period permitted by
      the
      related Mortgage Note, and for which foreclosure proceedings have not been
      initiated.

     

    Released
      Mortgage Transferee:
      The
      Master Servicer.

     

    Relevant
      Servicing Criteria:
      The
      Servicing Criteria applicable to each party, as set forth on Exhibit T attached
      hereto. Multiple parties can have responsibility for the same Relevant Servicing
      Criteria. With respect to a Servicing Function Participant engaged by the Master
      Servicer, the Paying Agent, the Trustee, the Credit Risk Manager, a Custodian
      or
      the Servicer, the term “Relevant Servicing Criteria” may refer to a portion of
      the Relevant Servicing Criteria applicable to such parties.

     

    
      
        
        

      

      
        42

        
          

        

      

      
        
        

      

    

     

    Relief
      Act Reduction:
      With
      respect to any Mortgage Loan as to which there has been a reduction in the
      amount of interest collectible thereon as a result of application of the Civil
      Relief Act, any amount by which interest collectible on such Mortgage Loan
      for
      the Due Date in the related Collection Period is less than interest accrued
      thereon for the applicable one-month period at the Mortgage Rate without giving
      effect to such reduction.

     

    REMIC:
      Each
      pool of assets in the Trust Fund designated as a REMIC pursuant to the
      Preliminary Statement.

     

    REMIC
      1:
      As
      described in the Preliminary Statement.

     

    REMIC
      2:
      As
      described in the Preliminary Statement.

     

    REMIC
      3:
      As
      described in the Preliminary Statement.

     

    REMIC
      4:
      As
      described in the Preliminary Statement.

     

    REMIC 3
      Net Funds Cap:
      For any
      Distribution Date (and the related Accrual Period) and any Class of
      Certificates, an amount equal to (i) the weighted average of the interest rates
      on the REMIC 3 Regular Interests (other than the LT3-SIO Interest),
      weighted in proportion to their Class Principal Amounts as of the beginning
      of
      the related Accrual Period, multiplied by (ii) the quotient of (a) 30 divided
      by
      (b) the actual number of days in the Accrual Period.

     

    REMIC
      Provisions:
      The
      provisions of the federal income tax law relating to real estate mortgage
      investment conduits, which appear at sections 860A through 860G of Subchapter
      M
      of Chapter 1 of the Code, and related provisions, and regulations, including
      proposed regulations and rulings, and administrative pronouncements promulgated
      thereunder, as the foregoing may be in effect from time to time.

     

    REMIC
      Swap Rate:
      For
      each Distribution Date (and the related Accrual Period), a per annum rate equal
      to the product of: (i) the “Rate of Payment (%)” under the Swap Agreement for
      such Distribution Date, as set forth in Annex C to the Prospectus, (ii) 2,
      and
      (iii) the quotient of (a) the actual number of days in the related Accrual
      Period divided by (b) 30.

     

    REO
      Property:
      A
      Mortgaged Property acquired by the Trust Fund through foreclosure or
      deed-in-lieu of foreclosure in connection with a defaulted Mortgage Loan or
      otherwise treated as having been acquired pursuant to the REMIC
      Provisions.

     

    Reportable
      Event:
      As
      defined in Section 6.20(f)(i).

     

    Reporting
      Servicer:
      As
      defined in Section 6.20(e)(i).

     

    Required
      Reserve Fund Deposit:
      With
      respect to any Distribution Date on which the Net Excess Spread is less than
      0.25%, the amount, if any by which (a) the product of 1.00% and the Pool Balance
      for such date exceeds (b) the amount on deposit in the Basis Risk Reserve Fund
      immediately prior to such date. With respect to any Distribution Date on which
      the Net Excess Spread is equal to or greater than 0.25%, the amount, if any,
      by
      which (i) $1,000 exceeds the amount on deposit in the Basis Risk Reserve Fund
      immediately prior to such date; provided,
      however,
      that on
      any Distribution Date on which the Class Principal Amount of each Class of
      LIBOR
      Certificates has been reduced to zero, the Required Reserve Fund Deposit shall
      be zero.

     

    
      
        
        

      

      
        43

        
          

        

      

      
        
        

      

    

     

    Residual
      Certificate:
      Any
      Class LT-R or Class R Certificate.

     

    Responsible
      Officer:
      When
      used with respect to the Trustee, any vice president, assistant vice president,
      the secretary, any assistant secretary, or any officer, working in its Corporate
      Trust Office and having responsibility for the administration of this Agreement,
      and any other officer to whom a matter arising under this Agreement may be
      referred.

     

    Restricted
      Certificate:
      Any
      Class B Certificate and any Class P, Class X, Class LT-R or Class R
      Certificate.

     

    Restricted
      Global Security:
      As
      defined in Section 3.01(c).

     

    Rolling
      Three Month Delinquency Rate:
      With
      respect to any Distribution Date, the average of the Delinquency Rates for
      each
      of the three (or one and two, in the case of the first and second Distribution
      Dates, respectively) immediately preceding calendar months.

     

    Rule
      144A:
      Rule
      144A under the Securities Act.

     

    Rules:
      As
      defined in Section 6.20(c).

     

    S&P:
      Standard & Poor’s Ratings Services, a division of The McGraw Hill Companies,
      Inc., or any successor in interest. 

     

    Sarbanes-Oxley
      Act:
      The
      Sarbanes-Oxley Act of 2002 and the rules and regulations of the Commission
      promulgated thereunder (including any interpretations thereof by the
      Commission’s staff).

     

    Sarbanes-Oxley
      Certification:
      A
      written certification covering the activities of all Servicing Function
      Participants and signed by an officer of the Exchange Act Signing Party that
      complies with Section 302 of the Sarbanes-Oxley Act, as amended from time to
      time.

     

    Scheduled
      Payment:
      Each
      scheduled payment of principal and interest (or of interest only, if applicable)
      to be paid by the Mortgagor on a Mortgage Loan, as reduced (except where
      otherwise specified herein) by the amount of any related Debt Service Reduction,
      excluding all amounts of principal and interest that were due on or before
      the
      Cut-off Date whenever received) and, in the case of an REO Property, an amount
      equivalent to the Scheduled Payment that would have been due on the related
      Mortgage Loan if such Mortgage Loan had remained in existence.

     

    Scheduled
      Principal Balance:
      With
      respect to (i) any Mortgage Loan as of any Distribution Date, the principal
      balance of such Mortgage Loan at the close of business on the Cut-off Date
      after
      giving effect to principal payments due on or before the Cut-off Date, whether
      or not received, less an amount equal to principal payments due after the
      Cut-off Date, and on or before the Due Date in the related Collection Period,
      whether or not received from the Mortgagor or advanced by the Servicer or the
      Master Servicer, and all amounts allocable to unscheduled principal payments
      (including Principal Prepayments, Liquidation Proceeds, Insurance Proceeds
      and
      condemnation proceeds, in each case to the extent identified and applied prior
      to or during the related Prepayment Period) and (ii) any REO Property as of
      any
      Distribution Date, the Scheduled Principal Balance of the related Mortgage
      Loan
      on the Due Date immediately preceding the date of acquisition of such REO
      Property by or on behalf of the Trustee (reduced by any amount applied as a
      reduction of principal on the Mortgage Loan). With respect to any Mortgage
      Loan
      and the Cut-off Date, the principal balance of such Mortgage Loan as specified
      in the Mortgage Loan Schedule. The Scheduled Principal Balance of any Liquidated
      Mortgage Loan shall be zero.

     

    
      
        
        

      

      
        44

        
          

        

      

      
        
        

      

    

     

    Section
      7.01(c) Purchase Event:
      The
      purchase of all the Lower Tier REMIC 1 Uncertificated Regular
      Interests.

     

    Securities
      Act:
      The
      Securities Act of 1933, as amended.

     

    Security
      Agreement:
      Not
      applicable.

     

    Seller:
      Lehman
      Brothers Holdings Inc., or any successor in interest.

     

    Seller
      Remittance Amount:
      With
      respect to the Servicer, the meaning assigned to such term in the Servicing
      Agreement.

     

    Senior
      Certificate:
      The
      Class A Certificate.

     

    Senior
      Enhancement Percentage:
      With
      respect to any Distribution Date, the fraction, expressed as a percentage,
      the
      numerator of which is the sum of the aggregate Class Principal Amount of the
      Subordinate Certificates and the Overcollateralization Amount (which amount,
      for
      purposes of this definition only, shall not be less than zero and assuming
      for
      purposes of this definition that the Principal Distribution Amount has been
      distributed on such Distribution Date and no Trigger Event has occurred) and
      the
      denominator of which is the Pool Balance for such Distribution Date, in each
      case after giving effect to distributions on such Distribution
      Date.

     

    Senior
      Principal Distribution Amount:
      With
      respect to any Distribution Date on or after the Stepdown Date and as long
      as a
      Trigger Event is not in effect with respect to such Distribution Date, the
      lesser of (x) the Principal Distribution Amount and (y) the amount, if any,
      by
      which (A) the Class Principal Amount of the Senior Certificates immediately
      prior to that Distribution Date exceeds (B) the Senior Target Amount for such
      Distribution Date.

     

    Senior
      Priority:
      Not
      applicable.

     

    Senior
      Target Amount:
      With
      respect to any Distribution Date, an amount equal to the lesser of (a) the
      product of (i) 38.30% and (ii) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period and (b) the
      amount, if any, by which (i) the Pool Balance for such Distribution Date
      determined as of the last day of the related Collection Period exceeds (ii)
      the
      Overcollateralization Floor.

     

    Servicer:
      Aurora
      and any of its successors in interest.

     

    
      
        
        

      

      
        45

        
          

        

      

      
        
        

      

    

     

    Servicer
      Remittance Date:
      The day
      in each calendar month on which the Servicer is required to remit payments
      to
      the Collection Account, as specified in the Servicing Agreement, which is the
      18th
      day of
      each calendar month (or, if such 18th
      day is
      not a Business Day, the next succeeding Business Day, as specified in the
      Servicing Agreement).

     

    Service(s)(ing):
      In
      accordance with Regulation AB, the act of managing or collecting payments on
      the
      Mortgage Loans or any other assets of the Trust Fund by an entity that meets
      the
      definition of “servicer’ set forth in Item 1101 of Regulation AB. For
      clarification purposes, any uncapitalized occurrence of this term shall have
      the
      meaning commonly understood by participants in the residential mortgage-backed
      securitization market.

     

    Servicing
      Advances:
      All
      customary, reasonable and necessary “out of pocket” costs and expenses other
      than Advances (including reasonable attorneys’ fees and disbursements) incurred
      in the performance by the Servicer of its servicing obligations, including,
      but
      not limited to, the cost of (a) satisfying the outstanding amount of a senior
      mortgage lien on the Mortgaged Property in order to prevent a foreclosure,
      (b)
      the preservation, inspection, restoration and protection of the Mortgaged
      Property, (c) any enforcement or administrative or judicial proceedings,
      including foreclosures, (d) the management and liquidation of the Mortgaged
      Property if the Mortgaged Property is acquired in satisfaction of the Mortgage,
      (e) taxes, assessments, water rates, sewer rents and other charges which are
      or
      may become a lien upon the Mortgaged Property, any insurance premiums related
      to
      insurance on the Mortgaged Property and (f) any losses sustained by the Servicer
      with respect to the liquidation of the Mortgaged Property.

     

    Servicing
      Agreement:
      The
      servicing agreement identified in Exhibit E hereto among the Seller, the Master
      Servicer and the Servicer, and any other servicing agreement or securitization
      subservicing agreement entered into between a successor servicer and the Seller
      pursuant to the terms of this Agreement and the Servicing
      Agreement.

     

    Servicing
      Criteria:
      The
      criteria set forth in paragraph (d) of Item 1122 of Regulation AB.

     

    Servicing
      Fee:
      As to
      any Distribution Date and each Mortgage Loan, an amount equal to the product
      of
      (a) one-twelfth of the Servicing Fee Rate and (b) the outstanding principal
      balance of such Mortgage Loan as of the first day of the related Collection
      Period. No Servicing Fee will accrue with respect to any Charged-off Loan.
      

     

    Servicing
      Fee Rate:
      With
      respect to each Mortgage Loan, the rate specified in the Servicing Agreement
      as
“General Servicing Fee Rate.”

     

    Servicing
      Function Participant:
      Any
      Subservicer, Subcontractor or any other Person, other than the Servicer, a
      Custodian, the Master Servicer, the Paying Agent and the Trustee, that is
      participating in the servicing function within the meaning of Regulation AB,
      unless such Person’s activities relate only to 5% or less of the Mortgage
      Loans.

     

    Sponsor:
      Lehman
      Brothers Holdings Inc., or any successor in interest.

     

    Startup
      Day:
      The day
      designated as such pursuant to Section 10.01(b) hereof.

     

    
      
        
        

      

      
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    Stepdown
      Date:
      The
      earlier of (i) the first Distribution Date following the Distribution Date
      on
      which the Class Principal Amount of the Senior Certificates has been reduced
      to
      zero or (ii) the later of (x) the Distribution Date in January 2010 and (y)
      the
      first Distribution Date on which the Senior Enhancement Percentage (calculated
      for this purpose after giving effect to payments or other recoveries in respect
      of the Mortgage Loans during the related Collection Period but before giving
      effect to distribution on any Certificates on such Distribution Date) is greater
      than or equal to 61.70%.

     

    Subcontractor:
      Any
      vendor, subcontractor or other Person that is not responsible for the overall
      servicing (as “servicing” is commonly understood by participants in the
      mortgage-backed securities market) of the Mortgage Loans but performs one or
      more discrete functions identified in Item 1122(d) of Regulation AB with respect
      to the Mortgage Loans under the direction or authority of the Trustee, the
      Master Servicer, a Custodian, the Servicer or the Credit Risk
      Manager.

     

    Subordinate
      Certificate:
      Any
      Class M Certificate or Class B Certificate.

     

    Subordinate
      Priority:
      To the
      Class M1, Class M2, Class M3, Class M4, Class M5, Class M6, Class M7, Class
      M8,
      Class M9, Class B1 and Class B2 Certificates, sequentially, in that
      order.

     

    Subsequent
      Recovery:
      Any
      amount recovered by the Servicer or the Master Servicer with respect to a
      Liquidated Mortgage Loan (other than a Released Mortgage Loan) with respect
      to
      which a Realized Loss was incurred after the liquidation or disposition of
      such
      Mortgage Loan.

     

    Subservicer:
      Any
      Person that (i) is considered to be a Servicing Function Participant, (ii)
      services Mortgage Loans on behalf of the Servicer or Additional Servicer, and
      (iii) is responsible for the performance (whether directly or through
      subservicers or Subcontractors) of Servicing functions required to be performed
      under this Agreement, the Servicing Agreement or any subservicing agreement
      that
      are identified in Item 1122(d) of Regulation AB.

     

    Substitution
      Amount:
      The
      amount, if any, by which the Scheduled Principal Balance of a Deleted Mortgage
      Loan exceeds the Scheduled Principal Balance of the related Qualifying
      Substitute Mortgage Loan, or aggregate Scheduled Principal Balance, if
      applicable, plus
      unpaid
      interest thereon; any related unpaid Advances or Servicing Advances or unpaid
      Servicing Fees; and the amount of any costs and damages incurred by the Trust
      Fund associated with a violation of any applicable federal, state or local
      predatory or abusive lending law in connection with the origination of such
      Deleted Mortgage Loan.

     

    Supplemental
      Interest Trust:
      The
      corpus of a trust created pursuant to Section 5.07 of this Agreement and
      designated as the “Supplemental Interest Trust,” consisting of the Swap
      Agreement, the Swap Account, the Collateral Account, the right to receive the
      Class X Distributable Amount as provided in Section 5.02(d)(vii), the Class
      I
      interest in REMIC 4 and the right to receive Class I
      Shortfalls.

     

    Swap
      Account:
      The
      account created pursuant to Section 5.07(a) of this Agreement.

     

    
      
        
        

      

      
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    Swap
      Agreement:
      The
      interest rate swap agreement dated as of December 28, 2006, entered into by
      the Supplemental Interest Trust and the Swap Counterparty, which agreement
      provides for, among other things, a Net Swap Payment to be paid pursuant to
      the
      conditions provided therein, together with any schedules, confirmations, credit
      support annex or other agreements relating thereto, attached hereto as Exhibit
      P.

     

    Swap
      Amount:
      With
      respect to each Distribution Date and the related Swap Payment Date, the sum
      of
      any Net Swap Payment and any Swap Termination Payment deposited into the Swap
      Account, and any investment earnings thereon.

     

    Swap
      Counterparty:
      The
      counterparty to the Supplemental Interest Trust under the Swap Agreement, and
      any successor in interest or assigns. Initially, the Swap Counterparty shall
      be
      Wachovia Bank, National Association.

     

    Swap
      Counterparty Trigger Event:
      A Swap
      Counterparty Trigger Event shall have occurred if any of a Swap Default with
      respect to which the Swap Counterparty is a Defaulting Party, a Termination
      Event (other than an Illegality or Tax Event, as such terms are defined in
      the
      Swap Agreement) with respect to which the Swap Counterparty is the sole Affected
      Party or an Additional Termination Event with respect to which the Swap
      Counterparty is the sole Affected Party has occurred.

     

    Swap
      Default:
      Any of
      the circumstances constituting an “Event of Default” under the Swap
      Agreement.

     

    Swap
      LIBOR:
      With
      respect to any Distribution Date and the related Swap Payment Date (and the
      Accrual Period relating to such Distribution Date), the product of (i) the
      Floating Rate Option (as defined in the Swap Agreement) for the related Swap
      Payment Date, (ii) two, and (iii) the quotient of (a) the actual number of
      days
      in the Accrual Period for the LIBOR Certificates and (b) 30, as calculated
      by
      the Swap Counterparty and furnished to the Trustee.

     

    Swap
      Payment Date:
      For so
      long as the Swap Agreement is in effect or any amounts remain unpaid thereunder,
      the Business Day immediately preceding each Distribution Date.

     

    Swap
      Replacement Receipts:
      As
      defined in Section 5.09(a).

     

    Swap
      Replacement Receipts Account:
      As
      defined in Section 5.09(a).

     

    Swap
      Termination Payment:
      Upon
      the designation of an “Early Termination Date” as defined in the Swap Agreement,
      the payment required to be made by the Supplemental Interest Trust to the Swap
      Counterparty, or by the Swap Counterparty to the Supplemental Interest Trust,
      as
      applicable, pursuant to the terms of the Swap Agreement, and any unpaid amounts
      due on previous Swap Payment Dates and accrued interest thereon as provided
      in
      the Swap Agreement, as calculated by the Swap Counterparty and furnished to
      the
      Trustee.

     

    Swap
      Termination Receipts:
      As
      defined in Section 5.09(a).

     

    Swap
      Termination Receipts Account:
      As
      defined in Section 5.09(a).

     

    
      
        
        

      

      
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    Target
      Amount:
      With
      respect to any Distribution Date, an amount equal to (i) the Pool Balance as
      of
      such Distribution Date minus
      (ii) the
      excess, if any, of (x) the Enhancement Target for such Distribution Date over
      (y) the aggregate Class Principal Amount of the Class B Certificates for such
      Distribution Date, calculated for this purpose after giving effect to
      distributions of the Principal Distribution Amount, but prior to allocation
      of
      any Applied Loss Amount on such Distribution Date.

     

    Tax
      Matters Person:
      The
“tax matters person” as specified in the REMIC Provisions.

     

    Telerate
      Page 3750:
      The
      display currently so designated as “Page 3750” on the Moneyline Telerate Service
      (or such other page selected by the Trustee as may replace Page 3750 on that
      service for the purpose of displaying daily comparable rates on
      prices).

     

    Termination
      Event:
      As
      defined in the Swap Agreement.

     

    Termination
      Price:
      As
      defined in Section 7.01.

     

    Title
      Insurance Policy:
      A title
      insurance policy maintained with respect to a Mortgage Loan.

     

    Total
      Distribution Amount:
      With
      respect to any Distribution Date, the sum of (i) the Interest Remittance Amount
      for such date; (ii) the Principal Remittance Amount for such date; and (iii)
      all
      Prepayment Premiums collected during the related Prepayment Period.

     

    Transfer
      Agreements:
      Not
      applicable.

     

    Transferor:
      Not
      applicable.

     

    Trigger
      Event:
      A
      Trigger Event shall have occurred with respect to any Distribution Date if
      either a Delinquency Event or a Cumulative Loss Trigger Event is in effect
      for
      such Distribution Date.

     

    Trust
      Fund:
      The
      corpus of the Structured Asset Securities Corporation Mortgage Loan Trust
      2006-S4 created pursuant to this Agreement, consisting of the Mortgage Loans,
      the Mortgage Loan Sale Agreement and the Servicing Agreement, such amounts
      as
      shall from time to time be held in the Collection Account, the Certificate
      Account, the Custodial Account and any Escrow Account, the Swap Termination
      Receipts Account, the Swap Replacement Receipts Account, the Basis Risk Reserve
      Fund, the Insurance Policies, any REO Property and the other items referred
      to
      in, and conveyed to the Trustee under, Section 2.01(a).

     

    Trust
      Fund Termination Event:
      As
      defined in Section 7.01(a).

     

    Trustee:
      Citibank, N.A., not in its individual capacity but solely as Trustee, or any
      successor in interest, or if any successor trustee shall be appointed as herein
      provided, then such successor in interest or successor trustee, as the case
      may
      be.

     

    UCC:
      The
      Uniform Commercial Code as in effect in any applicable jurisdiction from time
      to
      time.

     

    
      
        
        

      

      
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    Underwriter:
      Lehman
      Brothers Inc.

     

    Underwriter’s
      Exemption:
      Prohibited Transaction Exemption 2002-41, 67 Fed. Reg. 54487 (2002), as amended
      (or any successor thereto), or any substantially similar administrative
      exemption granted by the U.S. Department of Labor.

     

    Uniform
      Commercial Code:
      The
      Uniform Commercial Code as in effect in any applicable jurisdiction from time
      to
      time.

     

    Unpaid
      Basis Risk Shortfall:
      With
      respect to any Distribution Date and any LIBOR Certificate, the aggregate of
      all
      Basis Risk Shortfalls with respect to such Certificate remaining unpaid from
      all
      previous Distribution Dates, plus interest accrued thereon at the applicable
      Certificate Interest Rate (calculated without giving effect to the Net Funds
      Cap).

     

    Upper
      Tier REMIC:
      REMIC 4.

     

    Voting
      Interests:
      The
      portion of the voting rights of all the Certificates that is allocated to any
      Certificate for purposes of the voting provisions of this Agreement. At all
      times during the term of this Agreement, 97.00% of all Voting Interests shall
      be
      allocated to the LIBOR Certificates. Voting Interests shall be allocated among
      the Classes of LIBOR Certificates (and among the Certificates within each such
      Class) in proportion to their Class Principal Amounts (or Certificate Principal
      Amounts). 1% of all Voting Interests shall be allocated to each of the Class
      P,
      Class R and Class X Certificates while they remain outstanding. Voting Interests
      shall be allocated among the Classes of Certificates (and among the Certificates
      within each such Class) in proportion to their Class Principal Amounts (or
      Certificate Principal Amounts) or Percentage Interests. In the case of the
      purchase by the Master Servicer of the Lower Tier REMIC 1 Uncertificated Regular
      Interests pursuant to a Section 7.01(c) Purchase Event, the LTURI-holder shall
      be allocated 100% of the Voting Interests and upon such purchase any provision
      in this Agreement which requires a vote by, a direction or notice given by,
      an
      action taken by, a request in writing by or the consent of, any percentage
      of
      the Holders of the Certificates or any Class of Certificates may be exercised
      by
      the LTURI-holder.

     

    
      	 	
              Section
                1.02 

            	
              Calculations
                Respecting Mortgage Loans. 

            


    

     

    Calculations
      required to be made pursuant to this Agreement with respect to any Mortgage
      Loan
      in the Trust Fund shall be made based upon current information as to the terms
      of the Mortgage Loans and reports of payments received from the Mortgagor on
      such Mortgage Loans and payments to be made to the Trustee as supplied to the
      Trustee by the Master Servicer
      or the
      Swap Counterparty. The Trustee shall not be required to recompute, verify or
      recalculate the information supplied to it by the Master Servicer, the Swap
      Counterparty, the Servicer or the Credit Risk Manager.

     

    
      	 	
              Section
                1.03 

            	
              Calculations
                Respecting Accrued Interest. 

            


    

     

    Accrued
      interest, if any, on any Certificate other than any Class X, Class P, Class
      LT-R
      or Class R Certificate shall be calculated based upon a 360-day year and the
      actual number of days in each Accrual Period. Accrued interest, if any, on
      any
      Lower Tier Interest shall be calculated based upon a 360-day year consisting
      of
      twelve 30-day months, and each Accrual Period shall be deemed to have 30
      days.

     

    
      
        
        

      

      
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    ARTICLE
      II

     

    DECLARATION
      OF TRUST;

    ISSUANCE
      OF CERTIFICATES

     

    
      	 	
              Section
                2.01 

            	
              Creation
                and Declaration of Trust Fund; Conveyance of Mortgage
                Loans.

            


    

     

    (a) Concurrently
      with the execution and delivery of this Agreement, the Depositor does hereby
      transfer, assign, set over, deposit with and otherwise convey to the Trustee,
      without recourse, subject to Sections 2.02, 2.04, 2.05 and 2.06, in trust,
      all
      the right, title and interest of the Depositor in and to the Mortgage Loans.
      Such conveyance includes, without limitation, the right to all payments of
      principal and interest received on or with respect to the Mortgage Loans on
      and
      after the Cut-off Date (other than payments of principal and interest due on
      or
      before such date), and all such payments due after such date but received prior
      to such date and intended by the related Mortgagors to be applied after such
      date together with all of the Depositor’s right, title and interest in and to
      the Collection Account and all amounts from time to time credited to and the
      proceeds of the Collection Account, the Certificate Account and all amounts
      from
      time to time credited to and the proceeds of the Certificate Account (exclusive
      of investment earnings thereon), the Custodial Accounts and all amounts from
      time to time credited to and the proceeds of the Custodial Accounts, any Escrow
      Account established pursuant to Section 9.06 and any Basis Risk Reserve Fund
      established pursuant to Section 5.06 and all amounts from time to time credited
      to and the proceeds of each such account, any REO Property and the proceeds
      thereof, the Depositor’s rights under any Insurance Policies related to the
      Mortgage Loans, the Depositor’s security interest in any collateral pledged to
      secure the Mortgage Loans, including the Mortgaged Properties and any Additional
      Collateral, and any proceeds of the foregoing, to have and to hold, in trust;
      and the Trustee declares that, subject to the review provided for in Section
      2.02, it has received and shall hold the Trust Fund, as trustee, in trust,
      for
      the benefit and use of the Holders of the Certificates and for the purposes
      and
      subject to the terms and conditions set forth in this Agreement, and,
      concurrently with such receipt, has caused to be executed, authenticated and
      delivered to or upon the order of the Depositor, in exchange for the Trust
      Fund,
      Certificates in the authorized denominations evidencing the entire ownership
      of
      the Trust Fund.

     

    Concurrently
      with the execution of this Agreement, the Swap Agreement shall be delivered
      to
      the Trustee. In connection therewith, the Depositor hereby directs the Trustee
      (solely in its capacity as such) and the Trustee is hereby authorized to execute
      and deliver the Swap Agreement on behalf of the Supplemental Interest Trust
      and
      for the benefit of the Certificateholders. The Seller, the Master Servicer,
      the
      Depositor, the Servicer and the Certificateholders (by their acceptance of
      such
      Certificates) acknowledge and agree that the Trustee is executing and delivering
      the Swap Agreement solely in its capacity as Trustee of the Supplemental
      Interest Trust and not in its individual capacity. The Depositor hereby
      authorizes and directs the Trustee to enter into the Swap Agreement and
      authorizes it to represent in the Swap Agreement that it is not required by
      any
      applicable law of any relevant jurisdiction to make any deduction or withholding
      for or on account of any tax from any Net Swap Payment. Furthermore,
      the Depositor hereby authorizes the Trustee, in its capacity as trustee on
      behalf of the Supplement Interest Trust to perform all of the obligations of
      the
      Supplemental Interest Trust under the Swap Agreement, including to: (x) take
      direction from the Depositor as specified in the Swap Agreement, (y) accept
      any
“Firm Offers” as specified in the Swap Agreement and (z) authorize the payment
      to Lehman Brothers Holding Inc. of the "Floating Rate Payer Upfront Payment"
      specified in the Swap Agreement. The Trustee shall have no duty or
      responsibility to enter into any other interest rate swap agreement upon the
      expiration or termination of the Swap Agreement, other than as provided in
      Section 5.09(a).

     

    
      
        
        

      

      
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    Concurrently
      with the execution and delivery of this Agreement, the Depositor does hereby
      assign to the Trustee all of its rights and interest under the Mortgage Loan
      Sale Agreement, including all rights of the Seller under the Servicing Agreement
      but only to the extent assigned under the Mortgage Loan Sale Agreement. The
      Trustee hereby accepts such assignment, and shall be entitled to exercise all
      the rights of the Depositor under the Mortgage Loan Sale Agreement as if, for
      such purpose, it were the Depositor. 

     

    It
      is
      agreed and understood by the Depositor and the Trustee (and the Seller has
      so
      represented and recognized in the Mortgage Loan Sale Agreement) that it is
      not
      intended that any Mortgage Loan to be included in the Trust Fund be (i) a
“High-Cost
      Home Loan” as defined in the New Jersey Home Ownership Act effective November
      27, 2003, (ii) a “High-Cost Home Loan” as defined in the New Mexico Home Loan
      Protection Act effective January 1, 2004, (iii) a “High-Cost Home Mortgage Loan”
as defined in the Massachusetts Predatory Home Loan Practices Act effective
      November 7, 2004 or (iv) a “High Cost Home Loan” as defined in the Indiana Home
      Loan Practices Act effective January 1, 2005. 

     

    The
      foregoing sale, transfer, assignment, set-over, deposit and conveyance does
      not
      and is not intended to result in the creation or assumption by the Trustee
      of
      any obligation of the Depositor, the Seller or any other Person in connection
      with the Mortgage Loans or any other agreement or instrument relating thereto
      except as specifically set forth therein.

     

    (b) In
      connection with such transfer and assignment, the Depositor does hereby deliver
      to, and deposit with, or cause to be delivered to and deposited with, the
      Trustee, and/or the applicable Custodian acting on the Trustee’s behalf, the
      following documents or instruments with respect to each Mortgage Loan (each
      a
“Mortgage File”) so transferred and assigned:

     

    (i) with
      respect to each Mortgage Loan, the original Mortgage Note endorsed without
      recourse in proper form to the order of the Trustee, as shown on Exhibit B-4
      hereto, or in blank (in each case, with all necessary intervening endorsements,
      as applicable) or with respect to any lost Mortgage Note, a lost note affidavit
      stating that the original Mortgage Note was lost, misplaced or destroyed,
      together with a copy of the related Mortgage Note;

     

    (ii) if
      applicable, the original of any guarantee, security agreement or pledge
      agreement executed in connection with the Mortgage Note, assigned to the
      Trustee;

     

    (iii) with
      respect to any Mortgage Loan, the original recorded Mortgage with evidence
      of
      recording indicated thereon and the original recorded power of attorney, with
      evidence of recording thereon. If, in connection with any Mortgage Loan, the
      Depositor cannot deliver the Mortgage or power of attorney with evidence of
      recording thereon on or prior to the Closing Date because of a delay caused
      by
      the public recording office where such Mortgage has been delivered for
      recordation or because such Mortgage or power of attorney has been lost, the
      Depositor shall deliver or cause to be delivered to the Trustee (or the
      applicable Custodian), in the case of a delay due to recording, a true copy
      of
      such Mortgage or power of attorney, pending delivery of the original thereof,
      together with an Officer’s Certificate of the Depositor certifying that the copy
      of such Mortgage or power of attorney delivered to the Trustee (or the
      applicable Custodian) is a true copy and that the original of such Mortgage
      or
      power of attorney has been forwarded to the public recording office, or, in
      the
      case of a Mortgage or power of attorney that has been lost, a copy thereof
      (certified as provided for under the laws of the appropriate jurisdiction)
      and a
      written Opinion of Counsel delivered to the Trustee and the Depositor that
      an
      original recorded Mortgage or power of attorney is not required to enforce
      the
      Trustee’s interest in the Mortgage Loan;

     

    
      
        
        

      

      
        52

        
          

        

      

      
        
        

      

    

     

    (iv) the
      original of each assumption, modification or substitution agreement, if any,
      relating to the Mortgage Loans, or, as to any assumption, modification or
      substitution agreement which cannot be delivered on or prior to the Closing
      Date
      because of a delay caused by the public recording office where such assumption,
      modification or substitution agreement has been delivered for recordation,
      a
      photocopy of such assumption, modification or substitution agreement, pending
      delivery of the original thereof, together with an Officer’s Certificate of the
      Depositor certifying that the copy of such assumption, modification or
      substitution agreement delivered to the Trustee (or the related Custodian)
      is a
      true copy and that the original of such agreement has been forwarded to the
      public recording office;

     

    (v) with
      respect to each Non-MERS Mortgage Loan, an original Assignment of Mortgage,
      in
      form and substance acceptable for recording. The related Mortgage shall be
      assigned either (A) in blank, without recourse or (B) to “Citibank, N.A., as
      Trustee of the Structured Asset Securities Corporation Mortgage Pass Through
      Certificates, Series 2006-S4, without recourse”;

     

    (vi) if
      applicable, such original intervening assignments of the Mortgage, notice of
      transfer or equivalent instrument (each, an “Intervening Assignment”), as may be
      necessary to show a complete chain of assignment from the originator, or, in
      the
      case of an Intervening Assignment that has been lost, a written Opinion of
      Counsel delivered to the Trustee that such original Intervening Assignment
      is
      not required to enforce the Trustee’s interest in the Mortgage
      Loan;

     

    (vii) with
      respect to any Mortgage Loan, the original mortgagee title insurance policy
      (or,
      in lieu thereof, a commitment to issue such title insurance policy with an
      original or certified copy of such title insurance policy to follow as soon
      after the Closing Date as reasonably practicable) or attorney’s opinion of title
      and abstract of title and, if applicable, the original Primary Mortgage
      Insurance Policy or certificate;

     

    (viii) the
      original of any security agreement, chattel mortgage or equivalent instrument
      executed in connection with the Mortgage or as to any security agreement,
      chattel mortgage or their equivalent instrument that cannot be delivered on
      or
      prior to the Closing Date because of a delay caused by the public recording
      office where such document has been delivered for recordation, a photocopy
      of
      such document, pending delivery of the original thereof, together with an
      Officer’s Certificate of the Depositor certifying that the copy of such security
      agreement, chattel mortgage or their equivalent instrument delivered to the
      Trustee (or the applicable Custodian) is a true copy and that the original
      of
      such document has been forwarded to the public recording office;
      and

     

    
      
        
        

      

      
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    (ix) with
      respect to any manufactured housing contract, any related manufactured housing
      sales contract, installment loan agreement or participation
      interest.

     

    The
      parties hereto acknowledge and agree that the form of endorsement attached
      hereto as Exhibit B-4 is intended to effect the transfer to the Trustee, for
      the
      benefit of the Certificateholders, of the Mortgage Notes and the
      Mortgages.

     

    (c) (i)
       Assignments of Mortgage with respect to each Non-MERS Mortgage Loan shall
      be recorded; provided,
      however,
      that
      such Assignments need not be recorded if, on or prior to the Closing Date,
      the
      Depositor delivers, at its own expense, an Opinion of Counsel addressed to
      the
      Trustee (which must be Independent counsel) acceptable to the Trustee and the
      Rating Agencies, to the effect that recording in such states is not required
      to
      protect the Trustee’s interest in the related Non-MERS Mortgage Loans;
provided,
      further,
      that
      notwithstanding the delivery of any Opinion of Counsel, the Master Servicer
      shall cause the Servicer to submit each Assignment of Mortgage for recording
      upon the occurrence of a bankruptcy, insolvency or foreclosure relating to
      the
      Mortgagor under the related Mortgage. Subject to the preceding sentence, as
      soon
      as practicable after the Closing Date (but in no event more than three months
      thereafter except to the extent delays are caused by the applicable recording
      office), the Master Servicer, at the expense of the Depositor and with the
      cooperation of the Servicer, shall cause to be properly recorded by the Servicer
      in each public recording office where the related Mortgages are recorded each
      Assignment of Mortgage referred to in subsection (b)(v) above with respect
      to
      each Non-MERS Mortgage Loan. 

     

    (ii)
       With
      respect to each MERS Mortgage Loan, the Master Servicer shall cause the
      Servicer, at the expense of the Depositor, to take such actions as are necessary
      to cause the Trustee to be clearly identified as the owner of each such Mortgage
      Loan on the records of MERS for purposes of the system of recording transfers
      of
      beneficial ownership of mortgages maintained by MERS.

     

    (d) In
      instances where a Title Insurance Policy is required to be delivered to the
      Trustee or the applicable Custodian on behalf of the Trustee under clause
      (b)(vii) above and is not so delivered, the Depositor will provide a copy of
      such Title Insurance Policy to the Trustee, or to the applicable Custodian
      on
      behalf of the Trustee, as promptly as practicable after the execution and
      delivery hereof, but in any case within 180 days of the Closing
      Date.

     

    (e) For
      Mortgage Loans (if any) that have been prepaid in full after the Cut-off Date
      and prior to the Closing Date, the Depositor, in lieu of delivering the above
      documents, herewith delivers to the Trustee, or to the applicable Custodian
      on
      behalf of the Trustee, an Officer’s Certificate which shall include a statement
      to the effect that all amounts received in connection with such prepayment
      that
      are required to be deposited in the Collection Account pursuant to Section
      4.01
      have been so deposited. All original documents that are not delivered to the
      Trustee or the applicable Custodian on behalf of the Trustee shall be held
      by
      the Master Servicer or the Servicer in trust for the benefit of the Trustee
      and
      the Certificateholders.

     

    
      
        
        

      

      
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    (f) The
      Depositor shall have the right to receive any and all loan-level information
      regarding the characteristics and performance of the Mortgage Loans upon
      request, and to publish, disseminate or otherwise utilize such information
      in
      its discretion, subject to applicable laws and regulations.

     

    
      	 	
              Section
                2.02 

            	
              Acceptance
                of Trust Fund by Trustee: Review of Documentation for Trust
                Fund.  

            


    

     

    (a) The
      Trustee, by execution and delivery hereof, acknowledges receipt by it or by
      the
      applicable Custodian on its behalf of the Mortgage Files pertaining to the
      Mortgage Loans listed on the Mortgage Loan Schedule, subject to review thereof
      by the Trustee, or by the applicable Custodian on behalf of the Trustee, under
      this Section 2.02. The Trustee, or the applicable Custodian on behalf of the
      Trustee, will execute and deliver to the Depositor, the Master Servicer and
      the
      Trustee on the Closing Date an Initial Certification in the form annexed hereto
      as Exhibit B-1 (or in the form annexed to the applicable Custodial Agreement
      as
      Exhibit B-1, as applicable).

     

    (b) Within
      45
      days after the Closing Date, the Trustee or the applicable Custodian on behalf
      of the Trustee, will, for the benefit of Holders of the Certificates, review
      each Mortgage File to ascertain that all required documents set forth in Section
      2.01 have been received and appear on their face to contain the requisite
      signatures by or on behalf of the respective parties thereto, and shall deliver
      to the Trustee, the Depositor and the Master Servicer an Interim Certification
      in the form annexed hereto as Exhibit B-2 (or in the form annexed to the
      applicable Custodial Agreement as Exhibit B-2, as applicable) to the effect
      that, as to each Mortgage Loan listed in the Mortgage Loan Schedule (other
      than
      any Mortgage Loan prepaid in full or any Mortgage Loan specifically identified
      in such certification as not covered by such certification), (i) all of the
      applicable documents specified in Section 2.01(b) are in its possession and
      (ii)
      such documents have been reviewed by it and appear to relate to such Mortgage
      Loan. The Trustee, or the applicable Custodian on behalf of the Trustee, shall
      determine whether such documents are executed and endorsed, but shall be under
      no duty or obligation to inspect, review or examine any such documents,
      instruments, certificates or other papers to determine that the same are valid,
      binding, legally effective, properly endorsed, genuine, enforceable or
      appropriate for the represented purpose or that they have actually been recorded
      or are in recordable form or that they are other than what they purport to
      be on
      their face. Neither the Trustee nor any applicable Custodian shall have any
      responsibility for verifying the genuineness or the legal effectiveness of
      or
      authority for any signatures of or on behalf of any party or
      endorser.

     

    (c) If
      in the
      course of the review described in paragraph (b) above the Trustee or the
      applicable Custodian discovers any document or documents constituting a part
      of
      a Mortgage File that is missing, does not appear regular on its face (i.e.,
      is
      mutilated, damaged, defaced, torn or otherwise physically altered) or appears
      to
      be unrelated to the Mortgage Loans identified in the Mortgage Loan Schedule
      (each, a “Material Defect”), the Trustee, or the applicable Custodian on behalf
      of the Trustee, discovering such Material Defect shall promptly identify the
      Mortgage Loan to which such Material Defect relates in the Interim Certification
      delivered to the Trustee, the Depositor and the Master Servicer. Within 90
      days
      of its receipt of such notice, the Depositor shall be required to cure such
      Material Defect (and, in such event, the Depositor shall provide the Trustee
      with an Officer’s Certificate confirming that such cure has been effected). If
      the Depositor does not so cure such Material Defect, the Depositor shall, if
      a
      loss has been incurred with respect to such Mortgage Loan that would, if such
      Mortgage Loan were not purchased from the Trust Fund, constitute a Realized
      Loss, and such loss is attributable to the failure of the Depositor to cure
      such
      Material Defect, repurchase the related Mortgage Loan from the Trust Fund at
      the
      Purchase Price. A loss shall be deemed to be attributable to the failure of
      the
      Depositor to cure a Material Defect if, as determined by the Depositor, upon
      mutual agreement with the Trustee each acting in good faith, absent such
      Material Defect, such loss would not have been incurred. Within the two-year
      period following the Closing Date, the Depositor may, in lieu of repurchasing
      a
      Mortgage Loan pursuant to this Section 2.02, substitute for such Mortgage Loan
      a
      Qualifying Substitute Mortgage Loan subject to the provisions of Section 2.05.
      The failure of the Trustee or the applicable Custodian to give the notice
      contemplated herein within 45 days after the Closing Date shall not affect
      or
      relieve the Depositor of its obligation to repurchase any Mortgage Loan pursuant
      to this Section 2.02 or any other Section of this Agreement requiring the
      repurchase of Mortgage Loans from the Trust Fund.

     

    
      
        
        

      

      
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    (d) Within
      180 days following the Closing Date, the Trustee, or the applicable Custodian,
      shall deliver to the Trustee, the Depositor and the Master Servicer a Final
      Certification substantially in the form attached as Exhibit B-3 (or in the
      form
      annexed to the applicable Custodial Agreement as Exhibit B-3, as applicable)
      evidencing the completeness of the Mortgage Files in its possession or control,
      with any exceptions noted thereto.

     

    (e) Nothing
      in this Agreement shall be construed to constitute an assumption by the Trust
      Fund, the Trustee, any Custodian or the Certificateholders of any unsatisfied
      duty, claim or other liability on any Mortgage Loan or to any
      Mortgagor.

     

    (f) Each
      of
      the parties hereto acknowledges that the applicable Custodian shall perform
      the
      applicable review of the Mortgage Loans and respective certifications thereof
      as
      provided in this Section 2.02 and the applicable Custodial Agreement. The
      Trustee is hereby authorized and directed by the Depositor to appoint each
      such
      Custodian and to execute and deliver each of the Custodial Agreements and to
      execute and deliver Transaction Addendum SASCO 2006-S4 to the Master Consulting
      Agreement with the Credit Risk Manager.

     

    (g) Upon
      execution of this Agreement, the Depositor hereby delivers to the Trustee and
      the Trustee acknowledges a receipt of the Mortgage Loan Sale Agreement and
      the
      Servicing Agreement. The Depositor hereby directs the Trustee, solely in its
      capacity as Trustee hereunder, to execute and deliver, concurrently with the
      execution and delivery of this Agreement, the Servicing Agreement.

     

    
      	 	
              Section
                2.03 

            	
              Representations
                and Warranties of the Depositor. 

            


    

     

    The
      Depositor hereby represents and warrants to the Trustee, for the benefit of
      Certificateholders and the Master Servicer as of the Closing Date or such other
      date as is specified, that:

     

    
      
        
        

      

      
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    (i) the
      Depositor is a corporation duly organized, validly existing and in good standing
      under the laws governing its creation and existence and has full corporate
      power
      and authority to own its property, to carry on its business as presently
      conducted, to enter into and perform its obligations under this Agreement,
      and
      to create the trust pursuant hereto;

     

    (ii) the
      execution and delivery by the Depositor of this Agreement have been duly
      authorized by all necessary corporate action on the part of the Depositor;
      none
      of the execution and delivery of this Agreement, the consummation of the
      transactions herein contemplated, or compliance with the provisions hereof
      will
      conflict with or result in a breach of, or constitute a default under, any
      of
      the provisions of any law, governmental rule, regulation, judgment, decree
      or
      order binding on the Depositor or its properties or the certificate of
      incorporation or bylaws of the Depositor;

     

    (iii) the
      execution, delivery and performance by the Depositor of this Agreement and
      the
      consummation of the transactions contemplated hereby do not require the consent
      or approval of, the giving of notice to, the registration with, or the taking
      of
      any other action in respect of, any state, federal or other governmental
      authority or agency, except such as has been obtained, given, effected or taken
      prior to the date hereof;

     

    (iv) this
      Agreement has been duly executed and delivered by the Depositor and, assuming
      due authorization, execution and delivery by the Trustee, the Master Servicer
      and the Credit Risk Manager, constitutes a valid and binding obligation of
      the
      Depositor enforceable against it in accordance with its terms except as such
      enforceability may be subject to (A) applicable bankruptcy and insolvency laws
      and other similar laws affecting the enforcement of the rights of creditors
      generally and (B) general principles of equity regardless of whether such
      enforcement is considered in a proceeding in equity or at law;

     

    (v) there
      are
      no actions, suits or proceedings pending or, to the knowledge of the Depositor,
      threatened or likely to be asserted against or affecting the Depositor, before
      or by any court, administrative agency, arbitrator or governmental body (A)
      with
      respect to any of the transactions contemplated by this Agreement or (B) with
      respect to any other matter which in the judgment of the Depositor will be
      determined adversely to the Depositor and will if determined adversely to the
      Depositor materially and adversely affect it or its business, assets, operations
      or condition, financial or otherwise, or adversely affect its ability to perform
      its obligations under this Agreement; and

     

    (vi) immediately
      prior to the transfer and assignment of the Mortgage Loans to the Trustee,
      the
      Depositor was the sole owner of record and holder of each Mortgage Loan, and
      the
      Depositor had good and marketable title thereto, and had full right to transfer
      and sell each Mortgage Loan to the Trustee free and clear, subject only to
      (1)
      any senior lien mortgage on the related Mortgaged Property, (2) liens of current
      real property taxes and assessments not yet due and payable and, if the related
      Mortgaged Property is a condominium unit, any lien for common charges permitted
      by statute, (3) covenants, conditions and restrictions, rights of way, easements
      and other matters of public record as of the date of recording of such Mortgage
      acceptable to mortgage lending institutions in the area in which the related
      Mortgaged Property is located and specifically referred to in the lender’s Title
      Insurance Policy or attorney’s opinion of title and abstract of title delivered
      to the originator of such Mortgage Loan, and (4) such other matters to which
      like properties are commonly subject which do not, individually or in the
      aggregate, materially interfere with the benefits of the security intended
      to be
      provided by the Mortgage, of any encumbrance, equity, participation interest,
      lien, pledge, charge, claim or security interest, and had full right and
      authority, subject to no interest or participation of, or agreement with, any
      other party, to sell and assign each Mortgage Loan pursuant to this
      Agreement.

     

    
      
        
        

      

      
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              Section
                2.04 

            	
              Discovery
                of Breach. 

            


    

     

    It
      is
      understood and agreed that the representations,
      covenants and warranties (i) of the Depositor set forth in Section 2.03, (ii)
      of
      the Seller set forth in the Mortgage Loan Sale Agreement and assigned to the
      Depositor by the Seller under the Mortgage Loan Sale Agreement and to the
      Trustee by the Depositor hereunder and (iii) of the Servicer assigned by the
      Seller to the Depositor pursuant to the Mortgage Loan Sale Agreement and
      assigned to the Trustee by the Depositor hereunder, shall each survive delivery
      of the Mortgage Files and the Assignment of Mortgage of each Mortgage Loan
      to
      the Trustee and shall continue throughout the term of this Agreement. Upon
      discovery by any of the Depositor, the Master Servicer or the Trustee of a
      breach of any of such representations and warranties that adversely and
      materially affects the value of the related Mortgage Loan, the party discovering
      such breach shall give prompt written notice to the other parties; provided,
      to
      the extent that knowledge of such breach with respect to any Mortgage Loan
      is
      known by any officer, director, employee or agent of Aurora acting in any
      capacity other than as Master Servicer hereunder, the Master Servicer shall
      not
      be deemed to have knowledge of any such breach until an officer of the Master
      Servicer has actual knowledge thereof. Within 90 days of the discovery of a
      breach of any representation or warranty given to the Trustee by the Depositor
      or given by the Seller and assigned to the Trustee, the Depositor or the Seller,
      as applicable, shall (a) cure such breach in all material respects, (b)
      repurchase such Mortgage Loan or any property acquired in respect thereof from
      the Trustee at the Purchase Price or (c) within the two-year period following
      the Closing Date, substitute a Qualifying Substitute Mortgage Loan for the
      affected Mortgage Loan.

     

    
      	 	
              Section
                2.05 

            	
              Repurchase,
                Purchase or Substitution of Mortgage
                Loans.

            


    

     

    (a) With
      respect to any Mortgage Loan repurchased by the Depositor pursuant to this
      Agreement or by the Seller pursuant to the Mortgage Loan Sale Agreement, the
      principal portion of the funds received by the Trustee in respect of such
      repurchase of a Mortgage Loan will be considered a Principal Prepayment and
      the
      Purchase Price shall be deposited in the Collection Account or a Custodial
      Account, as applicable. The Master Servicer, the Servicer, the related Custodian
      (or the Trustee in its capacity as successor master servicer, if applicable)
      shall be reimbursed from the Purchase Price for any Mortgage Loan or related
      REO
      Property for any Advances made or other amounts advanced with respect to such
      Mortgage Loan that are reimbursable to the Master Servicer or the Servicer
      under
      this Agreement or the Servicing Agreement (or to the Trustee in its capacity
      as
      successor master servicer, if applicable), together with any accrued and unpaid
      compensation due to the Master Servicer, the Servicer, the related Custodian
      or
      the Trustee hereunder or thereunder. The Trustee (i) upon receipt of the full
      amount of the Purchase Price for a Deleted Mortgage Loan, (ii) upon receipt
      of a
      written certification from the Master Servicer that it has received the full
      amount of the Purchase Price for a Deleted Mortgage Loan and has deposited
      such
      amount in the Collection Account or (iii) upon receipt of notification from
      the
      related Custodian that it had received the Mortgage File for a Qualifying
      Substitute Mortgage Loan substituted for a Deleted Mortgage Loan (and any
      applicable Substitution Amount), shall release or cause to be released and
      reassign to the Depositor or the Seller, as applicable, the related Mortgage
      File for the Deleted Mortgage Loan and shall execute and deliver such
      instruments of transfer or assignment, in each case without recourse,
      representation or warranty, as shall be necessary to vest in such party or
      its
      designee or assignee title to any Deleted Mortgage Loan released pursuant
      hereto, free and clear of all security interests, liens and other encumbrances
      created by this Agreement, which instruments shall be prepared by the Servicer
      and the Trustee shall have no further responsibility with respect to the
      Mortgage File relating to such Deleted Mortgage Loan. The Seller indemnifies
      and
      holds the Trust Fund, the Master Servicer, the Trustee and the Depositor and
      each Certificateholder harmless against any and all taxes, claims, losses,
      penalties, fines, forfeitures, reasonable legal fees and related costs,
      judgments, and any other costs, fees and expenses that the Trust Fund, the
      Trustee, the Master Servicer, the Depositor and any Certificateholder may
      sustain in connection with any actions of such Seller relating to a repurchase
      of a Mortgage Loan other than in compliance with the terms of this Section
      2.05
      and the Mortgage Loan Sale Agreement, to the extent that any such action causes
      an Adverse REMIC Event.

     

    
      
        
        

      

      
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    (b) With
      respect to each Qualifying Substitute Mortgage Loan to be delivered to the
      Trustee (or the applicable Custodian) pursuant to the terms of this Article
      II
      in exchange for a Deleted Mortgage Loan: (i) the Depositor or the Seller, as
      applicable, must deliver to the Trustee (or the applicable Custodian) the
      Mortgage File for the Qualifying Substitute Mortgage Loan containing the
      documents set forth in Section 2.01(b) along with a written certification
      certifying as to the delivery of such Mortgage File and containing granting
      language substantially comparable to that set forth in the first paragraph
      of
      Section 2.01(a); and (ii) the Depositor will be deemed to have made, with
      respect to such Qualifying Substitute Mortgage Loan, each of the representations
      and warranties made by it with respect to the related Deleted Mortgage Loan.
      As
      soon as practicable after the delivery of any Qualifying Substitute Mortgage
      Loan hereunder, the Master Servicer, at the expense of the Depositor and at
      the
      direction and with the cooperation of the Servicer, shall (i) with respect
      to a Qualifying Substitute Mortgage Loan that is a Non-MERS Mortgage Loan,
      cause
      the Assignment of Mortgage to be recorded by the Servicer if required pursuant
      to Section 2.01(c), or (ii) with respect to a Qualifying Substitute Mortgage
      Loan that is a MERS Mortgage Loan, cause to be taken such actions as are
      necessary to cause the Trustee to be clearly identified as the owner of each
      such Mortgage Loan on the records of MERS if required pursuant to Section
      2.01(c).

     

    (c) Notwithstanding
      any other provision of this Agreement, the right to substitute Mortgage Loans
      pursuant to this Article II shall be subject to the additional limitations
      that
      no substitution of a Qualifying Substitute Mortgage Loan for a Deleted Mortgage
      Loan shall be made unless the Trustee has received an Opinion of Counsel
      addressed to the Trustee (at the expense of the party seeking to make the
      substitution) that, under current law, such substitution will not cause an
      Adverse REMIC Event.

     

    
      
        
        

      

      
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              Section
                2.06 

            	
              Grant
                Clause. 

            


    

     

    (a) It
      is
      intended that the conveyance of the Depositor’s right, title and interest in and
      to property constituting the Trust Fund pursuant to this Agreement shall
      constitute, and shall be construed as, a sale of such property and not a grant
      of a security interest to secure a loan. However, if such conveyance is deemed
      to be in respect of a loan, it is intended that: (1) the rights and obligations
      of the parties shall be established pursuant to the terms of this Agreement;
      (2)
      the Depositor hereby grants to the Trustee for the benefit of the Holders of
      the
      Certificates a first priority security interest to secure repayment of an
      obligation in an amount equal to the aggregate Class Principal Amount of the
      Certificates (or the aggregate principal balance of the Lower Tier REMIC 1
      Uncertificated Regular Interests, if applicable) in all of the Depositor’s
      right, title and interest in, to and under, whether now owned or hereafter
      acquired, the Trust Fund and the Supplemental Interest Trust and all proceeds
      of
      any and all property constituting the Trust Fund and the Supplemental Interest
      Trust to secure payment of the Certificates or Lower Tier REMIC 1
      Uncertificated Regular Interests, as applicable, (such security interest being,
      to the extent of the assets that constitute the Supplemental Interest Trust,
      pari
      passu
      with the
      security interest as provided in clause (4) below); (3) this Agreement shall
      constitute a security agreement under applicable law; and (4) the Swap
      Counterparty shall be deemed, during the term of such agreement and while such
      agreement is the property of the Trustee, to have a security interest in all
      of
      the assets that constitute the Supplemental Interest Trust, but only to the
      extent of such Swap Counterparty’s right to payment under the Swap Agreement
      (such security interest being pari passu with the security interest as provided
      in clause (2) above). If such conveyance is deemed to be in respect of a loan
      and the trust created by this Agreement terminates prior to the satisfaction
      of
      the claims of any Person holding any Certificate or Lower Tier REMIC 1
      Uncertificated Regular Interests, as applicable, the security interest created
      hereby shall continue in full force and effect and the Trustee shall be deemed
      to be the collateral agent for the benefit of such Person, and all proceeds
      shall be distributed as herein provided.

     

    (b) The
      Depositor shall, to the extent consistent with this Agreement, take such
      reasonable actions as may be necessary to ensure that, if this Agreement were
      deemed to create a security interest in the Mortgage Loans and the other
      property described above, such security interest would be deemed to be a
      perfected security interest of first priority under applicable law and shall
      be
      maintained as such throughout the term of this Agreement. The Depositor shall,
      at its own expense, make all initial filings on or about the Closing Date and
      shall forward a copy of such filing or filings to the Trustee. Without limiting
      the generality of the foregoing, the Depositor shall prepare and forward for
      filing, or shall cause to be forwarded for filing, at the expense of the
      Depositor, all filings necessary to maintain the effectiveness of any original
      filings necessary under the relevant UCC to perfect the Trustee’s security
      interest in or lien on the Mortgage Loans, including without limitation (x)
      continuation statements, and (y) such other statements as may be occasioned
      by
      (1) any change of name of the Seller, the Depositor or the Trustee, (2) any
      change of location of the jurisdiction of organization of the Seller or the
      Depositor, (3) any transfer of any interest of the Seller or the Depositor
      in
      any Mortgage Loan or (4) any change under the relevant UCC or other applicable
      laws. Neither the Seller nor the Depositor shall organize under the law of
      any
      jurisdiction other than the State under which each is organized as of the
      Closing Date (whether changing its jurisdiction of organization or organizing
      under an additional jurisdiction) without giving 30 days prior written notice
      of
      such action to its immediate and intermediate transferee, including the Trustee.
      Before effecting such change, the Seller or the Depositor proposing to change
      its jurisdiction of organization shall prepare and file in the appropriate
      filing office any financing statements or other statements necessary to continue
      the perfection of the interests of its immediate and intermediate transferees,
      including the Trustee, in the Mortgage Loans. In connection with the
      transactions contemplated by this Agreement, each of the Seller and the
      Depositor authorizes its immediate or intermediate transferee to file in any
      filing office any initial financing statements, any amendments to financing
      statements, any continuation statements, or any other statements or filings
      described in this paragraph (b).

     

    
      
        
        

      

      
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    ARTICLE
      III

     

    THE
      CERTIFICATES

     

    
      	 	
              Section
                3.01 

            	
              The
                Certificates.  

            


    

     

    (a) The
      Certificates shall be issuable in registered form only and shall be securities
      governed by Article 8 of the New York Uniform Commercial Code. The Book-Entry
      Certificates will be evidenced by one or more certificates, beneficial ownership
      of which will be held in the dollar denominations in Certificate Principal
      Amount or in the Percentage Interests, specified herein. Each Class of
      Book-Entry Certificates will be issued in the minimum denominations in
      Certificate Principal Amount specified in the Preliminary Statement hereto
      and
      in integral multiples of $1 in excess thereof. The Class P and Class X
      Certificates shall each be maintained in definitive, fully registered form
      in
      the minimum denomination specified in the Preliminary Statement hereto and
      in
      integral multiples of 1% in excess thereof. Each of the Class LT-R and Class
      R
      Certificates shall be issued as a single Certificate and maintained in
      definitive, fully registered form in a minimum denomination equal to 100% of
      the
      Percentage Interest of each such Class. The Certificates may be issued in the
      form of typewritten certificates. 

     

    (b) The
      Certificates shall be executed by manual or facsimile signature on behalf of
      the
      Trustee by an authorized officer. Each Certificate shall, on original issue,
      be
      authenticated by the Trustee upon the order of the Depositor upon receipt by
      the
      Trustee (or its applicable Custodian) of the Mortgage Files described in Section
      2.01. No Certificate shall be entitled to any benefit under this Agreement,
      or
      be valid for any purpose, unless there appears on such Certificate a certificate
      of authentication substantially in the form provided for herein, executed by
      an
      authorized officer of the Trustee or the Authenticating Agent, if any, by manual
      signature, and such certification upon any Certificate shall be conclusive
      evidence, and the only evidence, that such Certificate has been duly
      authenticated and delivered hereunder. All Certificates shall be dated the
      date
      of their authentication. At any time and from time to time after the execution
      and delivery of this Agreement, the Depositor may deliver Certificates executed
      by the Depositor to the Trustee or the Authenticating Agent for authentication
      and the Trustee or the Authenticating Agent shall authenticate and deliver
      such
      Certificates as in this Agreement provided and not otherwise.

     

    (c) Any
      Class
      B Certificate offered and sold in reliance on the exemption from registration
      under Rule 144A shall be issued initially in the form of one or more permanent
      global Certificates in definitive, fully registered form without interest
      coupons with the applicable legends set forth in Exhibit A added to the forms
      of
      such Certificates (each, a “Restricted Global Security”), which shall be
      deposited on behalf of the subscribers for such Certificates represented thereby
      with the Trustee, as custodian for The Depository Trust Company (“DTC”) and
      registered in the name of a nominee of DTC, duly executed and authenticated
      by
      the Trustee as hereinafter provided. The aggregate principal amounts of the
      Restricted Global Securities may from time to time be increased or decreased
      by
      adjustments made on the records of the Trustee or DTC or its nominee, as the
      case may be, as hereinafter provided.

     

    
      
        
        

      

      
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    (d) Any
      Class
      B Certificate sold in offshore transactions in reliance on Regulation S shall
      be
      issued initially in the form of one or more permanent global Certificates in
      definitive, fully registered form without interest coupons with the applicable
      legends set forth in Exhibit A hereto added to the forms of such Certificates
      (each, a “Regulation S Global Security”), which shall be deposited on behalf of
      the subscribers for such Certificates represented thereby with the Trustee,
      as
      custodian for DTC and registered in the name of a nominee of DTC, duly executed
      and authenticated by the Trustee as hereinafter provided. The aggregate
      principal amounts of the Regulation S Global Securities may from time to time
      be
      increased or decreased by adjustments made on the records of the Trustee or
      DTC
      or its nominee, as the case may be, as hereinafter provided.

     

    (e) Any
      Class
      B Certificate sold to an “accredited investor” under Rule 501(a)(1), (2), (3) or
      (7) under the Securities Act shall be issued initially in the form of one or
      more Definitive Certificates.

     

    
      	 	
              Section
                3.02 

            	
              Registration. 

            


    

     

    The
      Trustee is hereby appointed, and hereby accepts its appointment as, Certificate
      Registrar in respect of the Certificates (and, after a Section 7.01(c) Purchase
      Event, the Lower Tier REMIC 1 Uncertificated Regular Interests) and shall
      maintain books for the registration and for the transfer of Certificates (and,
      after a Section 7.01(c) Purchase Event, the Lower Tier REMIC 1
      Uncertificated Regular Interests) (the “Certificate
      Register”). The Trustee may appoint a bank or trust company to act as
      Certificate Registrar. A registration book shall be maintained for the
      Certificates (and Lower Tier REMIC 1 Uncertificated Regular Interests, as
      the case may be) collectively. The Certificate Registrar may resign or be
      discharged or removed and a new successor may be appointed in accordance with
      the procedures and requirements set forth in Sections 6.06 and 6.07 hereof
      with
      respect to the resignation, discharge or removal of the Trustee and the
      appointment of a successor Trustee. The Certificate Registrar may appoint,
      by a
      written instrument delivered to the Holders and the Master Servicer, any bank
      or
      trust company to act as co-registrar under such conditions as the Certificate
      Registrar may prescribe; provided,
      however,
      that the
      Certificate Registrar shall not be relieved of any of its duties or
      responsibilities hereunder by reason of such appointment.

     

    Upon
      the
      occurrence of a Section 7.01(c) Purchase Event, the Master Servicer shall
      provide the Trustee with written notice of the identity of any transferee of
      the
      Master Servicer’s interest in the Lower Tier REMIC 1 Uncertificated Regular
      Interests which notice shall contain a certification that such transferee is
      a
      permitted LTURI-holder hereunder. The Lower Tier REMIC 1 Uncertificated Regular
      Interests may only be transferred in whole and not in part to no more than
      one
      LTURI-holder at a time who is either (1) an affiliate of the Master Servicer
      or
      (2) a trustee of a privately placed securitization. The Trustee and the
      Depositor shall treat the Person in whose name the Lower Tier REMIC 1
      Uncertificated Regular Interests are registered on the books of the Certificate
      Registrar as the LTURI-holder for all purposes hereunder.

     

    
      
        
        

      

      
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              Section
                3.03 

            	
              Transfer
                and Exchange of Certificates.  

            


    

     

    (a) A
      Certificate (other than a Book-Entry Certificate which shall be subject to
      Section 3.09 hereof) may be transferred by the Holder thereof only upon
      presentation and surrender of such Certificate at the office of the Certificate
      Registrar duly endorsed or accompanied by an assignment duly executed by such
      Holder or his duly authorized attorney in such form as shall be satisfactory
      to
      the Certificate Registrar. Upon the transfer of any Certificate in accordance
      with the preceding sentence, the Trustee shall execute, and the Trustee or
      any
      Authenticating Agent shall authenticate and deliver to the transferee, one
      or
      more new Certificates of the same Class and evidencing, in the aggregate, the
      same aggregate Certificate Principal Amount or Percentage Interest as the
      Certificate being transferred. No service charge shall be made to a
      Certificateholder for any registration of transfer of Certificates, but the
      Certificate Registrar may require payment of a sum sufficient to cover any
      tax
      or governmental charge that may be imposed in connection with any registration
      of transfer of Certificates.

     

    (b) A
      Certificate may be exchanged by the Holder thereof for any number of new
      Certificates of the same Class, in authorized denominations, representing in
      the
      aggregate the same Certificate Principal Amount or Percentage Interest as the
      Certificate surrendered, upon surrender of the Certificate to be exchanged
      at
      the office of the Certificate Registrar duly endorsed or accompanied by a
      written instrument of transfer duly executed by such Holder or his duly
      authorized attorney in such form as is satisfactory to the Certificate
      Registrar. Certificates delivered upon any such exchange will evidence the
      same
      obligations, and will be entitled to the same rights and privileges, as the
      Certificates surrendered. No service charge shall be made to a Certificateholder
      for any exchange of Certificates, but the Certificate Registrar may require
      payment of a sum sufficient to cover any tax or governmental charge that may
      be
      imposed in connection with any exchange of Certificates. Whenever any
      Certificates are so surrendered for exchange, the Trustee shall execute, and
      the
      Trustee or the Authenticating Agent shall authenticate, date and deliver the
      Certificates which the Certificateholder making the exchange is entitled to
      receive.

     

    (c) By
      acceptance of a Restricted Certificate or a Regulation S Global Security,
      whether upon original issuance or subsequent transfer, each Holder of such
      a
      Certificate acknowledges the restrictions on the transfer of such Certificate
      set forth thereon and agrees that it will transfer such a Certificate only
      as
      provided herein. In addition, each Holder of a Regulation S Global Security
      shall be deemed to have represented and warranted to the Trustee, the
      Certificate Registrar and any of their respective successors that: (i) such
      Person is not a U.S. person within the meaning of Regulation S and was, at
      the
      time the buy order was originated, outside the United States and (ii) such
      Person understands that such Certificates have not been registered under the
      Securities Act, and that (x) until the expiration of the 40-day distribution
      compliance period (within the meaning of Regulation S), no offer, sale, pledge
      or other transfer of such Certificates or any interest therein shall be made
      in
      the United States or to or for the account or benefit of a U.S. person (each
      as
      defined in Regulation S), (y) if in the future it decides to offer, resell,
      pledge or otherwise transfer such Certificates, such Certificates may be
      offered, resold, pledged or otherwise transferred only (A) to a person which
      the
      seller reasonably believes is a “qualified institutional buyer” (a “QIB”) as
      defined in Rule 144A, that is purchasing such Certificates for its own account
      or for the account of a qualified institutional buyer to which notice is given
      that the transfer is being made in reliance on Rule 144A or (B) in an offshore
      transaction (as defined in Regulation S) in compliance with the provisions
      of
      Regulation S, in each case in compliance with the requirements of this
      Agreement; and it will notify such transferee of the transfer restrictions
      specified in this Section.

     

    
      
        
        

      

      
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    The
      following restrictions shall apply with respect to the transfer and registration
      of transfer of a Restricted Certificate to a transferee that takes delivery
      in
      the form of a Definitive Certificate:

     

    (i) The
      Certificate Registrar shall register the transfer of a Restricted Certificate
      if
      the requested transfer is (x) to the Depositor or an affiliate (as defined
      in
      Rule 405 under the Securities Act) of the Depositor or (y) being made to a
      “qualified institutional buyer” (a “QIB”) as defined in Rule 144A by a
      transferor that has provided the Trustee with a certificate in the form of
      Exhibit F hereto; and

     

    (ii) The
      Certificate Registrar shall register the transfer of a Restricted Certificate
      if
      the requested transfer is being made to an “accredited investor” under Rule
      501(a)(1), (2), (3) or (7) under the Securities Act, or to any Person all of
      the
      equity owners in which are such accredited investors, by a transferor who
      furnishes to the Trustee a letter of the transferee substantially in the form
      of
      Exhibit G hereto.

     

    (d) (i)
      No
      transfer of an ERISA-Restricted Certificate in the form of a Definitive
      Certificate shall be made to any Person unless the Trustee has received (A)
      a
      certificate substantially in the form of Exhibit H hereto (or Exhibit D-1,
      in
      the case of a Residual Certificate) from such transferee or (B) an Opinion
      of
      Counsel, to the effect that the purchase and holding of such a Certificate
      will
      not constitute or result in prohibited transactions under Title I of ERISA
      or
      Section 4975 of the Code and will not subject the Trustee, the Master Servicer,
      the Servicer or the Depositor to any obligation in addition to those undertaken
      in the Agreement; provided,
      however,
      that
      the Trustee will not require such certificate or opinion in the event that,
      as a
      result of a change of law or otherwise, the Trustee receives an Opinion of
      Counsel to the effect that the purchase and holding of an ERISA-Restricted
      Certificate by a Plan or a Person that is purchasing or holding such a
      Certificate with the assets of a Plan will not constitute or result in a
      prohibited transaction under Title I of ERISA or Section 4975 of the Code.
      Each
      Transferee of an ERISA-Restricted Certificate that is a Book-Entry Certificate
      shall be deemed to have made the representations set forth in Exhibit H. The
      preparation and delivery of the certificate and opinions referred to above
      shall
      not be an expense of the Trust Fund, the Trustee, the Master Servicer, the
      Servicer or the Depositor.

     

    Notwithstanding
      the foregoing, no opinion or certificate shall be required for the initial
      issuance of the ERISA-Restricted Certificates. The Trustee shall have no
      obligation to monitor transfers of Book-Entry Certificates that are
      ERISA-Restricted Certificates and shall have no liability for transfers of
      such
      Certificates in violation of the transfer restrictions. The Trustee shall be
      under no liability to any Person for any registration of transfer of any
      ERISA-Restricted Certificate that is in fact not permitted by this Section
      3.03(d) or for making any payments due on such Certificate to the Holder thereof
      or taking any other action with respect to such Holder under the provisions
      of
      this Agreement so long as the transfer was registered by the Trustee in
      accordance with the foregoing requirements. The Trustee shall be entitled,
      but
      not obligated, to recover from any Holder of any ERISA-Restricted Certificate
      that was in fact a Plan or a Person acting on behalf of any such Plan any
      payments made on such ERISA-Restricted Certificate at and after either such
      time. Any such payments so recovered by the Trustee shall be paid and delivered
      by the Trustee to the last preceding Holder of such Certificate that is not
      such
      a Plan or Person acting on behalf of a Plan.

     

    
      
        
        

      

      
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    (ii) No
      transfer of an ERISA-Restricted Swap Certificate prior to the termination of
      the
      Swap Agreement shall be made unless the Trustee shall have received a
      representation letter from the transferee of such Certificate, substantially
      in
      the form set forth in Exhibit H, to the effect that either (i) such transferee
      is neither a Plan nor a Person acting on behalf of any such Plan or using the
      assets of any such Plan to effect such transfer or (ii) the acquisition and
      holding of the ERISA-Restricted Swap Certificate are eligible for exemptive
      relief under Prohibited Transaction Class Exemption (“PTCE”)
      84-14, PTCE 90-1, PTCE 91-38, PTCE 95-60 or PTCE 96-23. Notwithstanding anything
      else to the contrary herein, any purported transfer of an ERISA-Restricted
      Swap
      Certificate prior to the termination of the Swap Agreement to or on behalf
      of a
      Plan without the delivery to the Trustee of a representation letter as described
      above shall be void and of no effect. If the ERISA-Restricted Swap Certificate
      is a Book-Entry Certificate, prior to the termination of the Swap Agreement,
      the
      transferee will be deemed to have made a representation as provided in clause
      (i) or (ii) of this paragraph, as applicable.

     

    If
      any
      ERISA-Restricted Swap Certificate, or any interest therein, is acquired or
      held
      in violation of the provisions of the preceding paragraph, the next preceding
      permitted beneficial owner will be treated as the beneficial owner of that
      Certificate, retroactive to the date of transfer to the purported beneficial
      owner. Any purported beneficial owner whose acquisition or holding of an
      ERISA-Restricted Swap Certificate, or interest therein, was effected in
      violation of the provisions of the preceding paragraph shall indemnify to the
      extent permitted by law and hold harmless the Depositor, the Trustee and the
      Master Servicer from and against any and all liabilities, claims, costs or
      expenses incurred by such parties as a result of such acquisition or
      holding.

     

    To
      the
      extent permitted under applicable law (including, but not limited to, ERISA),
      the Trustee shall be under no liability to any Person for any registration
      of
      transfer of any ERISA-Restricted Swap Certificate that is in fact not permitted
      by this Section 3.03(d)(ii) or for making any payments due on such Certificate
      to the Holder thereof or taking any other action with respect to such Holder
      under the provisions of this Agreement so long as the transfer was registered
      by
      the Trustee in accordance with the foregoing requirements.

     

    (e) As
      a
      condition of the registration of transfer or exchange of any Certificate, the
      Certificate Registrar may require the certified taxpayer identification number
      of the owner of the Certificate and the payment of a sum sufficient to cover
      any
      tax or other governmental charge imposed in connection therewith; provided,
      however,
      that
      the Certificate Registrar shall have no obligation to require such payment
      or to
      determine whether or not any such tax or charge may be applicable. No service
      charge shall be made to the Certificateholder for any registration, transfer
      or
      exchange of a Certificate.

     

    Notwithstanding
      anything to the contrary contained herein, no Residual Certificate may be owned,
      pledged or transferred, directly or indirectly, by or to (i) a Disqualified
      Organization or (ii) an individual, corporation or partnership or other person
      unless such person is (A) not a Non-U.S. Person or (B) is a Non-U.S. Person
      that
      holds a Residual Certificate in connection with the conduct of a trade or
      business within the United States and has furnished the transferor and the
      Trustee with an effective Internal Revenue Service W-8ECI or successor form
      at
      the time and in the manner required by the Code (any such person who is not
      covered by clause (A) or (B) above is referred to herein as a “Non-permitted
      Foreign Holder”).

     

    
      
        
        

      

      
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    Prior
      to
      and as a condition of the registration of any transfer, sale or other
      disposition of a Residual Certificate, the proposed transferee shall deliver
      to
      the Trustee an affidavit in substantially the form attached hereto as Exhibit
      D-1 representing and warranting, among other things, that such transferee is
      not
      a Disqualified Organization, an agent or nominee acting on behalf of a
      Disqualified Organization or a Non-Permitted Foreign Holder (any such
      transferee, a “Permitted Transferee”), and the proposed transferor shall deliver
      to the Trustee an affidavit in substantially the form attached hereto as Exhibit
      D-2. In addition, the Trustee may (but shall have no obligation to) require,
      prior to and as a condition of any such transfer, the delivery by the proposed
      transferee of an Opinion of Counsel, addressed to the Depositor, the Master
      Servicer and the Trustee satisfactory in form and substance to the Depositor,
      that such proposed transferee or, if the proposed transferee is an agent or
      nominee, the proposed beneficial owner, is not a Disqualified Organization,
      agent or nominee thereof, or a Non-Permitted Foreign Holder. Notwithstanding
      the
      registration in the Certificate Register of any transfer, sale, or other
      disposition of a Residual Certificate to a Disqualified Organization, an agent
      or nominee thereof, or Non-Permitted Foreign Holder, such registration shall
      be
      deemed to be of no legal force or effect whatsoever and such Disqualified
      Organization, agent or nominee thereof, or Non-Permitted Foreign Holder shall
      not be deemed to be a Certificateholder for any purpose hereunder, including,
      but not limited to, the receipt of distributions on such Residual Certificate.
      The Trustee shall not be under any liability to any person for any registration
      or transfer of a Residual Certificate to a Disqualified Organization, agent
      or
      nominee thereof or Non-permitted Foreign Holder or for the maturity of any
      payments due on such Residual Certificate to the Holder thereof or for taking
      any other action with respect to such Holder under the provisions of the
      Agreement, so long as the transfer was effected in accordance with this Section
      3.03(e), unless a Responsible Officer of the Trustee shall have actual knowledge
      at the time of such transfer or the time of such payment or other action that
      the transferee is a Disqualified Organization, or an agent or nominee thereof,
      or Non-permitted Foreign Holder. The Trustee shall be entitled, but not
      obligated, to recover from any Holder of a Residual Certificate that was a
      Disqualified Organization, agent or nominee thereof, or Non-permitted Foreign
      Holder at the time it became a Holder or any subsequent time it became a
      Disqualified Organization, agent or nominee thereof, or Non-permitted Foreign
      Holder, all payments made on such Residual Certificate at and after either
      such
      times (and all costs and expenses, including but not limited to attorneys’ fees,
      incurred in connection therewith). Any payment (not including any such costs
      and
      expenses) so recovered by the Trustee shall be paid and delivered to the last
      preceding Holder of such Residual Certificate.

     

    If
      any
      purported transferee shall become a registered Holder of a Residual Certificate
      in violation of the provisions of this Section 3.03(e), then upon receipt of
      written notice to the Trustee that the registration of transfer of such Residual
      Certificate was not in fact permitted by this Section 3.03(e), the last
      preceding Permitted Transferee shall be restored to all rights as Holder thereof
      retroactive to the date of such registration of transfer of such Residual
      Certificate. The Trustee shall be under no liability to any Person for any
      registration of transfer of a Residual Certificate that is in fact not permitted
      by this Section 3.03(e), for making any payment due on such Certificate to
      the
      registered Holder thereof or for taking any other action with respect to such
      Holder under the provisions of this Agreement so long as the transfer was
      registered upon receipt of the affidavit described in the preceding paragraph
      of
      this Section 3.03(e).

     

    
      
        
        

      

      
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    (f) Each
      Holder or Certificate Owner of a Restricted Certificate, ERISA-Restricted
      Certificate or Residual Certificate, or an interest therein, by such Holder’s or
      Owner’s acceptance thereof, shall be deemed for all purposes to have consented
      to the provisions of this section.

     

    (g) Notwithstanding
      any provision to the contrary herein, so long as a Global Security representing
      any Class B Certificate remains outstanding and is held by or on behalf of
      DTC,
      transfers of a Global Security representing any such Certificates, in whole
      or
      in part, shall only be made in accordance with Section 3.01 and this Section
      3.03(g).

     

    (A) Subject
      to clauses (B) and (C) of this Section 3.03(g), transfers of a Global Security
      representing any Class B Certificate shall be limited to transfers of such
      Global Security, in whole or in part, to nominees of DTC or to a successor
      of
      DTC or such successor’s
      nominee.

     

    (B) Restricted
      Global Security to Regulation S Global Security. If a holder of a beneficial
      interest in a Restricted Global Security deposited with or on behalf of DTC
      wishes at any time to exchange its interest in such Restricted Global Security
      for an interest in a Regulation S Global Security, or to transfer its interest
      in such Restricted Global Security to a Person who wishes to take delivery
      thereof in the form of an interest in a Regulation S Global Security, such
      holder, provided
      such
      holder is not a U.S. person, may, subject to the rules and procedures of DTC,
      exchange or cause the exchange of such interest for an equivalent beneficial
      interest in the Regulation S Global Security. Upon receipt by the Trustee,
      as
      Certificate Registrar, of (I) instructions from DTC directing the Trustee,
      as
      Certificate Registrar, to be credited a beneficial interest in a Regulation
      S
      Global Security in an amount equal to the beneficial interest in such Restricted
      Global Security to be exchanged but not less than the minimum denomination
      applicable to such holder’s Certificates held through a Regulation S Global
      Security, (II) a written order given in accordance with DTC’s procedures
      containing information regarding the participant account of DTC and, in the
      case
      of a transfer pursuant to and in accordance with Regulation S, the Euroclear
      or
      Clearstream account to be credited with such increase and (III) a certificate
      in
      the form of Exhibit N-1 hereto given by the holder of such beneficial interest
      stating that the exchange or transfer of such interest has been made in
      compliance with the transfer restrictions applicable to the Global Securities,
      including that the holder is not a U.S. person, and pursuant to and in
      accordance with Regulation S, the Trustee, as Certificate Registrar, shall
      reduce the principal amount of the Restricted Global Security and increase
      the
      principal amount of the Regulation S Global Security by the aggregate principal
      amount of the beneficial interest in the Restricted Global Security to be
      exchanged, and shall instruct Euroclear or Clearstream, as applicable,
      concurrently with such reduction, to credit or cause to be credited to the
      account of the Person specified in such instructions a beneficial interest
      in
      the Regulation S Global Security equal to the reduction in the principal amount
      of the Restricted Global Security.

     

    
      
        
        

      

      
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    (C) Regulation
      S Global Security to Restricted Global Security. If a holder of a beneficial
      interest in a Regulation S Global Security deposited with or on behalf of DTC
      wishes at any time to transfer its interest in such Regulation S Global Security
      to a Person who wishes to take delivery thereof in the form of an interest
      in a
      Restricted Global Security, such holder may, subject to the rules and procedures
      of DTC, exchange or cause the exchange of such interest for an equivalent
      beneficial interest in a Restricted Global Security. Upon receipt by the
      Trustee, as Certificate Registrar, of (I) instructions from DTC directing the
      Trustee, as Certificate Registrar, to cause to be credited a beneficial interest
      in a Restricted Global Security in an amount equal to the beneficial interest
      in
      such Regulation S Global Security to be exchanged but not less than the minimum
      denomination applicable to such holder’s Certificates held through a Restricted
      Global Security, to be exchanged, such instructions to contain information
      regarding the participant account with DTC to be credited with such increase,
      and (II) a certificate in the form of Exhibit N-2 hereto given by the holder
      of
      such beneficial interest and stating, among other things, that the Person
      transferring such interest in such Regulation S Global Security reasonably
      believes that the Person acquiring such interest in a Restricted Global Security
      is a QIB, is obtaining such beneficial interest in a transaction meeting the
      requirements of Rule 144A and in accordance with any applicable securities laws
      of any State of the United States or any other jurisdiction, then the Trustee,
      as Certificate Registrar, will reduce the principal amount of the Regulation
      S
      Global Security and increase the principal amount of the Restricted Global
      Security by the aggregate principal amount of the beneficial interest in the
      Regulation S Global Security to be transferred and the Trustee, as Certificate
      Registrar, shall instruct DTC, concurrently with such reduction, to credit
      or
      cause to be credited to the account of the Person specified in such instructions
      a beneficial interest in the Restricted Global Security equal to the reduction
      in the principal amount of the Regulation S Global Security.

     

    (D) Other
      Exchanges. In the event that a Global Security is exchanged for Certificates
      in
      definitive registered form without interest coupons, pursuant to Section 3.09(c)
      hereof, such Certificates may be exchanged for one another only in accordance
      with such procedures as are substantially consistent with the provisions above
      (including certification requirements intended to insure that such transfers
      comply with Rule 144A, comply with Rule 501(a)(1), (2), (3) or (7) or are to
      non-U.S. persons in compliance with Regulation S under the Securities Act,
      as
      the case may be).

     

    (E) Restrictions
      on U.S. Transfers. Transfers of interests in the Regulation S Global Security
      to
      U.S. persons (as defined in Regulation S) shall be limited to transfers made
      pursuant to the provisions of Section 3.03(g)(C).

     

    
      	 	
              Section
                3.04 

            	
              Cancellation
                of Certificates. 

            


    

     

    Any
      Certificate surrendered for registration of transfer or exchange shall be
      cancelled and retained in accordance with the Trustee’s
      normal
      retention policies with respect to cancelled certificates maintained by the
      Trustee or the Certificate Registrar.

     

    
      
        
        

      

      
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              Section
                3.05 

            	
              Replacement
                of Certificates. 

            


    

     

    If
      (i)
      any Certificate is mutilated and is surrendered to the Trustee or any
      Authenticating Agent or (ii) the Trustee or any Authenticating Agent receives
      evidence to its satisfaction of the destruction, loss or theft of any
      Certificate, and there is delivered to the Trustee and the Authenticating Agent
      such security or indemnity as may be required by them to save each of them
      harmless, then, in the absence of notice to the Trustee and any Authenticating
      Agent that such destroyed, lost or stolen Certificate has been acquired by
      a
      bona fide purchaser, the Trustee shall execute and the Trustee or any
      Authenticating Agent shall authenticate and deliver, in exchange for or in
      lieu
      of any such mutilated, destroyed, lost or stolen Certificate, a new Certificate
      of like tenor and Certificate Principal Amount. Upon the issuance of any new
      Certificate under this Section 3.05, the Trustee and Authenticating Agent may
      require the payment of a sum sufficient to cover any tax or other governmental
      charge that may be imposed in relation thereto and any other expenses (including
      the fees and expenses of the Trustee or the Authenticating Agent) connected
      therewith. Any replacement Certificate issued pursuant to this Section 3.05
      shall constitute complete and indefeasible evidence of ownership in the
      applicable Trust Fund, as if originally issued, whether or not the lost, stolen
      or destroyed Certificate shall be found at any time.

     

    
      	 	
              Section
                3.06 

            	
              Persons
                Deemed Owners. 

            


    

     

    Subject
      to the provisions of Section 3.09 with respect to Book-Entry Certificates,
      the
      Depositor, the Master Servicer, the Trustee, the Certificate Registrar and
      any
      agent of any of them may treat the Person in whose name any Certificate is
      registered upon the books of the Certificate Registrar as the owner of such
      Certificate for the purpose of receiving distributions pursuant to Sections
      5.01
      and 5.02 and for all other purposes whatsoever, and none of the Depositor,
      the
      Master Servicer, the Trustee, the Certificate Registrar or any agent of any
      of
      them shall be affected by notice to the contrary.

     

    
      	 	
              Section
                3.07 

            	
              Temporary
                Certificates.  

            


    

     

    (a) Pending
      the preparation of definitive Certificates, upon the order of the Depositor,
      the
      Trustee shall execute and shall authenticate and deliver temporary Certificates
      that are printed, lithographed, typewritten, mimeographed or otherwise produced,
      in any authorized denomination, substantially of the tenor of the definitive
      Certificates in lieu of which they are issued and with such variations as the
      authorized officers executing such Certificates may determine, as evidenced
      by
      their execution of such Certificates.

     

    (b) If
      temporary Certificates are issued, the Depositor will cause definitive
      Certificates to be prepared without unreasonable delay. After the preparation
      of
      definitive Certificates, the temporary Certificates shall be exchangeable for
      definitive Certificates upon surrender of the temporary Certificates at the
      office or agency of the Trustee without charge to the Holder. Upon surrender
      for
      cancellation of any one or more temporary Certificates, the Trustee shall
      execute and authenticate and deliver in exchange therefor a like aggregate
      Certificate Principal Amount of definitive Certificates of the same Class in
      the
      authorized denominations. Until so exchanged, the temporary Certificates shall
      in all respects be entitled to the same benefits under this Agreement as
      definitive Certificates of the same Class.

     

    
      
        
        

      

      
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              Section
                3.08 

            	
              Appointment
                of Paying Agent. 

            


    

     

    (a) The
      Trustee may appoint a Paying Agent (which may be the Trustee) for the purpose
      of
      making distributions to Certificateholders hereunder. The Trustee shall cause
      such Paying Agent (if other than the Trustee) to execute and deliver to the
      Trustee an instrument in which such Paying Agent shall agree with the Trustee
      that such Paying Agent will hold all sums held by it for the payment to
      Certificateholders in an Eligible Account in trust for the benefit of the
      Certificateholders entitled thereto until such sums shall be paid to the
      Certificateholders. All funds remitted by the Trustee to any such Paying Agent
      for the purpose of making distributions shall be paid to Certificateholders
      on
      each Distribution Date and any amounts not so paid shall be returned on such
      Distribution Date to the Trustee. If the Paying Agent is not the Trustee, the
      Trustee shall cause to be remitted to the Paying Agent on or before the Business
      Day prior to each Distribution Date, by wire transfer in immediately available
      funds, the funds to be distributed on such Distribution Date. Any Paying Agent
      shall be either a bank or trust company or otherwise authorized under law to
      exercise corporate trust powers. As of the Closing Date, the Trustee shall
      be
      the Paying Agent.

     

    (b) At
      any
      time during the period that a Form 10-K is being filed with respect to the
      Trust
      Fund in accordance with the Exchange Act and the rules and regulations of the
      Commission, the Trustee shall not appoint a Paying Agent that is not the Trustee
      unless that Paying Agent first agrees in writing with the Trustee (i) to deliver
      an assessment of compliance and an accountant’s attestation in such manner and
      at such times in compliance with Section 6.01(l) and (m) of this Agreement,
      (ii)
      to comply with the provisions of Section 6.01(n), 6.01(o), 6.20(e)(i) and
      6.20(e)(iii) of this Agreement and (iii) to indemnify the Depositor and the
      Master Servicer, and their respective directors, officers, employees and agents
      and the Trust Fund and hold each of them harmless as set forth in
      6.01(p).

     

    
      	 	
              Section
                3.09 

            	
              Book-Entry
                Certificates. 

            


    

     

    (a) Each
      Class of Book-Entry Certificates, upon original issuance, shall be issued in
      the
      form of one or more typewritten Certificates representing the Book-Entry
      Certificates. The Book-Entry Certificates shall initially be registered on
      the
      Certificate Register in the name of the nominee of the Clearing Agency, and
      no
      Certificate Owner will receive a definitive certificate representing such
      Certificate Owner’s interest in the Book-Entry Certificates, except as provided
      in Section 3.09(c). Unless Definitive Certificates have been issued to
      Certificate Owners of Book-Entry Certificates pursuant to Section
      3.09(c):

     

    (i) the
      provisions of this Section 3.09 shall be in full force and effect;

     

    (ii) the
      Depositor, the Master Servicer, the Paying Agent, the Registrar and the Trustee
      may deal with the Clearing Agency for all purposes (including the making of
      distributions on the Book-Entry Certificates) as the authorized representatives
      of the Certificate Owners and the Clearing Agency shall be responsible for
      crediting the amount of such distributions to the accounts of such Persons
      entitled thereto, in accordance with the Clearing Agency’s normal
      procedures;

     

    (iii) to
      the
      extent that the provisions of this Section 3.09 conflict with any other
      provisions of this Agreement, the provisions of this Section 3.09 shall control;
      and

     

    
      
        
        

      

      
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    (iv) the
      rights of Certificate Owners shall be exercised only through the Clearing Agency
      and the Clearing Agency Participants and shall be limited to those established
      by law and agreements between such Certificate Owners and the Clearing Agency
      and/or the Clearing Agency Participants. Unless and until Definitive
      Certificates are issued pursuant to Section 3.09(c), the initial Clearing Agency
      will make book-entry transfers among the Clearing Agency Participants and
      receive and transmit distributions of principal of and interest on the
      Book-Entry Certificates to such Clearing Agency Participants.

     

    (b) Whenever
      notice or other communication to the Certificateholders is required under this
      Agreement, unless and until Definitive Certificates shall have been issued
      to
      Certificate Owners pursuant to Section 3.09(c), the Trustee shall give all
      such
      notices and communications specified herein to be given to Holders of the
      Book-Entry Certificates to the Clearing Agency.

     

    (c) If
      (i)
      (A) the Depositor advises the Trustee in writing that the Clearing Agency is
      no
      longer willing or able to discharge properly its responsibilities with respect
      to the Book-Entry Certificates, and (B) the Depositor is unable to locate a
      qualified successor or (ii) after the occurrence of an Event of Default,
      Certificate Owners representing beneficial interests aggregating not less than
      50% of the Class Principal Amount of a Class of Book-Entry Certificates
      identified as such to the Trustee by an Officer’s Certificate from the Clearing
      Agency advise the Trustee and the Clearing Agency through the Clearing Agency
      Participants in writing that the continuation of a book-entry system through
      the
      Clearing Agency is no longer in the best interests of the Certificate Owners
      of
      a Class of Book-Entry Certificates, the Trustee shall notify or cause the
      Certificate Registrar to notify the Clearing Agency to effect notification
      to
      all Certificate Owners, through the Clearing Agency, of the occurrence of any
      such event and of the availability of Definitive Certificates to Certificate
      Owners requesting the same. Upon surrender to the Trustee of the Book-Entry
      Certificates by the Clearing Agency, accompanied by registration instructions
      from the Clearing Agency for registration, the Trustee shall issue the
      Definitive Certificates. Neither the Depositor nor the Trustee shall be liable
      for any delay in delivery of such instructions and may conclusively rely on,
      and
      shall be protected in relying on, such instructions. Upon the issuance of
      Definitive Certificates all references herein to obligations imposed upon or
      to
      be performed by the Clearing Agency shall be deemed to be imposed upon and
      performed by the Trustee, to the extent applicable, with respect to such
      Definitive Certificates and the Trustee shall recognize the holders of the
      Definitive Certificates as Certificateholders hereunder. 

     

    ARTICLE
      IV

     

    ADMINISTRATION
      OF THE TRUST FUND

     

    
      	 	
              Section
                4.01 

            	
              Collection
                Account. 

            


    

     

    (a) On
      the
      Closing Date, the Master Servicer shall open and shall thereafter maintain
      a
      segregated account held in trust (the “Collection Account”), entitled
“Collection Account, Aurora Loan Services LLC, as Master Servicer, in trust
      for
      the benefit of the Holders of Structured Asset Securities Corporation Mortgage
      Pass-Through Certificates, Series 2006-S4.” The Collection Account shall relate
      solely to the Certificates and to the Lower Tier REMIC 1 Uncertificated Regular
      Interests issued by the Trust Fund hereunder, and funds in such Collection
      Account shall not be commingled with any other monies.

     

    
      
        
        

      

      
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    (b) The
      Collection Account shall be an Eligible Account. If an existing Collection
      Account ceases to be an Eligible Account, the Master Servicer shall establish
      a
      new Collection Account that is an Eligible Account within 10 days and transfer
      all funds and investment property on deposit in such existing Collection Account
      into such new Collection Account.

     

    (c) The
      Master Servicer shall give to the Trustee prior written notice of the name
      and
      address of the depository institution at which the Collection Account is
      maintained and the account number of such Collection Account. The Master
      Servicer shall take such actions as are necessary to cause the depository
      institution holding the Collection Account to hold such account in the name
      of
      the Master Servicer under this Agreement. No later than 2:00 p.m. New York
      City
      time on each Master Servicer Remittance Date, the entire amount on deposit
      in
      the Collection Account (subject to permitted withdrawals set forth in Section
      4.02), other than amounts not included in the Total Distribution Amount for
      such
      Distribution Date, shall be remitted to the Trustee for deposit into the
      Certificate Account by wire transfer in immediately available funds. The Master
      Servicer, at its option (but with prior notice to the Trustee), may choose
      to
      make daily remittances from the Collection Account to the Trustee for deposit
      into the Certificate Account.

     

    (d) The
      Master Servicer shall deposit or cause to be deposited into the Collection
      Account, no later than the second Business Day following the Closing Date,
      any
      amounts received with respect to the Mortgage Loans representing Scheduled
      Payments on the Mortgage Loans due after the Cut-off Date and unscheduled
      payments received on or after the Cut-off Date and on or before the Closing
      Date. Thereafter, the Master Servicer shall deposit or cause to be deposited
      in
      the Collection Account on the earlier of the applicable Master Servicer
      Remittance Date and two Business Days following receipt thereof, the following
      amounts received or payments made by it (other than in respect of principal
      of
      and interest on the Mortgage Loans due on or before the Cut-off
      Date):

     

    (i) all
      payments on account of principal, including Principal Prepayments, any
      Subsequent Recovery and any Scheduled Payment attributable to principal received
      after its related Due Date, on the Mortgage Loans;

     

    (ii) all
      payments on account of interest on the Mortgage Loans, including Prepayment
      Premiums, in all cases, net of the Servicing Fee with respect to each such
      Mortgage Loan, but only to the extent of the amount permitted to be withdrawn
      or
      withheld from the Collection Account in accordance with Sections 5.04 and
      9.21;

     

    (iii) any
      unscheduled payment or other recovery with respect to a Mortgage Loan not
      otherwise specified in this paragraph (d), including all Net Liquidation
      Proceeds with respect to the Mortgage Loans and REO Property, and all amounts
      received in connection with the operation of any REO Property, net of (x) any
      unpaid Servicing Fees with respect to such Mortgage Loans (but only to the
      extent of the amount permitted to be withdrawn or withheld from the Collection
      Account in accordance with Sections 5.04 and 9.21) and (y) any amounts
      reimbursable to the Servicer with respect to such Mortgage Loan under the
      Servicing Agreement and retained by the Servicer;

     

    
      
        
        

      

      
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    (iv) all
      Insurance Proceeds;

     

    (v) all
      Advances made by the Master Servicer or the Servicer pursuant to Section 5.04
      or
      the Servicing Agreement; 

     

    (vi) any
      Seller Remittance Amounts remitted by the Servicer;

     

    (vii) all
      amounts paid by the Servicer with respect to Prepayment Interest Shortfalls;
      and


     

    (viii) the
      Purchase Price of any Mortgage Loan repurchased by the Depositor, the Seller,
      the Master Servicer or any other Person and any Substitution Amount related
      to
      any Qualifying Substitute Mortgage Loan.

     

    (e) Funds
      in
      the Collection Account may be invested in Eligible Investments selected by
      and
      at the written direction of the Master Servicer, which shall mature not later
      than one Business Day prior to the Master Servicer Remittance Date (except
      that
      if such Eligible Investment is an obligation of the Trustee, then such Eligible
      Investment shall mature not later than such applicable Master Servicer
      Remittance Date) and any such Eligible Investment shall not be sold or disposed
      of prior to its maturity. All such Eligible Investments shall be made in the
      name of the Master Servicer in trust for the benefit of the Trustee and Holders
      of the Structured Asset Securities Corporation Mortgage Pass-Through
      Certificates, Series 2006-S4. All income and gain realized from any Eligible
      Investment shall be for the benefit of the Master Servicer and shall be subject
      to its withdrawal or order from time to time, subject to Section 5.05 hereof,
      and shall not be part of the Trust Fund. The amount of any losses incurred
      in
      respect of any such investments shall be deposited in such Collection Account
      by
      the Master Servicer out of its own funds, without any right of reimbursement
      therefor, immediately as realized. The foregoing requirements for deposit in
      the
      Collection Account are exclusive, it being understood and agreed that, without
      limiting the generality of the foregoing, payments of interest on funds in
      the
      Collection Account and payments in the nature of late payment charges,
      assumption fees and other incidental fees and charges relating to the Mortgage
      Loans (other than Prepayment Premiums) need not be deposited by the Master
      Servicer in the Collection Account and may be retained by the Master Servicer
      or
      the Servicer as additional servicing compensation. If the Master Servicer
      deposits in the Collection Account any amount not required to be deposited
      therein, it may at any time withdraw such amount from such Collection Account.
      

     

    
      	 	
              Section
                4.02 

            	
              Application
                of Funds in the Collection Account. 

            


    

     

    The
      Master Servicer may, from time to time, make, or cause to be made, withdrawals
      from the Collection Account for the following purposes:

     

    (i) to
      reimburse itself or the Servicer for Advances or Servicing Advances made by
      it
      or by the Servicer pursuant to Section 5.04 or the Servicing Agreement; such
      right to reimbursement pursuant to this subclause (i) is limited to amounts
      received on or in respect of a particular Mortgage Loan (including, for this
      purpose, Liquidation Proceeds and amounts representing Insurance Proceeds with
      respect to the property subject to the related Mortgage) which represent late
      recoveries (net of the Servicing Fee) of payments of principal or interest
      respecting which any such Advance was made, it being understood, in the case
      of
      any such reimbursement, that the Master Servicer’s or Servicer’s right thereto
      shall be prior to the rights of the Certificateholders;

     

    
      
        
        

      

      
        73

        
          

        

      

      
        
        

      

    

     

    (ii) to
      reimburse itself or the Servicer, following a final liquidation of a Mortgage
      Loan (except as otherwise provided in the Servicing Agreement) for any
      previously unreimbursed Advances made by it or by the Servicer (A) that it
      determines in good faith will not be recoverable from amounts representing
      late
      recoveries of payments of principal or interest respecting the particular
      Mortgage Loan as to which such Advance was made or from Liquidation Proceeds
      or
      Insurance Proceeds with respect to such Mortgage Loan and/or (B) to the extent
      that such unreimbursed Advances exceed the related Liquidation Proceeds or
      Insurance Proceeds, it being understood, in the case of each such reimbursement,
      that such Master Servicer’s or Servicer’s right thereto shall be prior to the
      rights of the Certificateholders;

     

    (iii) to
      reimburse itself or the Servicer from Liquidation Proceeds for Liquidation
      Expenses and for amounts expended by it pursuant to Section 9.22(c) or the
      Servicing Agreement in good faith in connection with the restoration of damaged
      property and, to the extent that Liquidation Proceeds after such reimbursement
      exceed the unpaid principal balance of the related Mortgage Loan, together
      with
      accrued and unpaid interest thereon at the applicable Mortgage Rate less the
      Servicing Fee Rate for such Mortgage Loan to the Due Date next succeeding the
      date of its receipt of such Liquidation Proceeds, to pay to itself out of such
      excess the amount of any unpaid assumption fees, late payment charges or other
      Mortgagor charges on the related Mortgage Loan and to retain any excess
      remaining thereafter as additional servicing compensation, it being understood,
      in the case of any such reimbursement or payment, that such Master Servicer’s or
      Servicer’s right thereto shall be prior to the rights of the
      Certificateholders;

     

    (iv) to
      reimburse itself or the Servicer for expenses incurred by and recoverable by
      or
      reimbursable to it or the Servicer pursuant to this Agreement, including,
      without limitation, Sections 9.04, 9.05(b), 9.07(a), 9.30 or 11.15;

     

    (v) to
      pay to
      the Seller any Seller Remittance Amount;

     

    (vi) to
      pay to
      the Depositor or the Seller, as applicable, with respect to each Mortgage Loan
      or REO Property acquired in respect thereof that has been purchased pursuant
      to
      this Agreement, all amounts received thereon and not distributed on the date
      on
      which the related repurchase was effected, and to pay to the applicable Person
      any Advances and Servicing Advances to the extent specified in the definition
      of
      Purchase Price;

     

    (vii) subject
      to Section 5.05, to pay to itself income earned on the investment of funds
      deposited in the Collection Account;

     

    
      
        
        

      

      
        74

        
          

        

      

      
        
        

      

    

     

    (viii) to
      make
      payments to the Trustee on each Master Servicer Remittance Date for deposit
      into
      the Certificate Account in the amount provided in Section 4.04;

     

    (ix) to
      make
      payment to itself, the Trustee and others pursuant to any other provision of
      this Agreement;

     

    (x) to
      withdraw funds deposited in error in the Collection Account;

     

    (xi) to
      clear
      and terminate the Collection Account pursuant to Section 7.02;

     

    (xii) to
      reimburse a successor Master Servicer (solely in its capacity as successor
      Master Servicer), for any fee or advance occasioned by a termination of the
      Master Servicer, and the assumption of such duties by the Trustee or a successor
      Master Servicer appointed by the Trustee pursuant to Section 6.14, in each
      case
      to the extent not reimbursed by the terminated Master Servicer, it being
      understood, in the case of any such reimbursement or payment, that the right
      of
      the Master Servicer or the Trustee thereto shall be prior to the rights of
      the
      Certificateholders; and

     

    (xiii) to
      reimburse the Servicer for such amounts as are due thereto under the Servicing
      Agreement and have not been retained by or paid to the Servicer, to the extent
      provided in the Servicing Agreement.

     

    In
      the
      event that the Master Servicer fails on any Master Servicer Remittance Date
      to
      remit to the Trustee any amounts required to be so remitted to the Trustee
      pursuant to sub-clause (viii)
      by
      such date, the Master Servicer shall pay the Trustee, for the account of the
      Trustee, interest calculated at the “prime rate” (as published in the “Money
      Rates” section of The
      Wall Street Journal)
      on such
      amounts not timely remitted for the period from and including that Master
      Servicer Remittance Date to but not including the related Distribution Date.
      The
      Master Servicer shall only be required to pay the Trustee interest for the
      actual number of days such amounts are not timely remitted (e.g.,
      one
      day’s interest, if such amounts are remitted one day after the Master Servicer
      Remittance Date).

     

    In
      connection with withdrawals made pursuant to subclauses (i), (iii), and (v)
      above, the Master Servicer’s, the Servicer’s or such other Person’s entitlement
      thereto is limited to collections or other recoveries on the related Mortgage
      Loan. The Master Servicer shall therefore keep and maintain a separate
      accounting for each Mortgage Loan it master services for the purpose of
      justifying any withdrawal made from the Collection Account it maintains pursuant
      to such subclauses (i), (iii) and (v). 

     

    
      	 	
              Section
                4.03 

            	
              Reports
                to Certificateholders. 

            


    

     

    (a) On
      each
      Distribution Date, the Trustee shall have prepared (based solely on information
      provided by the Master Servicer or the Swap Counterparty) and shall make
      available to the Swap Counterparty, the Credit Risk Manager, the Seller and
      each
      Certificateholder a report (the “Distribution Date Statement”) setting forth the
      following information (on the basis of Mortgage Loan level information obtained
      from the Master Servicer):

     

    
      
        
        

      

      
        75

        
          

        

      

      
        
        

      

    

     

    (i) the
      aggregate amount of the distribution to be made on such Distribution Date to
      the
      Holders of each Class of Certificates, to the extent applicable, allocable
      to
      principal on the Mortgage Loans, including Liquidation Proceeds and Insurance
      Proceeds, stating separately the amount attributable to scheduled principal
      payments and unscheduled payments in the nature of principal;

     

    (ii) the
      aggregate amount of the distribution to be made on such Distribution Date to
      the
      Holders of each Class of Certificates allocable to interest and the calculation
      thereof;

     

    (iii) the
      amount, if any, of any distribution to the Holders of the Class P, Class X,
      Class LT-R and Class R Certificates;

     

    (iv) (A)
      the
      aggregate amount of any Advances required to be made as of the end of the month
      immediately preceding the month in which the Distribution Date occurs by or
      on
      behalf of the Servicer (or the Master Servicer) with respect to such
      Distribution Date, (B) the aggregate amount of such Advances actually made
      and
      (C) the amount, if any, by which (A) above exceeds (B) above;

     

    (v) the
      total
      number of Mortgage Loans, the aggregate Scheduled Principal Balance of all
      the
      Mortgage Loans as of the close of business on the last day of the related
      Collection Period, after giving effect to payments allocated to principal
      reported under clause (i) above;

     

    (vi) the
      Class
      Principal Amount of each Class of Certificates, to the extent applicable, as
      of
      such Distribution Date after giving effect to payments allocated to principal
      reported under clause (i) above, separately identifying any reduction of any
      of
      the foregoing Certificate Principal Amounts due to Applied Loss Amounts;


     

    (vii) the
      amount of any Prepayment Premiums distributed to the Class P
      Certificates;

     

    (viii) the
      amount of any Realized Losses incurred with respect to the Mortgage Loans (x)
      in
      the applicable Prepayment Period and (y) in the aggregate since the Cut-off
      Date;

     

    (ix) the
      amount of the Servicing Fees and Credit Risk Manager’s Fees paid during the
      Collection Period to which such distribution relates;

     

    (x) the
      number and aggregate outstanding principal balance of Mortgage Loans, as
      reported to the Trustee by the Master Servicer, (a) remaining outstanding (b)
      Delinquent 30 to 59 days on a contractual basis, (c) Delinquent 60 to 89 days
      on
      a contractual basis, (d) Delinquent 90 or more days on a contractual basis,
      (e)
      as to which foreclosure proceedings have been commenced, each as of the close
      of
      business on the last Business Day of the calendar month immediately preceding
      the month in which such Distribution Date occurs, (f) in bankruptcy and (g)
      that
      are REO Properties, (h) that are Charged-off Loans and (i) that are Released
      Mortgage Loans;

     

    
      
        
        

      

      
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    (xi) the
      aggregate outstanding principal balance of any Mortgage Loans with respect
      to
      which the related Mortgaged Property became a REO Property, each as of the
      close
      of business on the last Business Day of the calendar month immediately preceding
      the month in which such Distribution Date occurs;

     

    (xii) with
      respect to substitution of Mortgage Loans in the preceding calendar month,
      the
      aggregate Scheduled Principal Balance of each Deleted Mortgage Loan, and of
      each
      Qualifying Substitute Mortgage Loan;

     

    (xiii) the
      aggregate outstanding Carryforward Interest, Net Prepayment Interest Shortfalls,
      Deferred Amounts, Basis Risk Shortfalls and Unpaid Basis Risk Shortfalls, if
      any, for each Class of Certificates, after giving effect to the distributions
      made on such Distribution Date;

     

    (xiv) the
      Certificate Interest Rate applicable to such Distribution Date with respect
      to
      each Class of Certificates (with a notation if such Certificate Interest Rate
      reflects the application of the Net Funds Cap);

     

    (xv) the
      Interest Remittance Amount and the Principal Remittance Amount applicable to
      such Distribution Date;

     

    (xvi) if
      applicable, the amount of any shortfall (i.e., the difference between the
      aggregate amounts of principal and interest which Certificateholders would
      have
      received if there were sufficient available amounts in the Certificate Account
      and the amounts actually distributed);

     

    (xvii) the
      Overcollateralization Amount after giving effect to the distributions made
      on
      such Distribution Date;

     

    (xviii) the
      amount of any Overcollateralization Deficiency after giving effect to the
      distributions made on such Distribution Date;

     

    (xix) the
      level
      of LIBOR and the Interest Rate of the LIBOR Certificates for such Distribution
      Date;

     

    (xx) [reserved];

     

    (xxi) the
      amount of any Net Swap Payment to the Supplemental Interest Trust made pursuant
      to Section 5.07(d), any Net Swap Payment to the Swap Counterparty made pursuant
      to Section 5.07(d), any Swap Termination Payment to the Supplemental Interest
      Trust made pursuant to Section 5.07(d) and any Swap Termination Payment to
      the
      Swap Counterparty made pursuant to Section 5.07(d); and

     

    (xxii) whether
      a
      Trigger Event is in effect for that Distribution Date.

     

    In
      addition to the information listed above, such Distribution Date Statement
      shall
      also include such other information as is required by Item 1121 (Sec.
      229.1121) of Regulation AB, other than those data elements specified in Item
      1121(a)(11), (12) and (14).

     

    
      
        
        

      

      
        77

        
          

        

      

      
        
        

      

    

     

    In
      the
      case of information furnished pursuant to subclauses (i), (ii) and (vi) above,
      the amounts shall (except in the case of the report delivered to the holders
      of
      the Class X Certificates) be expressed as a dollar amount per $1,000 of original
      principal amount of Certificates.

     

    On
      any
      Distribution Date after the occurrence of a Section 7.01(c) Purchase Event,
      the
      information required by subclauses (i), (ii), (iii), (iv), (v), (vii), (viii),
      (ix), (x), (xi), (xii), (xv) and (xxi) shall be provided to the Swap
      Counterparty, the Credit Risk Manager, the Seller, the Holder of the Class
      LT-R
      Certificate and the LTURI-holder with regard to the Lower Tier REMIC 1
      Uncertificated Regular Interests in lieu of the Certificates.

     

    The
      Trustee shall make such report and any additional loan level information (and,
      at its option, any additional files containing the same information in an
      alternative format) provided to it by the Master Servicer available each month
      to Certificateholders, the Rating Agencies and any other parties entitled
      thereto via the Trustee’s internet website. The Trustee’s internet website shall
      initially be located at “www.sf.citidirect.com.”
      Assistance in using the website can be obtained by calling the Trustee’s
      customer service desk at (800) 422-2066. Such parties that are unable to use
      the
      website are entitled to have a paper copy mailed to them via first class mail
      by
      calling the customer service desk and indicating such or notifying the Trustee
      at the applicable Corporate Trust Office. The Trustee shall have the right
      to
      change the way such statements are distributed in order to make such
      distribution more convenient and/or more accessible to the above parties and
      the
      Trustee shall provide timely and adequate notification to all above parties
      regarding any such changes.

     

    The
      foregoing information and reports shall be prepared and determined by the
      Trustee based solely on Mortgage Loan data provided to the Trustee by the Master
      Servicer (in a format agreed to by the Trustee and the Master Servicer) no
      later
      than 2:00 p.m. New York Time four Business Days prior to the Distribution Date
      and on the information provided to the Trustee by the Swap Counterparty. In
      preparing or furnishing the foregoing information to the Certificateholders,
      the
      Trustee shall be entitled to rely conclusively on the accuracy of the
      information or data (i) regarding the Mortgage Loans (including any First
      Payment Default Mortgage Loan) and the related REO Property, that has been
      provided to the Trustee by the Master Servicer based on information received
      by
      the Master Servicer from the Servicer and (ii) regarding the Swap Agreement,
      that has been provided by the Swap Counterparty, and the Trustee shall not
      be
      obligated to verify, recompute, reconcile or recalculate any such information
      or
      data. The Trustee shall be entitled to conclusively rely on the Mortgage Loan
      data provided by the Master Servicer and shall have no liability for any errors
      in such Mortgage Loan data. The Master Servicer shall be entitled to
      conclusively rely on the Mortgage Loan data provided by the Servicer and shall
      have no liability for any errors in such Mortgage Loan data. 

     

    (b) Upon
      the
      reasonable advance written request of any Certificateholder that is a savings
      and loan, bank or insurance company, which request, if received by the Trustee,
      shall be promptly forwarded to the Master Servicer, the Master Servicer shall
      provide, or cause to be provided, (or, to the extent that such information
      or
      documentation is not required to be provided by the Servicer under the Servicing
      Agreement, shall use reasonable efforts to obtain such information and
      documentation from the Servicer, and provide) to such Certificateholder such
      reports and access to information and documentation regarding the Mortgage
      Loans
      as such Certificateholder may reasonably deem necessary to comply with
      applicable regulations of the Office of Thrift Supervision or its successor
      or
      other regulatory authorities with respect to an investment in the Certificates;
      provided,
      however,
      that
      the Master Servicer shall be entitled to be reimbursed by such Certificateholder
      for the actual expenses incurred in providing such reports and
      access.

     

    
      
        
        

      

      
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    (c) Within
      90
      days, or such shorter period as may be required by statute or regulation, after
      the end of each calendar year, the Trustee shall, upon written request, prepare
      and make available to each Person who at any time during the calendar year
      was a
      Certificateholder of record, and to Certificate Owners (identified as such
      by
      the Clearing Agency) in accordance with applicable regulations, a report
      summarizing the items provided to the Certificateholders pursuant to Sections
      4.03(a)(i) and 4.03(a)(ii) on an annual basis as may be required to enable
      such
      Holders to prepare their federal income tax returns; provided,
      however,
      that
      this Section 4.03(c) shall not be applicable where relevant reports or summaries
      are required elsewhere in this Agreement. Such information shall also include
      the amount of original issue discount accrued on each Class of Certificates
      and
      information regarding the expenses of the Trust Fund. The Trustee shall be
      deemed to have satisfied this requirement if it forwards such information in
      any
      other format permitted by the Code. The Master Servicer shall provide the
      Trustee with such information as is necessary for the Trustee to prepare such
      reports (and the Trustee may rely solely upon such information).

     

    (d) The
      Trustee shall furnish any other information that is required by the Code and
      regulations thereunder to be made available to Certificateholders. The Master
      Servicer shall provide the Trustee with such information as is necessary for
      the
      Trustee to prepare such reports (and the Trustee may rely solely upon such
      information) to the extent such information is readily available to the Master
      Servicer.

     

    (e) So
      long
      as not prohibited by applicable law, the Master Servicer shall provide to the
      Depositor or to any party designated by the Depositor, as promptly as
      practicable upon the Depositor’s request, any and all loan-level information
      that the Depositor may request in any format reasonably requested by the
      Depositor.

     

    
      	 	
              Section
                4.04 

            	
              Certificate
                Account. 

            


    

     

    (a) The
      Trustee shall establish and maintain in its name, as trustee, a trust account
      (the “Certificate Account”) entitled “Certificate Account, Citibank, N.A., as
      Trustee, in trust for the benefit of the Holders of Structured Asset Securities
      Corporation Mortgage Pass-Through Certificates, Series 2006-S4” until disbursed
      pursuant to the terms of this Agreement. The Certificate Account shall be an
      Eligible Account and shall be for the benefit of the Certificateholders, subject
      to the rights of the Trustee set forth herein. If the existing Certificate
      Account ceases to be an Eligible Account, the Trustee shall establish a new
      Certificate Account that is an Eligible Account within 10 Business Days and
      transfer all funds and investment property on deposit in such existing
      Certificate Account into such new Certificate Account. The Certificate Account
      shall relate solely to the Certificates and the Lower Tier REMIC 1
      Uncertificated Regular Interests issued hereunder and funds in the Certificate
      Account shall be held separate and apart from and shall not be commingled with
      any other monies including, without limitation, other monies of the Trustee
      held
      under this Agreement.

     

    
      
        
        

      

      
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    (b) The
      Trustee shall deposit or cause to be deposited into the Certificate Account,
      on
      the day on which, or, if such day is not a Business Day, the Business Day
      immediately following the day on which, any monies are remitted by the Master
      Servicer to the Trustee, all such amounts. The Trustee shall make withdrawals
      from the Certificate Account only for the following purposes:

     

    (i) to
      make
      payment to itself pursuant to any provision of this Agreement or to reimburse
      itself or its agents for any amounts reimbursable to it pursuant to Sections
      6.11, 6.12 or 7.01; provided,
      however,
      that
      any amounts in excess of the annual cap described in clause (b) of the
      definition of “Interest Remittance Amount” and clause (b) of the definition of
“Principal Remittance Amount” in any Anniversary Year, other than costs and
      expenses incurred by the Trustee pursuant to Section 6.14, in connection with
      any transfer of servicing, shall not be withdrawn from the Certificate Account
      and paid to the Trustee and the Trustee’s reimbursement for such excess amounts
      shall be made pursuant to Section 5.02(b)(v) hereof;

     

    (ii) to
      withdraw amounts deposited in the Certificate Account in error;

     

    (iii) to
      pay
      itself any investment income earned with respect to funds in the Certificate
      Account invested in Eligible Investments as set forth below and to make payments
      to itself and others pursuant to any provision of this Agreement;

     

    (iv) to
      make
      distributions to Certificateholders pursuant to Article V; and

     

    (v) to
      clear
      and terminate the Certificate Account pursuant to Section 7.02.

     

    Funds
      in
      the Certificate Account may be invested by the Trustee in Eligible Investments
      (which may be obligations of the Trustee or its affiliates). If invested, all
      such investments must be payable on demand or mature no later than one Business
      Day prior to the next Distribution Date, and shall not be sold or disposed
      of
      prior to their maturity. All such Eligible Investments will be made in the
      name
      of the Trustee (in its capacity as such) or its nominee. All income and gain
      realized from any such investment for each Distribution Date shall be
      compensation to the Trustee and be subject to withdrawal by the Trustee from
      time to time. The amount of any losses incurred in respect of any such
      investments shall be paid by the Trustee for deposit in the Certificate Account
      out of its own funds, without any right of reimbursement therefor, immediately
      as realized.
      Funds
      held in the Certificate Account may also be held uninvested.

     

     

    ARTICLE
      V

     

    DISTRIBUTIONS
      TO HOLDERS OF CERTIFICATES

     

    
      	 	
              Section
                5.01 

            	
              Distributions
                Generally.  

            


    

     

    (a) Subject
      to Section 7.01 respecting the final distribution on the Certificates or Lower
      Tier REMIC 1 Uncertificated Regular Interests, on each Distribution Date the
      Trustee or the Paying Agent shall make distributions in accordance with this
      Article V. Such distributions shall be made by wire transfer if the
      Certificateholder has provided the Trustee with wire instructions or by check
      mailed to the address of such Certificateholder as it appears in the books
      of
      the Trustee if the Certificateholder has not provided the Trustee with wire
      instructions in immediately available funds to an account specified in the
      request and at the expense of such Certificateholder.

     

    
      
        
        

      

      
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    (b) The
      final
      distribution in respect of any Certificate shall be made only upon presentation
      and surrender of such Certificate at the Corporate Trust Office; provided,
      however,
      that
      the foregoing provisions shall not apply to any Class of Certificates as long
      as
      such Certificate remains a Book-Entry Certificate in which case all payments
      made shall be made through the Clearing Agency and its Clearing Agency
      Participants. Notwithstanding such final payment of principal of any of the
      Certificates, each Residual Certificate will remain outstanding until the
      termination of each REMIC and the payment in full of all other amounts due
      with
      respect to the Residual Certificates and at such time such final payment in
      retirement of any Residual Certificate will be made only upon presentation
      and
      surrender of such Certificate at the Corporate Trust Office. If any payment
      required to be made on the Certificates or Lower Tier REMIC 1 Uncertificated
      Regular Interests is to be made on a day that is not a Business Day, then such
      payment will be made on the next succeeding Business Day. 

     

    (c) All
      distributions or allocations made with respect to Certificateholders within
      each
      Class on each Distribution Date shall be allocated among the outstanding
      Certificates in such Class equally in proportion to their respective initial
      Class Principal Amounts (or Percentage Interests).

     

    
      	 	
              Section
                5.02 

            	
              Distributions
                from the Certificate Account. 

            


    

     

    (a) On
      each
      Distribution Date on or prior to a Section 7.01(c) Purchase Event or a
      Trust Fund Termination Event the Trustee (or the Paying Agent on behalf of
      the
      Trustee) shall withdraw from the Certificate Account the Total Distribution
      Amount (to the extent such amount is on deposit in the Certificate Account),
      and
      amounts that are available for payment to the Swap Counterparty, and shall
      allocate such amount to the interests issued in respect of each REMIC created
      pursuant to this Agreement and shall distribute such amount as specified in
      subparagraphs (b) through (g) of this Section; provided
      that
      amounts that are available for payment to the Swap Counterparty shall be paid
      on
      the related Swap Payment Date. On each Distribution Date after a Section 7.01(c)
      Purchase Event but on or prior to a Trust Fund Termination Event, the Trustee
      (or the Paying Agent on behalf of the Trustee) shall withdraw from the
      Certificate Account the Total Distribution Amount (to the extent such amount
      is
      on deposit in the Certificate Account), and amounts that are available for
      payment to the Swap Counterparty, and shall allocate such amount to the
      interests issued in respect of REMIC 1 created pursuant to this Agreement and
      shall distribute such amount as specified in subparagraphs (h) and (i) of this
      Section; provided
      that
      amounts that are available for payment to the Swap Counterparty shall be paid
      on
      the related Swap Payment Date.

     

    (b) On
      each
      Distribution Date (or, with respect to clause (i) below, on the related Swap
      Payment Date) the Trustee shall distribute the Interest Remittance Amount in
      the
      following order of priority:

     

    (i) for
      deposit into the Swap Account, an amount equal to the lesser of (x) the amount
      of any Net Swap Payment or Swap Termination Payment (not due to a Swap
      Counterparty Trigger Event) owed to the Swap Counterparty on the related Swap
      Payment Date and (y) the Interest Remittance Amount for such Distribution
      Date;

     

    
      
        
        

      

      
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    (ii) to
      the
      Class A Certificates, Current Interest and any Carryforward Interest for such
      Class and such Distribution Date;

     

    (iii) to
      each
      Class of Subordinate Certificates, in accordance with the Subordinate Priority,
      Current Interest and any Carryforward Interest for each such Class and such
      Distribution Date; 

     

    (iv) to
      the
      Credit Risk Manager, the Credit Risk Manager’s Fee;

     

    (v) to
      the
      Trustee, any amounts reimbursable pursuant to Section 4.04(b)(i) and not
      previously reimbursed to the Trustee; and

     

    (vi) for
      application as part of Monthly Excess Cashflow for such Distribution Date,
      as
      provided in subsection (d) of this Section, any Interest Remittance Amount
      remaining after application pursuant to clauses (i) through (v)
      above.

     

    (c) On
      each
      Distribution Date or related Swap Payment Date, as applicable, the Trustee
      shall
      distribute the Principal Distribution Amount for such date as
      follows:

     

    (i) On
      each
      Distribution Date (or, with respect to clause (A) below, on the related Swap
      Payment Date) (a) prior to the Stepdown Date or (b) with respect to which a
      Trigger Event is in effect, until the aggregate Certificate Principal Amount
      of
      the LIBOR Certificates equals the Target Amount for such Distribution Date,
      the
      Trustee shall distribute the Principal Distribution Amount in the following
      order of priority:

     

    (A) for
      deposit into the Swap Account, an amount equal to the lesser of (x) the amount
      of any Net Swap Payment or Swap Termination Payment (not due to a Swap
      Counterparty Trigger Event) owed to the Swap Counterparty on the related Swap
      Payment Date, to the extent not paid pursuant to Section 5.02(b)(i) and (y)
      the
      Principal Remittance Amount for such Distribution Date;

     

    (B) to
      the
      Class
      A Certificates, until the Class Principal Amount of such Class has been reduced
      to zero;

     

    (C) to
      each
      Class of Subordinate Certificates, in accordance with the Subordinate Priority,
      until the Class Principal Amount of each such Class has been reduced to zero;
      and

     

    (D) for
      application as part of Monthly Excess Cashflow for such Distribution Date,
      as
      provided in subsection (d) of
      this
      Section, any Principal Distribution Amount remaining after application pursuant
      to clauses (A) through (C) of this Section 5.02(c)(i).

     

    Any
      Principal Distribution Amount remaining on any Distribution Date after the
      Target Amount is achieved will be applied as part of Monthly Excess Cashflow
      for
      such Distribution Date as provided in subsection (d) of this
      Section.

     

    
      
        
        

      

      
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    (ii) On
      each
      Distribution Date (or, with respect to clause (A) below, on the related Swap
      Payment Date) (a) on or after the Stepdown Date and (b) with respect to which
      a
      Trigger Event is not in effect, until the aggregate Certificate Principal Amount
      of the LIBOR Certificates equals the Target Amount for such Distribution Date,
      the Principal Distribution Amount for such date will be distributed in the
      following order of priority:

     

    (A) for
      deposit into the Swap Account, an amount equal to the lesser of (x) the amount
      of any Net Swap Payment or Swap Termination Payment (not due to a Swap
      Counterparty Trigger Event)owed to the Swap Counterparty on the related Swap
      Payment Date, to the extent not paid pursuant to Section 5.02(b)(i) and (y)
      the
      Principal Remittance Amount for such Distribution Date;

     

    (B) (1)
      so
      long as any of the Subordinate Certificates are outstanding, to the Class A
      Certificates, an amount equal to the lesser of (x) the excess of (a) the
      Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account
      pursuant to clause (A) above and (y) the Senior Principal Distribution Amount
      for such Distribution Date, until the Class Principal Amount of such Class
      has
      been reduced to zero; or (2) if none of the Subordinate Certificates are
      outstanding, to the Class A Certificates, the excess of (A) the Principal
      Distribution Amount for such Distribution Date over (B) the amount paid to
      the
      Supplemental Interest Trust for deposit into the Swap Account pursuant to clause
      (A) above, until the Class Principal Amount of such Class has been reduced
      to
      zero;

     

    (C) to
      the
      Class M1 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates pursuant to clauses (A) and (B) above
      and
      (y) the M1 Principal Distribution Amount for such date, until the Class
      Principal Amount of such Class has been reduced to zero;

     

    (D) to
      the
      Class M2 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates and the Class M1 Certificates on such
      date pursuant to clauses (A) through (C) above, and (y) the M2 Principal
      Distribution Amount for such date, until the Class Principal Amount of such
      Class has been reduced to zero;

     

    (E) to
      the
      Class M3 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates and the Class M1 and Class M2
      Certificates on such date pursuant to clauses (A) through (D) above, and (y)
      the
      M3 Principal Distribution Amount for such date, until the Class Principal Amount
      of such Class has been reduced to zero;

     

    
      
        
        

      

      
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    (F) to
      the
      Class M4 Certificates, an amount equal to the lesser of (x) the excess of
      (a) the Principal Distribution Amount for such Distribution Date over (b) the
      amount paid to the Supplemental Interest Trust for deposit into the Swap Account
      or distributed to the Senior Certificates and the Class M1, Class M2 and Class
      M3 Certificates on such date pursuant to clauses (A) through (E) above, and
      (y)
      the M4 Principal Distribution Amount for such date, until the Class Principal
      Amount of such Class has been reduced to zero;

     

    (G) to
      the
      Class M5 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates and the Class M1, Class M2, Class M3
      and
      Class M4 Certificates on such date pursuant to clauses (A) through (F) above,
      and (y) the M5 Principal Distribution Amount for such date, until the Class
      Principal Amount of such Class has been reduced to zero; 

     

    (H) to
      the
      Class M6 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates and the Class M1, Class M2, Class M3,
      Class M4 and Class M5 Certificates on such date pursuant to clauses (A) through
      (G) above, and (y) the M6 Principal Distribution Amount for such date, until
      the
      Class Principal Amount of such Class has been reduced to zero;

     

    (I) to
      the
      Class M7 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates and the Class M1, Class M2, Class M3,
      Class M4, Class M5 and Class M6 Certificates on such date pursuant to clauses
      (A) through (H) above, and (y) the M7 Principal Distribution Amount for such
      date, until the Class Principal Amount of such Class has been reduced to zero;
      

     

    (J) to
      the
      Class M8 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates and the Class M1, Class M2, Class M3,
      Class M4, Class M5, Class M6 and Class M7 Certificates on such date pursuant
      to
      clauses (A) through (I) above, and (y) the M8 Principal Distribution Amount
      for
      such date, until the Class Principal Amount of such Class has been reduced
      to
      zero; 

     

    (K) to
      the
      Class M9 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates and the Class M1, Class M2, Class M3,
      Class M4, Class M5, Class M6, Class M7 and Class M8 Certificates on such date
      pursuant to clauses (A) through (J) above, and (y) the M9 Principal Distribution
      Amount for such date, until the Class Principal Amount of such Class has been
      reduced to zero;

     

    
      
        
        

      

      
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    (L) to
      the
      Class B1 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates and the Class M1, Class M2, Class M3,
      Class M4, Class M5, Class M6, Class M7, Class M8 and Class M9 Certificates
      on
      such date pursuant to clauses (A) through (K) above, and (y) the B1 Principal
      Distribution Amount for such date, until the Class Principal Amount of such
      Class has been reduced to zero; 

     

    (M) to
      the
      Class B2 Certificates, an amount equal to the lesser of (x) the excess of (a)
      the Principal Distribution Amount for such Distribution Date over (b) the amount
      paid to the Supplemental Interest Trust for deposit into the Swap Account or
      distributed to the Senior Certificates and the Class M1, Class M2, Class M3,
      Class M4, Class M5, Class M6, Class M7, Class M8, Class M9 and Class B1
      Certificates on such date pursuant to clauses (A) through (L) above, and (y)
      the
      B2 Principal Distribution Amount for such date, until the Class Principal Amount
      of such Class has been reduced to zero; and

     

    (N) for
      application as part of Monthly Excess Cashflow for such Distribution Date,
      as
      provided in Section 5.02(d), any Principal Distribution Amount remaining after
      application pursuant to clauses (A) through (M) above. 

     

    (d) On
      each
      Distribution Date, the Trustee shall distribute the Monthly Excess Cashflow
      for
      such date in the following order of priority after giving effect to
      distributions made pursuant to subsection 5.02(e)(v) below: 

     

    (i) for
      each
      Distribution Date occurring (a) before the Stepdown Date or (b) on or after
      the Stepdown Date and for which a Trigger Event is in effect, then until the
      aggregate Certificate Principal Amount of the LIBOR Certificates equals the
      Target Amount for such Distribution Date, in the following order of
      priority:

     

    (A) to
      the
Class
      A
      Certificates, in reduction of their Class Principal Amount, after giving effect
      to distributions pursuant to clause (c) above on such Distribution Date, until
      the Class Principal Amount of such Class has been reduced to zero;
      and

     

    (B) to
      each
      Class of Subordinate Certificates, in accordance with the Subordinate Priority,
      in reduction of their respective Class Principal Amounts, in each case after
      giving effect to distributions pursuant to clause (c) above on such Distribution
      Date, until the Class Principal Amount of each such Class has been reduced
      to
      zero;

     

    (ii) for
      each
      Distribution Date occurring on or after the Stepdown Date and for which a
      Trigger Event is not in effect, until the aggregate Certificate Principal Amount
      of the LIBOR Certificates equals the Target Amount for such Distribution Date,
      in the following order of priority:

     

    
      
        
        

      

      
        85

        
          

        

      

      
        
        

      

    

     

    (A) to
      the
      Class A Certificates, in reduction of their Class Principal Amount, until the
      Class Principal Amount of such Class, after giving effect to distributions
      on
      such Distribution Date, equals the Senior Target Amount;

     

    (B) to
      the
      Class M1 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amount of the Senior Certificates and the Class M1 Certificates,
      after giving effect to distributions on such Distribution Date, equals the
      M1
      Target Amount;

     

    (C) to
      the
      Class M2 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1 and Class
      M2
      Certificates, after giving effect to distributions on such Distribution Date,
      equals the M2 Target Amount;

     

    (D) to
      the
      Class M3 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1, Class
      M2
      and Class M3 Certificates, after giving effect to distributions on such
      Distribution Date, equals the M3 Target Amount;

     

    (E) to
      the
      Class M4 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1, Class
      M2,
      Class M3 and Class M4 Certificates, after giving effect to distributions on
      such
      Distribution Date, equals the M4 Target Amount;

     

    (F) to
      the
      Class M5 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1, Class
      M2,
      Class M3, Class M4 and Class M5 Certificates, after giving effect to
      distributions on such Distribution Date, equals the M5 Target Amount;


     

    (G) to
      the
      Class M6 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1, Class
      M2,
      Class M3, Class M4, Class M5 and Class M6 Certificates, after giving effect
      to
      distributions on such Distribution Date, equals the M6 Target Amount;


     

    (H) to
      the
      Class M7 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1, Class
      M2,
      Class M3, Class M4, Class M5, Class M6 and Class M7 Certificates, after giving
      effect to distributions on such Distribution Date, equals the M7 Target Amount;
      

     

    (I) to
      the
      Class M8 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1, Class
      M2,
      Class M3, Class M4, Class M5, Class M6, Class M7 and Class M8 Certificates,
      after giving effect to distributions on such Distribution Date, equals the
      M8
      Target Amount; 

     

    
      
        
        

      

      
        86

        
          

        

      

      
        
        

      

    

     

    (J) to
      the
      Class M9 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1, Class
      M2,
      Class M3, Class M4, Class M5, Class M6, Class M7, Class M8 and Class M9
      Certificates, after giving effect to distributions on such Distribution Date,
      equals the M9 Target Amount; 

     

    (K) to
      the
      Class B1 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1, Class
      M2,
      Class M3, Class M4, Class M5, Class M6, Class M7, Class M8, Class M9 and Class
      B1 Certificates, after giving effect to distributions on such Distribution
      Date,
      equals the B1 Target Amount; and

     

    (L) to
      the
      Class B2 Certificates, in reduction of their Class Principal Amount, until
      the
      Class Principal Amounts of the Senior Certificates and the Class M1, Class
      M2,
      Class M3, Class M4, Class M5, Class M6, Class M7, Class M8, Class M9, Class
      B1
      and Class B2 Certificates, after giving effect to distributions on such
      Distribution Date, equals the B2 Target Amount; 

     

    (iii) to
      the
      Class B2 and Class B1 Certificates, sequentially, in that order, in reduction
      of
      their respective Class Principal Amounts, until the Class Principal Amount
      of
      each such Class has been reduced to zero;

     

    (iv) to
      each
      Class of Subordinate Certificates, in accordance with the Subordinate Priority,
      any Deferred Amount for each such Class and such Distribution Date;

     

    (v) to
      the
      Basis Risk Reserve Fund, an amount equal to the Basis Risk Payment for such
      Distribution Date, and then from the Basis Risk Reserve Fund, in the following
      order of priority:

     

    (A) to
      the
      Class A Certificates, any applicable Basis Risk Shortfall and Unpaid Basis
      Risk
      Shortfall for each such Class and such Distribution Date;

     

    (B) to
      each
      Class of Subordinate Certificates, in accordance with the Subordinate Priority,
      any applicable Basis Risk Shortfall and Unpaid Basis Risk Shortfall for each
      such Class and such Distribution Date; and

     

    (C) to
      the
      Swap Account, for application pursuant to Sections 5.02(e)(x) and 5.02(e)(xi),
      any amounts remaining in the Basis Risk Reserve Fund, after taking into account
      distributions pursuant to clauses (A) and (B) above, in excess of the
      Required Reserve Fund Deposit for such Distribution Date;

     

    (vi) on
      the
      Distribution Date occurring in January 2010 (or the next succeeding Distribution
      Date on which sufficient funds are available in the Certificate Account to
      make
      such distributions to the Class P Certificates), $100 to the Class P
      Certificates in payment of their Class P Principal Amount; 

     

    
      
        
        

      

      
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    (vii) to
      the
      Swap Account, the Class X Distributable Amount (less any Basis Risk Payment
      for
      such Distribution Date) for such Distribution Date, for application pursuant
      to
      Sections 5.02(e)(x) and 5.02(e)(xi) below; and

     

    (viii) to
      the
      Class LT-R Certificates, any amount remaining on such date after application
      pursuant to clauses (i) through (vii) above to the extent attributable to REMIC
      1, and otherwise to the Class R Certificates.

     

    (e) On
      each
      Distribution Date (or, with respect to clauses (i), (ii), (ix) and (x) below,
      on
      the related Swap Payment Date), the Trustee shall distribute the Swap Amount
      for
      such date as follows after making all distributions under Section 5.02(d) above
      (except in the case of Section 5.02(e)(v) below, where such payments will be
      applied prior to making distributions pursuant to Section 5.02(d))
      :

     

    (i) to
      the
      Swap Counterparty, any Net Swap Payment owed to the Swap Counterparty pursuant
      to the Swap Agreement for such Swap Payment Date;

     

    (ii) to
      the
      Swap Counterparty, any unpaid Swap Termination Payment not due to a Swap
      Counterparty Trigger Event owed to the Swap Counterparty pursuant to the Swap
      Agreement for such Swap Payment Date;

     

    (iii) to
      the
      Senior Certificates, Current Interest and any Carryforward Interest for such
      Class and such Distribution Date, to the extent unpaid;

     

    (iv) to
      each
      Class of Subordinate Certificates, in accordance with the Subordinate Priority,
      Current Interest and any Carryforward Interest for each such Class and such
      Distribution Date to the extent unpaid; 

     

    (v) to
      the
      LIBOR Certificates, any amount necessary to maintain the Enhancement Target
      as
      specified in Sections 5.02(d)(i) and (ii) above for such Distribution Date,
      for
      application pursuant to the priorities set forth in such Sections; provided,
      however,
      that the
      sum of all such amounts distributed pursuant to this Section 5.02(e)(v) and
      all
      amounts distributed pursuant to Section 5.02(e)(vi) shall not exceed the
      aggregate amount of cumulative Realized Losses incurred from the Cut-off Date
      through the last day of the related Collection Period less any amounts
      previously distributed pursuant to this Section 5.02(e)(v) and Section
      5.02(e)(vi);

     

    (vi) to
      each
      Class of Subordinate Certificates, in accordance with the Subordinate Priority,
      any Deferred Amount for each such Class and such Distribution Date, to the
      extent unpaid; provided,
      however,
      that the
      sum of all such amounts distributed pursuant to this Section 5.02(e)(vi) and
      all
      amounts distributed pursuant to Section 5.02(e)(v) shall not exceed the
      aggregate amount of cumulative Realized Losses incurred from the Cut-off Date
      through the last day of the related Collection Period less any amounts
      previously distributed pursuant to this Section 5.02(e)(vi) and Section
      5.02(e)(v);

     

    
      
        
        

      

      
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    (vii) to
      the
      Senior Certificates, any Basis Risk Shortfalls and Unpaid Basis Risk Shortfalls
      for such Class for such Distribution Date;

     

    (viii) to
      the
      Subordinate Certificates, any Basis Risk Shortfalls and Unpaid Basis Risk
      Shortfalls for each such Class for such Distribution Date, for application
      pursuant to the priorities set forth in Section 5.02(d)(v)(B) to the extent
      unpaid;

     

    (ix) if
      applicable, to the Swap Termination Receipts Account for application to the
      purchase of a replacement swap agreement pursuant to Section
      5.09(a);

     

    (x) to
      the
      Swap Counterparty, any unpaid Swap Termination Payment due to a Swap
      Counterparty Trigger Event owed to the Swap Counterparty pursuant to the Swap
      Agreement;

     

    (xi) to
      the
      Class X Certificates, any remaining amount deposited into the Swap Account
      pursuant to Section 5.02(d)(v)(C) or Section 5.02(d)(vii) and any remaining
      Swap
      Amount; and

     

    (xii) on
      the
      first Distribution Date on which the Class Principal Amount of each Class of
      Certificates has been reduced to zero, to the Class X Certificates, all amounts
      remaining in the Swap Account.

     

    (f) [Reserved].

     

    (g) On
      each
      Distribution Date, an amount equal to the aggregate of all Prepayment Premiums
      collected during the preceding Prepayment Period shall be distributed to the
      Class P Certificates.

     

    (h) On
      each
      Distribution Date occurring after a Section 7.01(c) Purchase Event but on or
      prior to a Trust Fund Termination Event, the Trustee (or the Paying Agent on
      behalf of the Trustee), shall withdraw from the Certificate Account the Total
      Distribution Amount (to the extent such amount is on deposit in the Certificate
      Account) and amounts that are available for payment to the Swap Counterparty, and shall allocate such amount to the interests issued in respect
      of
      the Lower Tier REMIC 1 Uncertificated Regular Interests created pursuant to
      this
      Agreement and shall distribute such amount first,
      for
      deposit into the Swap Account, an amount equal to any Net Swap Payment or Swap
      Termination Payment owed to the Swap Counterparty on the related Swap Payment
      Date, second,
      to the
      Credit Risk Manager, the Credit Risk Manager’s Fee, third,
      to the
      Trustee, any amounts reimbursable pursuant to Section 4.04(b)(i) and not
      previously reimbursed to the Trustee and fourth,
      to the
      LTURI-holder, any remaining Total Distribution Amount to the extent payable
      on
      the Lower Tier REMIC 1 Uncertificated Regular Interests as provided in the
      Preliminary Statement, and fifth,
      to the
      Class LT-R Certificates.

     

    (i) On
      each
      Swap Payment Date occurring after a Section 7.01(c) Purchase Event but on or
      prior to a Trust Fund Termination Event, the Trustee shall distribute the Swap
      Amount for such date first,
      to the
      Swap Counterparty to pay any Net Swap Payment owed to the Swap Counterparty
      pursuant to the Swap Agreement for such Swap Payment Date; second,
      to the
      Swap Counterparty, to pay any Swap Termination Payment owed to the Swap
      Counterparty pursuant to the Swap Agreement for such Swap Payment Date,
third,
      if
      applicable, to the Swap Termination Receipts Account, for application to the
      purchase of a replacement swap agreement pursuant to Section 5.09(a); and
fourth,
      any
      remaining amount of Swap Amount, to the LTURI-holder.

     

    
      
        
        

      

      
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              Section
                5.03 

            	
              Allocation
                of Losses. 

            


    

     

    (a) On
      each
      Distribution Date, the Class Principal Amounts of the Subordinate Certificates
      will be reduced by the amount of any Applied Loss Amount for such date, in
      the
      following order of priority:

     

    (i) to
      the
      Class B2 Certificates, until the Class Principal Amount thereof has been reduced
      to zero;

     

    (ii) to
      the
      Class B1 Certificates, until the Class Principal Amount thereof has been reduced
      to zero;

     

    (iii) to
      the
      Class M9 Certificates, until the Class Principal Amount thereof has been reduced
      to zero;

     

    (iv) to
      the
      Class M8 Certificates, until the Class Principal Amount thereof has been reduced
      to zero;

     

    (v) to
      the
      Class M7 Certificates, until the Class Principal Amount thereof has been reduced
      to zero;

     

    (vi) to
      the
      Class M6 Certificates, until the Class Principal Amount thereof has been reduced
      to zero;

     

    (vii) to
      the
      Class M5 Certificates, until the Class Principal Amount thereof has been reduced
      to zero;

     

    (viii) to
      the
      Class M4 Certificates, until the Class Principal Amount thereof has been reduced
      to zero;

     

    (ix) to
      the
      Class M3 Certificates, until the Class Principal Amount thereof has been reduced
      to zero; 

     

    (x) to
      the
      Class M2 Certificates, until the Class Principal Amount thereof has been reduced
      to zero; and

     

    (xi) to
      the
      Class M1 Certificates, until the Class Principal Amount thereof has been reduced
      to zero.

     

    
      	 	
              Section
                5.04 

            	
              Advances
                by Master Servicer, Servicer and Trustee. 

            


    

     

    (a) Subject
      to Section 9.07, Advances shall be made in respect of each Master Servicer
      Remittance Date as provided herein. If, on any Determination Date, the Servicer
      determines that any Scheduled Payments due during the related Collection Period
      (other than Balloon Payments) have not been received, the Servicer shall advance
      such amount to the extent provided in the Servicing Agreement. If the Servicer
      fails to remit Advances required to be made under the Servicing Agreement,
      the
      Master Servicer shall itself make, or shall cause the successor Servicer to
      make, such Advance on the Master Servicer Remittance Date immediately following
      such Determination Date. If the Master Servicer determines that an Advance
      is
      required, it shall on the Master Servicer Remittance Date immediately following
      such Determination Date either (i) remit to the Trustee from its own funds
      (or
      funds advanced by the Servicer) for deposit in the Certificate Account
      immediately available funds in an amount equal to such Advance, (ii) cause
      to be
      made an appropriate entry in the records of the Collection Account that funds
      in
      such account being held for future distribution or withdrawal have been, as
      permitted by this Section 5.04, used by the Master Servicer to make such
      Advance, and remit such immediately available funds to the Trustee for deposit
      in the Certificate Account or (iii) make Advances in the form of any combination
      of clauses (i) and (ii) aggregating the amount of such Advance. Any funds being
      held in the Collection Account for future distribution to Certificateholders
      and
      so used shall be replaced by the Master Servicer from its own funds by
      remittance to the Trustee for deposit in the Certificate Account on or before
      any future Master Servicer Remittance Date to the extent that funds in the
      Certificate Account on such Master Servicer Remittance Date shall be less than
      payments to Certificateholders required to be made on the related Distribution
      Date. The Master Servicer and the Servicer shall be entitled to be reimbursed
      from the Collection Account for all Advances made by it as provided in Section
      4.02. Notwithstanding anything to the contrary herein, in the event the Master
      Servicer determines in its reasonable judgment that an Advance is
      non-recoverable, the Master Servicer shall be under no obligation to make such
      Advance. The Trustee shall be entitled to conclusively rely upon any
      determination by the Master Servicer that an Advance, if made, would constitute
      a non-recoverable Advance.

     

    
      
        
        

      

      
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    (b) In
      the
      event that the Master Servicer or the Servicer fails for any reason to make
      an
      Advance required to be made pursuant to this Section 5.04 on or before the
      Master Servicer Remittance Date, the Trustee, solely in its capacity as
      successor Master Servicer pursuant to Section 6.14, shall, on or before the
      related Distribution Date, deposit in the Certificate Account an amount equal
      to
      the excess of (a) Advances required to be made by the Master Servicer or the
      Servicer that would have been deposited in such Certificate Account over (b)
      the
      amount of any Advance made by the Master Servicer or the Servicer with respect
      to such Distribution Date; provided,
      however,
      that
      the Trustee shall be required to make such Advance only if it is not prohibited
      by law from doing so and it has determined that such Advance would be
      recoverable from amounts to be received with respect to such Mortgage Loan,
      including late payments, Liquidation Proceeds, Insurance Proceeds, or otherwise.
      The Trustee shall be entitled to be reimbursed from the Certificate Account
      for
      Advances made by it pursuant to this Section 5.04 as if it were the Master
      Servicer.

     

    
      	 	
              Section
                5.05 

            	
              Compensating
                Interest Payments. 

            


    

     

    The
      Master Servicer shall not be responsible for making any Compensating Interest
      Payments not made by the Servicer. Any Compensating Interest Payments made
      by
      the Servicer shall be a component of the Interest Remittance
      Amount.

     

    
      
        
        

      

      
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              Section
                5.06 

            	
              Basis
                Risk Reserve Fund.

            


    

     

    (a) On
      the
      Closing Date, the Trustee shall establish and maintain in its name, in trust
      for
      the benefit of the Certificateholders, a Basis Risk Reserve Fund, into which
      Lehman Brothers Holdings Inc. (“LBH”) shall initially deposit $1,000. The Basis
      Risk Reserve Fund shall be an Eligible Account, and funds on deposit therein
      shall be held separate and apart from, and shall not be commingled with, any
      other monies, including, without limitation, other monies of the Trustee held
      pursuant to this Agreement.

     

    (b) On
      each
      Distribution Date, the Trustee shall distribute in the order of priority and
      to
      the extent specified in Section 5.02(d)(v) of this Agreement the Basis Risk
      Payment, if any, for such Distribution Date. On any Distribution Date, any
      amounts that the Trustee is not required to distribute from the Basis Risk
      Reserve Fund pursuant to Section 5.02(d)(v) shall remain on deposit in the
      Basis
      Risk Reserve Fund.

     

    (c) Funds
      in
      the Basis Risk Reserve Fund shall be invested in Eligible Investments. The
      Class
      X Certificates shall evidence ownership of the Basis Risk Reserve Fund for
      federal income tax purposes and LBH on behalf of the Holder thereof shall direct
      the Trustee, in writing, as to investment of amounts on deposit therein. LBH
      shall be liable for any losses incurred on such investments. In the absence
      of
      written instructions from LBH as to investment of funds on deposit in the Basis
      Risk Reserve Fund, such funds shall be invested in the Morgan Stanley Prime
      Liquidity Institutional Class (302) Money Market Fund. The Basis Risk Reserve
      Fund will be terminated after a Trust Fund Termination Event.

     

    
      	 	
              Section
                5.07 

            	
              Supplemental
                Interest Trust.

            


    

     

    (a) A
      separate trust is hereby established (the “Supplemental Interest Trust”), the
      corpus of which shall be held by the Trustee, in trust, for the benefit of
      the
      Certificateholders and the Swap Counterparty. The Trustee, as trustee of the
      Supplemental Interest Trust, shall establish an account (the “Swap Account”),
      into which LBH shall initially deposit $1,000. The Swap Account shall be an
      Eligible Account, and funds on deposit therein shall be held separate and apart
      from, and shall not be commingled with, any other monies, including, without
      limitation, other monies of the Trustee held pursuant to this Agreement. After
      payment in full to the Swap Counterparty of any Net Swap Payments or Swap
      Termination Payments owed to it pursuant to the Swap Agreement, any funds
      remaining in such fund upon termination of the Swap Account shall be released
      to
      Holders of the Class X Certificates pursuant to Sections 5.02(e)(xi) and
      5.02(e)(xii).

     

    (b) [Reserved].

     

    (c) In
      addition, the Trustee, on behalf of the Supplemental Interest Trust, shall
      establish an account (the “Collateral Account”). The Collateral Account shall be
      an Eligible Account, and funds on deposit therein shall be held separate and
      apart from, and shall not be commingled with, any other monies, including,
      without limitation, other monies of the Trustee held pursuant to this
      Agreement.

     

    (d) The
      Trustee shall deposit into the Swap Account any Net Swap Payment required
      pursuant to Sections 5.02(b), (c) and (h), any Swap Termination Payment required
      pursuant to Sections 5.02(b), (c) and (h), any amounts received from the Swap
      Counterparty under the Swap Agreement and any amounts distributed from the
      Basis
      Risk Reserve Fund required pursuant to Sections 5.02(d)(v)(C) and 5.02(d)(vii),
      and shall distribute from the Swap Account any Net Swap Payment required
      pursuant to Section 5.02(e)(i) or 5.02(i), as applicable, or Swap Termination
      Payment required pursuant to Section 5.02(e)(ii), Section 5.02(e)(x) or
      Section 5.02(i), as applicable.

     

    
      
        
        

      

      
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    (e) [Reserved].

     

    (f) Funds
      in
      the Swap Account shall be invested in Eligible Investments. Any earnings on
      such
      amounts shall be distributed on each Distribution Date pursuant to Section
      5.02(e) or 5.02(i), as applicable. The Class X Certificates shall evidence
      ownership of the Swap Account for federal income tax purposes and the Holder
      thereof shall direct the Trustee, in writing, as to investment of amounts on
      deposit therein. LBH shall be liable for any losses incurred on such
      investments. In the absence of written instructions from the Class X
      Certificateholders as to investment of funds on deposit in the Swap Account,
      such funds shall be invested in the Morgan Stanley Prime Liquidity Institutional
      Class (302) Money Market Fund. Any amounts on deposit in the Swap Account in
      excess of the Swap Amount on any Distribution Date shall be held for
      distribution pursuant to Section 5.02(e) or 5.02(i), as applicable, on the
      following Distribution Date.

     

    (g) [Reserved].

     

    (h) Funds
      or
      collateral required to be held pursuant to the Credit Support Annex shall be
      deposited into the Collateral Account. Funds posted by the Swap Counterparty
      (or
      its credit support provider) in the Collateral Account shall be invested in
      Eligible Investments at the direction of the Swap Counterparty, provided no
      early Termination Date has been designated under the Swap Agreement as the
      result of a Swap Counterparty Termination Event. Any interest earnings on such
      amounts shall be remitted to the Swap Counterparty pursuant to the terms of
      the
      Credit Support Annex. For federal income tax purposes, the Swap Counterparty
      shall be considered the owner of funds deposited in the Collateral Account.
      The
      Trustee shall not be liable for any losses incurred on such investments. In
      the
      absence of written instructions from the Swap Counterparty (or its credit
      support provider) as to investment of funds on deposit in the Collateral
      Account, such funds shall be invested in the Morgan Stanley Prime Liquidity
      Institutional Class (302) Money Market Fund. On the first Distribution Date
      immediately following any Swap Payment Date as to which a shortfall exists
      with
      respect to a Net Swap Payment or a Swap Termination Payment owed by the Swap
      Counterparty as a result of its failure to make payments pursuant to the Swap
      Agreement, amounts necessary to cover such shortfall shall be removed from
      the
      Collateral Account, remitted to the Swap Account and distributed as all or
      a
      portion of such Net Swap Payment or Swap Termination Payment pursuant to Section
      5.02(e) or Section 5.02(i), as applicable. The Trustee is hereby authorized
      to
      release any amounts on deposit in the Collateral Account required to be returned
      to the Swap Counterparty (or its credit support provider) as required pursuant
      to the terms of the Swap Agreement and the Credit Support Annex.

     

    (i) Upon
      termination of the Trust Fund, any amounts remaining in the Swap Account shall
      be distributed pursuant to the priorities set forth in Section 5.02(e) or
      5.02(i), as applicable.

     

    
      
        
        

      

      
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    (j) [Reserved].

     

    (k) Upon
      termination of the Trust Fund, any amounts remaining in the Collateral Account
      shall be distributed as required pursuant to the terms of the Credit Support
      Annex.

     

    (l) It
      is the
      intention of the parties hereto that, for federal and state income and state
      and
      local franchise tax purposes, the Supplemental Interest Trust be disregarded
      as
      an entity separate from the holders of the Class X Certificates unless and
      until
      the date when either (a) there is more than one Class X Certificateholder or
      (b)
      any Class of Certificates in addition to the Class X Certificates is
      recharacterized as an equity interest in the Supplemental Interest Trust for
      federal income tax purposes. The Trustee shall not be responsible for any entity
      level tax reporting for the Supplemental Interest Trust.

     

    (m) To
      the
      extent that the Supplemental Interest Trust is determined to be a separate
      legal
      entity from the Trustee, any obligation of the Trustee under the Swap Agreement
      shall be deemed to be an obligation of the Supplemental Interest
      Trust.

     

    (n) In
      the
      event that the Swap Counterparty fails to perform any of its obligations under
      the Swap Agreement (including, without limitation, its obligations to make
      any
      payment or transfer collateral), or breaches any of its representations and
      warranties under the Swap Agreement, or in the event that an Event of Default,
      Termination Event, or Additional Termination Event occurs (as such terms are
      defined in the Swap Agreement) as the result of a Swap Counterparty Termination
      Event, the Trustee, on behalf of the Supplemental Interest Trust, shall (upon
      a
      Responsible Officer of the Trustee receiving written notice or obtaining actual
      knowledge of the occurrence thereof), no later than the next Business Day
      following such failure, breach or occurrence, notify the Swap Counterparty
      and
      give any notice of such failure and make any demand for payment pursuant to
      the
      Swap Agreement. In the event that the Swap Counterparty’s obligations under the
      Swap Agreement are at any time guaranteed by a third party, then to the extent
      that the Swap Counterparty fails to make any payment or delivery required under
      terms of the Swap Agreement, the Trustee, on behalf of the Supplemental Interest
      Trust, shall (upon a Responsible Officer of the Trustee receiving written notice
      or obtaining actual knowledge of the occurrence thereof), no later than the
      next
      Business Day following such failure, demand that such guarantor make any and
      all
      payments then required to be made by the applicable guarantor.

     

    Section
      5.08  Rights
      of Swap Counterparty. 

     

    The
      Swap
      Counterparty shall be deemed a third-party beneficiary of this Agreement to
      the
      same extent as if it were a party hereto and shall have the right, upon
      designation of an “Early
      Termination Date” (as defined in the Swap Agreement), to enforce its rights
      under this Agreement, which rights include but are not limited to the obligation
      of the Trustee (A) to deposit any Net Swap Payment required pursuant to Sections
      5.02(b), (c) and (h) and any Swap Termination Payment required pursuant to
      Sections 5.02(b), (c) and (h) into the Swap Account, (B) to deposit any amounts
      from the Basis Risk Reserve Fund required pursuant to Sections 5.02(d)(v)(C)
      and
      5.02(d)(vii) into the Swap Account, (C) to pay any Net Swap Payment required
      pursuant to Sections 5.02(e)(i) and 5.02(i), as applicable, or Swap Termination
      Payment required pursuant to Section 5.02(e)(ii), 5.02(e)(x) or 5.02(i), as
      applicable, to the Swap Counterparty and (D) to establish and maintain the
      Swap
      Account and the Collateral Account, to make such deposits thereto, investments
      therein and distributions therefrom as are required pursuant to Section 5.07.
      For the protection and enforcement of the provisions of this Section the Swap
      Counterparty shall be entitled to such relief as can be given either at law
      or
      in equity.

     

    
      
        
        

      

      
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              Section
                5.09 

            	
              Termination
                Receipts. 

            


    

     

    (a) In
      the
      event of an “Early Termination Event” as defined under the Swap Agreement, (i)
      any Swap Termination Payment made by the Swap Counterparty to the Supplemental
      Interest Trust paid pursuant to Section 5.02(e)(ix), 5.02(h) or 5.02(i), as
      applicable (“Swap Termination Receipts”), shall be deposited in a segregated
      non-interest bearing account which shall be an Eligible Account established
      by
      the Trustee (the “Swap Termination Receipts Account”) and (ii) any amounts
      received from a replacement Swap Counterparty (“Swap Replacement Receipts”)
      shall be deposited in a segregated non-interest bearing account which shall
      be
      an Eligible Account established by the Trustee (the “Swap Replacement Receipts
      Account”). Solely upon written direction of the Depositor, the Trustee shall
      invest, or cause to be invested, funds held in the Swap Termination Receipts
      Account and the Swap Replacement Receipts Account in time deposits of the
      Trustee as permitted by clause (ii) of the definition of Eligible Investments
      or
      as otherwise directed in writing by a majority of the Certificateholders. All
      such investments must be payable on demand or mature on a Swap Payment Date,
      a
      Distribution Date or such other date as directed by the Certificateholders.
      If
      no such direction is given by the Depositor, such funds shall remain uninvested.
      All such Eligible Investments will be made in the name of the Trustee of the
      Supplemental Interest Trust (in its capacity as such) or its nominee. All income
      and gain realized from any such investment shall be deposited in the Swap
      Termination Receipts Account or the Swap Replacement Receipts Account, as
      applicable, and all losses, if any, shall be borne by the related account.
      

     

    Unless
      otherwise permitted by the Rating Agencies as evidenced in a written
      confirmation, the Depositor shall arrange for replacement Swap Agreement(s)
      or
      procure a replacement guarantor, if applicable, and the Trustee shall promptly,
      at the written direction of the Depositor, use amounts on deposit in the Swap
      Termination Receipts Account, if necessary, to enter into replacement Swap
      Agreement(s) or to execute any other agreements with respect to such replacement
      guarantor, if applicable, which shall be executed and delivered by the Trustee
      on behalf of the Supplemental Interest Trust upon receipt of written
      confirmation from each Rating Agency (if required pursuant to the terms of
      the
      Swap Agreement) that such replacement Swap Agreement(s) will not result in
      the
      reduction or withdrawal of the rating of any outstanding Class of Certificates
      with respect to which it is a Rating Agency. 

     

    Amounts
      on deposit in the Swap Replacement Receipts Account shall be held for the
      benefit of the related Swap Counterparty and paid to such Swap Counterparty
      if
      the Supplemental Interest Trust is required to make a payment to such Swap
      Counterparty following an event of default or termination event with respect
      to
      the Supplemental Interest Trust under the related Swap Agreement. Any amounts
      not so applied shall, following the termination or expiration of such Swap
      Agreement, be paid to the Class X Certificates.

     

    (b) [Reserved].

     

    
      
        
        

      

      
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    ARTICLE
      VI

     

    CONCERNING
      THE TRUSTEE EVENTS OF DEFAULT

     

    
      	 	
              Section
                6.01 

            	
              Duties
                of Trustee. 

            


    

     

    (a) The
      Trustee, except during the continuance of an Event of Default of which a
      Responsible Officer of the Trustee shall have actual knowledge, undertakes
      to
      perform such duties and only such duties as are specifically set forth in this
      Agreement. Any permissive right of the Trustee provided for in this Agreement
      shall not be construed as a duty of the Trustee. If an Event of Default (of
      which a Responsible Officer of the Trustee shall have actual knowledge) has
      occurred and has not otherwise been cured or waived, the Trustee shall exercise
      such of the rights and powers vested in it by this Agreement and use the same
      degree of care and skill in their exercise as a prudent Person would exercise
      or
      use under the circumstances in the conduct of such Person’s own
      affairs.

     

    (b) The
      Trustee , upon receipt of all resolutions, certificates, statements, opinions,
      reports, documents, orders or other instruments furnished to the Trustee which
      are specifically required to be furnished pursuant to any provision of this
      Agreement, shall examine them to determine whether they are on their face in
      the
      form required by this Agreement; provided,
      however,
      that
      the Trustee shall not be responsible for the accuracy or content of any such
      resolution, certificate, statement, opinion, report, document, order or other
      instrument furnished by the Master Servicer, the Servicer, the Swap Counterparty
      or the Credit Risk Manager to the Trustee pursuant to this Agreement, and shall
      not be required to recalculate or verify any numerical information furnished
      to
      the Trustee pursuant to this Agreement. Subject to the immediately preceding
      sentence, if any such resolution, certificate, statement, opinion, report,
      document, order or other instrument is found not to conform on its face to
      the
      form required by this Agreement in a material manner the Trustee shall notify
      the Person providing such resolutions, certificates, statements, opinions,
      reports or other documents of the non-conformity, and if the instrument is
      not
      corrected to the Trustee’s satisfaction, the Trustee will provide notice thereof
      to the Certificateholders and will, at the expense of the Trust Fund, which
      expense shall be reasonable given the scope and nature of the required action,
      take such further action as directed by the Certificateholders.

     

    (c) The
      Trustee shall not have any liability arising out of or in connection with this
      Agreement, except for its negligence or willful misconduct. Notwithstanding
      anything in this Agreement to the contrary, the Trustee shall not be liable
      for
      special, indirect or consequential losses or damages of any kind whatsoever
      (including, but not limited to, lost profits). No provision of this Agreement
      shall be construed to relieve the Trustee from liability for its own negligent
      action, its own negligent failure to act or its own willful misconduct;
provided,
      however,
      that:

     

    (i) The
      Trustee shall not be personally liable with respect to any action taken,
      suffered or omitted to be taken by it in good faith in accordance with the
      direction or with the consent of Holders as provided in Section 6.18
      hereof;

     

    (ii) For
      all
      purposes under this Agreement, the Trustee shall not be deemed to have notice
      of
      any (A) Event of Default (other than resulting from a failure by the Master
      Servicer to (i) remit funds (or make Advances) or (ii) furnish information
      to
      the Trustee when required to do so) or (B)(1) a breach of the Swap
      Counterparty’s representations and warranties under the Swap Agreement or (2)
      Event of Default, Termination Event or Additional Termination Event (as such
      terms are defined in the Swap Agreement) unless a Responsible Officer of the
      Trustee has actual knowledge thereof or unless written notice of any event
      which
      is in fact such a default is received by the Trustee at the applicable Corporate
      Trust Office, and such notice references the Holders of the Certificates and
      this Agreement;

     

    
      
        
        

      

      
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    (iii) No
      provision of this Agreement shall require the Trustee to expend or risk its
      own
      funds or otherwise incur any financial liability in the performance of any
      of
      its duties hereunder, or in the exercise of any of its rights or powers, if
      it
      shall have reasonable grounds for believing that repayment of such funds or
      adequate indemnity against such risk or liability is not reasonably assured
      to
      it; and none of the provisions contained in this Agreement shall in any event
      require the Trustee to perform, or be responsible for the manner of performance
      of, any of the obligations of the Depositor or the Master Servicer under this
      Agreement; and

     

    (iv) The
      Trustee shall not be responsible for any act or omission of the Master Servicer,
      the Servicer, the Credit Risk Manager, the Depositor, the Seller, the Swap
      Counterparty or any Custodian.

     

    (d) The
      Trustee shall have no duty hereunder with respect to any complaint, claim,
      demand, notice or other document it may receive or which may be alleged to
      have
      been delivered to or served upon it by the parties as a consequence of the
      assignment of any Mortgage Loan hereunder; provided,
      however,
      that
      the Trustee shall promptly remit to the Master Servicer upon receipt any such
      complaint, claim, demand, notice or other document (i) which is delivered to
      the
      applicable Corporate Trust Office of the Trustee and makes reference to this
      series of Certificate or this Agreement, (ii) of which a Responsible Officer
      has
      actual knowledge, and (iii) which contains information sufficient to permit
      the
      Trustee to make a determination that the real property to which such document
      relates is a Mortgaged Property.

     

    (e) The
      Trustee shall not be personally liable with respect to any action taken,
      suffered or omitted to be taken by it in good faith in accordance with the
      direction of the Certificateholders of any Class holding Certificates which
      evidence, as to such Class, Percentage Interests aggregating not less than
      25%
      as to the time, method and place of conducting any proceeding for any remedy
      available to the Trustee or exercising any trust or power conferred upon the
      Trustee under this Agreement.

     

    (f) The
      Trustee shall not be required to perform services under this Agreement, or
      to
      expend or risk its own funds or otherwise incur financial liability for the
      performance of any of its duties hereunder or the exercise of any of its rights
      or powers if there is reasonable ground for believing that the timely payment
      of
      its fees and expenses or the repayment of such funds or adequate indemnity
      against such risk or liability is not reasonably assured to it, and none of
      the
      provisions contained in this Agreement shall in any event require the Trustee
      to
      perform, or be responsible for the manner of performance of, any of the
      obligations of the Master Servicer or the Servicer under this Agreement or
      the
      Servicing Agreement except during such time, if any, as the Trustee shall be
      the
      successor to, and be vested with the rights, duties, powers and privileges
      of,
      the Master Servicer in accordance with the terms of this Agreement.

     

    
      
        
        

      

      
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    (g) The
      Trustee shall not be held liable by reason of any insufficiency in the
      Collection Account or the Basis Risk Reserve Fund resulting from any investment
      loss on any Eligible Investment included therein (except to the extent that
      the
      Trustee is the obligor and has defaulted thereon).

     

    (h) Except
      as
      otherwise provided herein, the Trustee shall not have any duty (A) to undertake
      any recording, filing, or depositing of this Agreement or any agreement referred
      to herein or any financing statement or continuation statement evidencing a
      security interest, or to ensure the maintenance of any such recording or filing
      or depositing or to undertake any rerecording, refiling or redepositing of
      any
      such statement or agreement, (B) to see to any insurance or claim under any
      Insurance Policy, (C) to establish or maintain the payment or discharge of
      any
      tax, assessment, or other governmental charge or any lien or encumbrance of
      any
      kind owing with respect to, assessed or levied against, any part of the Trust
      Fund or the Supplemental Interest Trust other than from funds available in
      the
      Collection Account or the Certificate Account or (D) to confirm or verify the
      contents of any reports or certificates of the Master Servicer, the Servicer,
      the Swap Counterparty, the Depositor or the Credit Risk Manager delivered to
      the
      Trustee pursuant to this Agreement believed by the Trustee to be genuine and
      to
      have been signed or presented by the proper party or parties.

     

    (i) The
      Trustee shall not be liable in its individual capacity for an error of judgment
      made in good faith by a Responsible Officer or any other officer of the Trustee
      unless it shall be proved that the Trustee was negligent in ascertaining the
      pertinent facts.

     

    (j) Notwithstanding
      anything in this Agreement to the contrary, the Trustee shall not be liable
      for
      special, indirect or consequential losses or damages of any kind whatsoever
      (including, but not limited to, lost profits), even if the Trustee has been
      advised of the likelihood of such loss or damage and regardless of the form
      of
      action.

     

    (k) This
      Agreement shall not be construed to render the Trustee an agent of the Master
      Servicer or the Servicer.

     

    (l) On
      or
      before March 15 of each calendar year for so long as the Depositor is subject
      to
      Exchange Act reporting requirements for the Structured Asset Securities
      Corporation Mortgage Loan Trust 2006-S4, beginning with March 15, 2007, the
      Trustee shall deliver to the Sponsor, the Master Servicer and the Depositor
      a
      report regarding its assessment of compliance with the Relevant Servicing
      Criteria identified in Exhibit T hereto with respect to the Trustee, as of
      and
      for the period ending the end of the fiscal year of the Trust Fund. Each such
      report shall include (a) a statement of the party’s responsibility for assessing
      compliance with the Servicing Criteria applicable to such party, (b) a statement
      that such party used the criteria identified in Item 1122(d) of Regulation
      AB
      (Sec. 229.1122(d)) to assess compliance with the applicable Servicing Criteria,
      (c) disclosure of any material instance of noncompliance identified by such
      party and (d) a statement that a registered public accounting firm has issued
      an
      attestation report on such party’s assessment of compliance with the applicable
      Servicing Criteria, which report shall be delivered by the Trustee as provided
      in Section 6.01(m). In addition, on or before March 15th of each calendar year
      for so long as the Depositor is subject to Exchange Act reporting requirements
      for the Structured Asset Securities Corporation Mortgage Loan Trust 2006-S4,
      beginning with March 15, 2007, the Trustee shall, at its own expense, furnish
      or
      cause to be furnished to the Sponsor and the Depositor an assessment of
      compliance and attestation of any Subcontractor with respect to the
      Trustee.

     

    
      
        
        

      

      
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    (m) On
      or
      before March 15th of each calendar year for so long as the Depositor is subject
      to Exchange Act reporting requirements for the Structured Asset Securities
      Corporation Mortgage Loan Trust 2006-S4, beginning with March 15, 2007, the
      Trustee shall, at its own expense, cause a firm of independent public
      accountants (who may also render other services to Trustee), which is a member
      of the American Institute of Certified Public Accountants, to furnish to the
      Sponsor, the Master Servicer and the Depositor a report to the effect that
      such
      firm attests to, and reports on, the assessment made by such asserting party
      pursuant to Section 6.01(l) above, which report shall be made in accordance
      with
      standards for attestation engagements issued or adopted by the PCAOB.


     

    (n) For
      so
      long as the Depositor is subject to Exchange Act reporting requirements for
      the
      Structured Asset Securities Corporation Mortgage Loan Trust 2006-S4, the Trustee
      shall give prior written notice to the Sponsor, the Master Servicer and the
      Depositor of the appointment of any Subcontractor by it and a written
      description (in form and substance satisfactory to the Sponsor and the
      Depositor) of the role and function of each Subcontractor utilized by the
      Trustee, specifying (A) the identity of each such Subcontractor and (B) which
      elements of the servicing criteria set forth under Item 1122(d) of Regulation
      AB
      will be addressed in assessments of compliance and accountants’ attestations
      provided by each such Subcontractor.

     

    (o) For
      so
      long as the Depositor is subject to Exchange Act reporting requirements for
      the
      Structured Asset Securities Corporation Mortgage Loan Trust 2006-S4, the Trustee
      shall notify the Sponsor, the Master Servicer and the Depositor within three
      (3)
      Business Days of the related Distribution Date (i) of any legal proceedings
      pending against the Trustee of the type described in Item 1117 (Sec. 229.1117)
      of Regulation AB, (ii) of any merger, consolidation or sale of substantially
      all
      of the assets of the Trustee and (iii) if the Trustee shall become (but only
      to
      the extent not previously disclosed) at any time an affiliate of any of the
      parties listed on Exhibit V hereto or any of their affiliates. On or before
      March 1st of each year, the Depositor shall distribute the information in
      Exhibit V to the Trustee.

     

    (p) The
      Trustee agrees to indemnify the Depositor and the Master Servicer, and their
      respective directors, officers, employees and agents and the Trust Fund and
      hold
      each of them harmless from and against any losses, damages, penalties, fines,
      forfeitures, legal fees and expenses and related costs, judgments, and any
      other
      costs, fees and expenses that any of them may sustain arising out of or based
      upon any failure by the Trustee to comply with the provisions of Subsections
      6.01(l), (n) and (o) above; provided,
      however,
      that in
      no event shall the Trustee be liable for any special, consequential, indirect
      or
      punitive damages pursuant to this Section 6.01(p), even if advised of the
      possibility of such damages.

     

    (q) Notwithstanding
      anything in this Agreement, the Servicing Agreement or the Credit Risk
      Management Agreement to the contrary, the Trustee shall have no duty or
      obligation to enforce the Credit Risk Management Agreement or to supervise,
      monitor or oversee the activities of the Servicer under its Credit Risk
      Management Agreement with respect to any action taken or not taken by the
      Servicer at the direction of the Seller or pursuant to a recommendation of
      the
      Credit Risk Manager.

     

    
      
        
        

      

      
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              Section
                6.02 

            	
              Certain
                Matters Affecting the Trustee . 

            


    

     

    Except
      as
      otherwise provided in Section 6.01:

     

    (a) The
      Trustee may request, and may rely upon and shall be protected in acting or
      refraining from acting upon any resolution, Officer’s Certificate, certificate
      of auditors or any other certificate, statement, instrument, opinion, report,
      notice, request, consent, order, approval, bond or other paper or document
      believed by it to be genuine and to have been signed or presented by the proper
      party or parties;

     

    (b) The
      Trustee may consult with counsel and any advice of its counsel or Opinion of
      Counsel shall be full and complete authorization and protection in respect
      of
      any action taken or suffered or omitted by it hereunder in good faith and in
      accordance with such advice or Opinion of Counsel;

     

    (c) The
      Trustee shall not be personally liable for any action taken, suffered or omitted
      by it in good faith and reasonably believed by it to be authorized or within
      the
      discretion or rights or powers conferred upon it by this Agreement;

     

    (d) Unless
      an
      Event of Default shall have occurred and be continuing, the Trustee shall not
      be
      bound to make any investigation into the facts or matters stated in any
      resolution, certificate, statement, instrument, opinion, report, notice,
      request, consent, order, approval, bond or other paper or document (provided
      the same
      appears regular on its face), unless requested in writing to do so by the
      Holders of at least a majority in Class Principal Amount (or Percentage
      Interest) of each Class of Certificates or, if such Classes have been retired
      pursuant to a Section 7.01(c) Purchase Event, the LTURI-holder; provided,
      however,
      that,
      if the payment within a reasonable time to the Trustee of the costs, expenses
      or
      liabilities likely to be incurred by it in the making of such investigation
      is,
      in the opinion of the Trustee not reasonably assured to the Trustee by the
      security afforded to it by the terms of this Agreement, the Trustee may require
      reasonable indemnity against such expense or liability or payment of such
      estimated expenses from the Certificateholders, as applicable, as a condition
      to
      proceeding. The reasonable expense thereof shall be paid by the party requesting
      such investigation and if not reimbursed by the requesting party shall be
      reimbursed to the Trustee by the Trust Fund;

     

    (e) The
      Trustee may execute any of the trusts or powers hereunder or perform any duties
      hereunder either directly or by or through agents, custodians or attorneys,
      which agents, custodians or attorneys shall have any and all of the rights,
      powers, duties and obligations of the Trustee conferred on them by such
      appointment, provided
      that the
      Trustee shall continue to be responsible for its duties and obligations
      hereunder to the extent provided herein, and provided, further,
      that the
      Trustee shall not be responsible for any misconduct or negligence on the part
      of
      any such agent or attorney appointed with due care by the Trustee;

     

    (f) The
      Trustee shall not be under any obligation to exercise any of the trusts or
      powers vested in it by this Agreement or to institute, conduct or defend any
      litigation hereunder or in relation hereto, in each case at the request, order
      or direction of any of the Certificateholders pursuant to the provisions of
      this
      Agreement, unless such Certificateholders shall have offered to the Trustee
      reasonable security or indemnity against the costs, expenses and liabilities
      which may be incurred therein or thereby;

     

    
      
        
        

      

      
        100

        
          

        

      

      
        
        

      

    

     

    (g) The
      right
      of the Trustee to perform any discretionary act enumerated in this Agreement
      shall not be construed as a duty, and the Trustee shall not be answerable for
      other than its negligence or willful misconduct in the performance of such
      act;
      and

     

    (h) The
      Trustee shall not be required to give any bond or surety in respect of the
      execution of the Trust Fund or Supplemental Interest Trust created hereby or
      the
      powers granted hereunder.

     

    
      	 	
              Section
                6.03 

            	
              Trustee
                Not Liable for Certificates. 

            


    

     

    The
      Trustee makes no representations as to the validity or sufficiency of this
      Agreement, the Swap Agreement, the Certificates (other than the certificate
      of
      authentication on the Certificates) or the Lower Tier REMIC 1 Uncertificated
      Regular Interests or of any Mortgage Loan, or related document save that the
      Trustee represents that, assuming due execution and delivery by the other
      parties hereto, this Agreement has been duly authorized, executed and delivered
      by it and constitutes its valid and binding obligation, enforceable against
      it
      in accordance with its terms except that such enforceability may be subject
      to
      (A) applicable bankruptcy and insolvency laws and other similar laws affecting
      the enforcement of the rights of creditors generally, and (B) general principles
      of equity regardless of whether such enforcement is considered in a proceeding
      in equity or at law. The Trustee shall not be accountable for the use or
      application by the Depositor of funds paid to the Depositor in consideration
      of
      the assignment of the Mortgage Loans to the Trust Fund by the Depositor or
      for
      the use or application of any funds deposited into the Collection Account,
      the
      Certificate Account, any Escrow Account or any other fund or account maintained
      with respect to the Certificates. The Trustee shall not be responsible for
      the
      legality or validity of this Agreement
      or the
      Swap Agreement, or the validity, priority, perfection or sufficiency of the
      security for the Certificates or the Lower Tier REMIC 1 Uncertificated Regular
      Interests issued or intended to be issued hereunder. Except as otherwise
      provided herein, the Trustee shall have no responsibility for filing any
      financing or continuation statement in any public office at any time or to
      otherwise perfect or maintain the perfection of any security interest or lien
      granted to it hereunder or to record this Agreement.

     

    
      	 	
              Section
                6.04 

            	
              Trustee
                May Own Certificates. 

            


    

     

    The
      Trustee and any Affiliate or agent of the Trustee in its individual or any
      other
      capacity may become the owner or pledgee of Certificates and may transact
      banking and trust business with the other parties hereto and their Affiliates
      with the same rights it would have if it were not Trustee or such
      agent.

     

    
      	 	
              Section
                6.05 

            	
              Eligibility
                Requirements for Trustee. 

            


    

     

    The
      Trustee hereunder shall at all times be (i) an institution whose accounts are
      insured by the FDIC, (ii) a corporation or national banking association,
      organized and doing business under the laws of any State or the United States
      of
      America, authorized under such laws to exercise corporate trust powers, having
      a
      combined capital and surplus of not less than $50,000,000 and subject to
      supervision or examination by federal or state authority and (iii) not an
      Affiliate of the Master Servicer or the Servicer. In addition, the Trustee
      shall
      have a minimum short-term debt rating of at least “A-1”
      from S&P. If such corporation or national banking association publishes
      reports of condition at least annually, pursuant to law or to the requirements
      of the aforesaid supervising or examining authority, then, for the purposes
      of
      this Section, the combined capital and surplus of such corporation or national
      banking association shall be deemed to be its combined capital and surplus
      as
      set forth in its most recent report of condition so published. In case at any
      time the Trustee shall cease to be eligible in accordance with provisions of
      this Section, the Trustee shall resign immediately in the manner and with the
      effect specified in Section 6.06.

     

    
      
        
        

      

      
        101

        
          

        

      

      
        
        

      

    

     

    
      	 	
              Section
                6.06 

            	
              Resignation
                and Removal of Trustee. 

            


    

     

    (a) The
      Trustee may at any time resign and be discharged from the trust hereby created
      by giving written notice thereof to the Depositor, the Swap Counterparty and
      the
      Master Servicer. Upon receiving such notice of resignation, the Depositor will
      promptly appoint a successor trustee by written instrument, one copy of which
      instrument shall be delivered to the resigning Trustee, one copy to the
      successor trustee, and one copy to the Master Servicer. If no successor trustee
      shall have been so appointed and shall have accepted appointment within 30
      days
      after the giving of such notice of resignation, the resigning Trustee may
      petition any court of competent jurisdiction for the appointment of a successor
      trustee.

     

    (b) If
      at any
      time (i) the Trustee shall cease to be eligible in accordance with the
      provisions of Section 6.05 and shall fail to resign after written request
      therefor by the Depositor , (ii) the Trustee shall become incapable of acting,
      or shall be adjudged a bankrupt or insolvent, or a receiver of the Trustee
      of
      its property shall be appointed, or any public officer shall take charge or
      control of the Trustee or of its property or affairs for the purpose of
      rehabilitation, conservation or liquidation, (iii) a tax is imposed or
      threatened with respect to the Trust Fund by any state in which the Trustee
      or
      the Trust Fund held by the Trustee is located, (iv) the continued use of the
      Trustee would result in a downgrading of the rating by any Rating Agency of
      any
      Class of Certificates with a rating, (v) the Trustee shall fail to deliver
      the
      information or reports, assessments or attestations required pursuant to
      Sections 6.01(l) through (o) hereto or (vi) the Depositor desires to replace
      the
      Trustee with a successor trustee, then the Depositor shall remove the Trustee
      and the Depositor shall appoint a successor trustee acceptable to the Master
      Servicer by written instrument, one copy of which instrument shall be delivered
      to the Trustee so removed, one copy each to the successor trustee and one copy
      to the Master Servicer; provided,
      however, that
      if
      the Trustee is removed for the failure to provide the accountant’s attestation
      pursuant to Section 6.01(m) of this Agreement, the Trustee shall reimburse
      the
      Depositor for reasonable out-of-pocket costs incurred by the Depositor in
      providing for a successor Trustee.

     

    (c) The
      Holders of more than 50% of the Class Principal Amount (or Percentage Interest)
      of each Class of Certificates may at any time upon 30 days’ written notice to
      the Trustee and to the Depositor remove the Trustee by such written instrument,
      signed by such Holders or their attorney-in-fact duly authorized, one copy
      of
      which instrument shall be delivered to the Depositor, one copy to the Trustee
      and one copy to the Master Servicer; the Depositor shall thereupon appoint
      a
      successor trustee in accordance with this Section mutually acceptable to the
      Depositor and the Master Servicer.

     

    
      
        
        

      

      
        102

        
          

        

      

      
        
        

      

    

     

    (d) Any
      resignation or removal of the Trustee and appointment of a successor trustee
      pursuant to any of the provisions of this Section shall become effective upon
      (i) the payment of all unpaid amounts owed to the Trustee and (ii) the
      acceptance of appointment by the successor trustee as provided in Section
      6.07.

     

    
      	 	
              Section
                6.07 

            	
              Successor
                Trustee. 

            


    

     

    (a) Any
      successor trustee appointed as provided in Section 6.06 shall execute,
      acknowledge and deliver to the Depositor, the Master Servicer, the Swap
      Counterparty and to its predecessor trustee an instrument accepting such
      appointment hereunder, and thereupon the resignation or removal of the
      predecessor trustee shall become effective and such successor trustee without
      any further act, deed or conveyance, shall become fully vested with all the
      rights, powers, duties and obligations of its predecessor hereunder, with like
      effect as if originally named as trustee herein. The predecessor trustee (or
      its
      custodian) shall deliver to any successor trustee (or assign to the Trustee
      its
      interest under each Custodial Agreement, to the extent permitted thereunder)
      all
      Mortgage Files and documents and statements related to each Mortgage File held
      by it hereunder, and shall duly assign, transfer, deliver and pay over to the
      successor trustee the entire Trust Fund, together with all necessary instruments
      of transfer and assignment or other documents properly executed necessary to
      effect such transfer and such of the records or copies thereof maintained by
      the
      predecessor trustee in the administration hereof as may be requested by the
      successor trustee and shall thereupon be discharged from all duties and
      responsibilities under this Agreement. In addition, the Master Servicer and
      the
      predecessor trustee shall execute and deliver such other instruments and do
      such
      other things as may reasonably be required to more fully and certainly vest
      and
      confirm in the successor trustee all such rights, powers, duties and
      obligations. 

     

    (b) No
      successor trustee shall accept appointment as provided in this Section unless
      at
      the time of such appointment such successor trustee shall be eligible under
      the
      provisions of Section 6.05.

     

    (c) Upon
      acceptance of appointment by a successor trustee as provided in this Section,
      the predecessor trustee shall mail notice of the succession of such trustee
      hereunder to all Holders of Certificates at their addresses as shown in the
      Certificate Register and to any Rating Agency. The expenses of such mailing
      shall be borne by the predecessor trustee.

     

    (d) Upon
      the
      resignation or removal of the Trustee pursuant to this Section 6.07, the Trustee
      shall deliver the amounts held in its possession for the benefit of the
      Certificateholders to the successor trustee or the successor trustee’s designee
      upon the appointment of such successor trustee.

     

    
      	 	
              Section
                6.08 

            	
              Merger
                or Consolidation of Trustee. 

            


    

     

    Any
      Person into which the Trustee may be merged or with which it may be
      consolidated, or any Person resulting from any merger, conversion or
      consolidation to which the Trustee shall be a party, or any Persons succeeding
      to the corporate trust business of the Trustee, shall be the successor to the
      Trustee hereunder, without the execution or filing of any paper or any further
      act on the part of any of the parties hereto, anything herein to the contrary
      notwithstanding, provided
      that
      such Person shall be eligible under the provisions of Section 6.05. Unless
      and
      until a Form 15 suspension notice shall have been filed, as a condition to
      the
      succession to the Trustee under this Agreement by any Person (i) into which
      the
      Trustee may be merged or consolidated, or (ii) which may be appointed as a
      successor to the Trustee, the Trustee shall notify the Sponsor, the Master
      Servicer and the Depositor, at least 15 calendar days prior to the effective
      date of such succession or appointment, of such succession or appointment and
      shall furnish to the Sponsor, the Master Servicer and the Depositor in writing
      and in form and substance reasonably satisfactory to the Sponsor, the Master
      Servicer and the Depositor, all information reasonably necessary for the Trustee
      to accurately and timely report, pursuant to Section 6.20, the event under
      Item
      6.02 of Form 8-K pursuant to the Exchange Act (if such reports under the
      Exchange Act are required to be filed under the Exchange Act). 

     

    
      
        
        

      

      
        103

        
          

        

      

      
        
        

      

    

     

    
      	 	
              Section
                6.09 

            	
              Appointment
                of Co-Trustee, Separate Trustee or Custodian. 

            


    

     

    (a) Notwithstanding
      any other provisions hereof, at any time, the Trustee, the Depositor or the
      Certificateholders evidencing more than 50% of the Class Principal Amount (or
      Percentage Interest) of every Class of Certificates shall
      have the power from time to time to appoint one or more Persons, approved by
      the
      Trustee, to act either as co-trustees jointly with the Trustee, or as separate
      trustees, or as custodians, for the purpose of holding title to, foreclosing
      or
      otherwise taking action with respect to any Mortgage Loan outside the state
      where the Trustee has its principal place of business where such separate
      trustee or co-trustee is necessary or advisable (or the Trustee has been advised
      by the Master Servicer that such separate trustee or co-trustee is necessary
      or
      advisable) under the laws of any state in which a property securing a Mortgage
      Loan is located or for the purpose of otherwise conforming to any legal
      requirement, restriction or condition in any state in which a property securing
      a Mortgage Loan is located or in any state in which any portion of the Trust
      Fund is located. The separate Trustees, co-trustees or custodians so appointed
      shall be trustees or custodians for the benefit of all the Certificateholders
      and shall have such powers, rights and remedies as shall be specified in the
      instrument of appointment; provided,
      however,
      that no
      such appointment shall, or shall be deemed to, constitute the appointee an
      agent
      of the Trustee. The Trustee shall not be responsible for any action or omission
      of any separate trustee, co-trustee or custodian. Notwithstanding the foregoing,
      at any time during the period that a Form 10-K is being filed with respect
      to
      the Trust Fund in accordance with the Exchange Act and the rules and regulations
      of the Commission, no such co-custodian or co-trustee shall be vested with
      any
      powers, rights and remedies under this Agreement unless such party has agreed
      to
      comply with all Regulation AB requirements set forth under this Agreement or
      the
      related Custodial Agreement, as applicable.

     

    (b) Every
      separate trustee, co-trustee and custodian shall, to the extent permitted by
      law, be appointed and act subject to the following provisions and
      conditions:

     

    (i) all
      powers, duties, obligations and rights conferred upon the Trustee in respect
      of
      the receipt, custody and payment of monies shall be exercised solely by the
      Trustee;

     

    (ii) all
      other
      rights, powers, duties and obligations conferred or imposed upon the Trustee
      shall be conferred or imposed upon and exercised or performed by the Trustee
      and
      such separate trustee, co-trustee, or custodian jointly, except to the extent
      that under any law of any jurisdiction in which any particular act or acts
      are
      to be performed the Trustee shall be incompetent or unqualified to perform
      such
      act or acts, in which event such rights, powers, duties and obligations,
      including the holding of title to the Trust Fund or any portion thereof in
      any
      such jurisdiction, shall be exercised and performed by such separate trustee,
      co-trustee, or custodian;

     

    
      
        
        

      

      
        104

        
          

        

      

      
        
        

      

    

     

    (iii) no
      trustee or custodian hereunder shall be personally liable by reason of any
      act
      or omission of any other trustee or custodian hereunder; and

     

    (iv) the
      Trustee or the Certificateholders evidencing more than 50% of the Aggregate
      Voting Interests of the Certificates may at any time accept the resignation
      of
      or remove any separate trustee, co-trustee or custodian, so appointed by it
      or
      them, if such resignation or removal does not violate the other terms of this
      Agreement.

     

    (c) Any
      notice, request or other writing given to the Trustee shall be deemed to have
      been given to each of the then separate trustees and co-trustees, as effectively
      as if given to each of them. Every instrument appointing any separate trustee,
      co-trustee or custodian shall refer to this Agreement and the conditions of
      this
      Article VI. Each separate trustee and co-trustee, upon its acceptance of the
      trusts conferred, shall be vested with the estates or property specified in
      its
      instrument of appointment, either jointly with the Trustee or separately, as
      may
      be provided therein, subject to all the provisions of this Agreement,
      specifically including every provision of this Agreement relating to the conduct
      of, affecting the liability of, or affording protection to, the Trustee. Every
      such instrument shall be filed with the Trustee and a copy given to the Master
      Servicer.

     

    (d) Any
      separate trustee, co-trustee or custodian may, at any time, constitute the
      Trustee its agent or attorney-in-fact with full power and authority, to the
      extent not prohibited by law, to do any lawful act under or in respect of this
      Agreement on its behalf and in its name. If any separate trustee, co-trustee
      or
      custodian shall die, become incapable of acting, resign or be removed, all
      of
      its estates, properties, rights, remedies and trusts shall vest in and be
      exercised by the Trustee, to the extent permitted by law, without the
      appointment of a new or successor trustee.

     

    (e) No
      separate trustee, co-trustee or custodian hereunder shall be required to meet
      the terms of eligibility as a successor trustee under Section 6.05 hereunder
      and
      no notice to Certificateholders of the appointment shall be required under
      Section 6.07 hereof.

     

    (f) The
      Trustee agrees to instruct the co-trustees, if any, to the extent necessary
      to
      fulfill the Trustee’s obligations hereunder.

     

    (g) The
      Trustee shall pay the reasonable compensation of the co-trustees requested
      by
      the Trustee to be so appointed (which compensation shall not reduce any
      compensation payable to the Trustee ) and, if paid by the Trustee, shall be
      a
      reimbursable expense pursuant to Section 6.12.

     

    
      	 	
              Section
                6.10 

            	
              Authenticating
                Agents. 

            


    

     

    (a) The
      Trustee may appoint one or more Authenticating Agents which shall be authorized
      to act on behalf of the Trustee in authenticating Certificates. Wherever
      reference is made in this Agreement to the authentication of Certificates by
      the
      Trustee or the Trustee’s certificate of authentication, such reference shall be
      deemed to include authentication on behalf of the Trustee by an Authenticating
      Agent and a certificate of authentication executed on behalf of the Trustee
      by
      an Authenticating Agent. Each Authenticating Agent must be a corporation
      organized and doing business under the laws of the United States of America
      or
      of any state, having a combined capital and surplus of at least $15,000,000,
      authorized under such laws to do a trust business and subject to supervision
      or
      examination by federal or state authorities.

     

    
      
        
        

      

      
        105

        
          

        

      

      
        
        

      

    

     

    (b) Any
      Person into which any Authenticating Agent may be merged or converted or with
      which it may be consolidated, or any Person resulting from any merger,
      conversion or consolidation to which any Authenticating Agent shall be a party,
      or any Person succeeding to the corporate agency business of any Authenticating
      Agent, shall continue to be the Authenticating Agent without the execution
      or
      filing of any paper or any further act on the part of the Trustee or the
      Authenticating Agent.

     

    (c) Any
      Authenticating Agent may at any time resign by giving at least 30 days’ advance
      written notice of resignation to the Trustee and the Depositor. The Trustee
      may
      at any time terminate the agency of any Authenticating Agent by giving written
      notice of termination to such Authenticating Agent and the Depositor. Upon
      receiving a notice of resignation or upon such a termination, or in case at
      any
      time any Authenticating Agent shall cease to be eligible in accordance with
      the
      provisions of this Section 6.10, the Trustee may appoint a successor
      Authenticating Agent, shall give written notice of such appointment to the
      Depositor and shall mail notice of such appointment to all Holders of
      Certificates. Any successor Authenticating Agent upon acceptance of its
      appointment hereunder shall become vested with all the rights, powers, duties
      and responsibilities of its predecessor hereunder, with like effect as if
      originally named as Authenticating Agent. No successor Authenticating Agent
      shall be appointed unless eligible under the provisions of this Section 6.10.
      No
      Authenticating Agent shall have responsibility or liability for any action
      taken
      by it as such at the direction of the Trustee. Any Authenticating Agent shall
      be
      entitled to reasonable compensation for its services and, if paid by the
      Trustee, it shall be a reimbursable expense pursuant to Section
      6.12.

     

    
      	 	
              Section
                6.11 

            	
              Indemnification
                of Trustee. 

            


    

     

    The
      Trustee and its directors, officers, employees and agents shall be entitled
      to
      indemnification from the Trust Fund for any loss, liability or expense incurred
      in connection with any legal proceeding or incurred without negligence or
      willful misconduct on their part arising out of, or in connection with, the
      acceptance or administration of the trusts created hereunder or in connection
      with the performance of their duties hereunder or under the Swap Agreement,
      the
      Mortgage Loan Sale Agreement, the Servicing Agreement or each Custodial
      Agreement, including any applicable fees and expenses payable pursuant to
      Section 6.12 and the costs and expenses of defending themselves against any
      claim in connection with the exercise or performance of any of their powers
      or
      duties hereunder, provided
      that:

     

    (i) with
      respect to any such claim, the Trustee shall have given the Depositor, the
      Master Servicer and the Holders written notice thereof promptly after a
      Responsible Officer of the Trustee shall have knowledge thereof, provided
      that the
      failure to provide such prompt written notice shall not affect the Trustee’s
      right to indemnification hereunder;

     

    
      
        
        

      

      
        106

        
          

        

      

      
        
        

      

    

     

    (ii) while
      maintaining control over its own defense, the Trustee shall cooperate and
      consult fully with the Depositor in preparing such defense; and

     

    (iii) notwithstanding
      anything to the contrary in this Section 6.11, the Trust Fund shall not be
      liable for settlement of any such claim by the Trustee entered into without
      the
      prior consent of the Depositor, which consent shall not be unreasonably
      withheld.

     

    The
      Trustee shall be further indemnified by the Seller for and held harmless
      against, any loss, liability or expense arising out of, or in connection with,
      the provisions set forth in the fourth paragraph of Section 2.01(a) hereof,
      including, without limitation, all costs, liabilities and expenses (including
      reasonable legal fees and expenses) of investigating and defending itself
      against any claim, action or proceeding, pending or threatened, relating to
      the
      provisions of such paragraph.

     

    The
      provisions of this Section 6.11 shall survive any termination of this Agreement
      and the resignation or removal of the Trustee and shall be construed to include,
      but not be limited to any loss, liability or expense under any environmental
      law.

     

    
      	 	
              Section
                6.12 

            	
              Fees
                and Expenses of Trustee and Custodians. 

            


    

     

    The
      Trustee shall be entitled to receive, and is authorized to pay itself, any
      investment income and earnings on the Certificate Account. The Trustee shall
      be
      entitled to reimbursement of all reasonable expenses, disbursements and advances
      incurred or made by the Trustee in accordance with this Agreement (including
      fees and expenses of its counsel and all persons not regularly in its employment
      and any amounts described in Section 10.01 to which the Trustee is entitled
      as
      provided therein), except for expenses, disbursements and advances that either
      (i) do not constitute “unanticipated
      expenses” within the meaning of Treasury Regulation Section 1.860G-1(b)(3)(ii)
      or (ii) arise from its negligence, bad faith or willful misconduct. Each
      Custodian shall receive compensation and reimbursement or payment of its
      expenses under the related Custodial Agreement as provided therein; provided
      that to
      the extent required under Section 6 or Section 20 of the Custodial Agreement,
      the Trustee is hereby authorized to pay such compensation or reimbursement
      from
      amounts on deposit in the Certificate Account prior to any distributions to
      Certificateholders pursuant to Section 5.02 hereof. 

     

    
      	 	
              Section
                6.13 

            	
              Collection
                of Monies. 

            


    

     

    Except
      as
      otherwise expressly provided in this Agreement, the Trustee may demand payment
      or delivery of, and shall receive and collect, all money and other property
      payable to or receivable by the Trustee pursuant to this Agreement. The Trustee
      shall hold all such money and property received by it as part of the Trust
      Fund
      and shall distribute it as provided in this Agreement. If the Trustee shall
      not
      have timely received amounts to be remitted with respect to the Mortgage Loans
      from the Master Servicer, the Trustee shall request the Master Servicer to
      make
      such distribution as promptly as practicable or legally permitted. If the
      Trustee shall subsequently receive any such amounts, it may withdraw such
      request.

     

    
      
        
        

      

      
        107

        
          

        

      

      
        
        

      

    

     

    
      	 	
              Section
                6.14 

            	
              Events
                of Default; Trustee To Act; Appointment of Successor. 

            


    

     

    (a) The
      occurrence of any one or more of the following events shall constitute an “Event
      of Default”:

     

    (i) Any
      failure by the Master Servicer to furnish to the Trustee the Mortgage Loan
      data
      sufficient to prepare the reports described in Section 4.03(a) (other than
      with
      respect to the information referred to in clauses (xvi), (xviii) and (xix)
      of
      such Section 4.03(a)) which continues unremedied for a period of two (2)
      Business Days after the date upon which written notice of such failure shall
      have been given to such Master Servicer by the Trustee, or to such Master
      Servicer and the Trustee by the Holders of not less than 25% of the Class
      Principal Amount of each Class of Certificates affected thereby; or

     

    (ii) Any
      failure by the Master Servicer to duly perform, within the required time period
      and without notice, its obligations to provide any certifications required
      pursuant to Sections 9.25 or 9.26, which failure continues unremedied for a
      period of five (5) days from the date of delivery required with respect to
      such
      certification; or

     

    (iii) Except
      with respect to those items listed in clause (ii) above, any failure by the
      Master Servicer to duly perform, within the required time period, without notice
      or grace period, its obligations to provide any information, data or materials
      required to be provided hereunder pursuant to Sections 9.23 and 9.29(b),
      including any items required to be included in any Exchange Act report;
      or

     

    (iv) Any
      failure on the part of the Master Servicer duly to observe or perform in any
      material respect any other of the covenants or agreements on the part of the
      Master Servicer contained in this Agreement which continues unremedied for
      a
      period of 30 days after the date on which written notice of such failure,
      requiring the same to be remedied, shall have been given to the Master Servicer
      by the Trustee, or to the Master Servicer and the Trustee by the Holders of
      more
      than 50% of the Aggregate Voting Interests of the Certificates; or

     

    (v) A
      decree
      or order of a court or agency or supervisory authority having jurisdiction
      for
      the appointment of a conservator or receiver or liquidator in any insolvency,
      readjustment of debt, marshalling of assets and liabilities or similar
      proceedings, or for the winding-up or liquidation of its affairs, shall have
      been entered against the Master Servicer, and such decree or order shall have
      remained in force undischarged or unstayed for a period of 60 days or any Rating
      Agency reduces or withdraws or threatens to reduce or withdraw the rating of
      the
      Certificates because of the financial condition or loan servicing capability
      of
      such Master Servicer; or

     

    (vi) The
      Master Servicer shall consent to the appointment of a conservator or receiver
      or
      liquidator in any insolvency, readjustment of debt, marshalling of assets and
      liabilities, voluntary liquidation or similar proceedings of or relating to
      the
      Master Servicer or of or relating to all or substantially all of its property;
      or

     

    (vii) The
      Master Servicer shall admit in writing its inability to pay its debts generally
      as they become due, file a petition to take advantage of any applicable
      insolvency or reorganization statute, make an assignment for the benefit of
      its
      creditors or voluntarily suspend payment of its obligations; or

     

    
      
        
        

      

      
        108

        
          

        

      

      
        
        

      

    

     

    (viii) The
      Master Servicer shall be dissolved, or shall dispose of all or substantially
      all
      of its assets, or consolidate with or merge into another entity or shall permit
      another entity to consolidate or merge into it, such that the resulting entity
      does not meet the criteria for a successor servicer as specified in Section
      9.27
      hereof; or

     

    (ix) If
      a
      representation or warranty set forth in Section 9.14 hereof shall prove to
      be
      incorrect as of the time made in any respect that materially and adversely
      affects the interests of the Certificateholders, and the circumstance or
      condition in respect of which such representation or warranty was incorrect
      shall not have been eliminated or cured within 30 days after the date on which
      written notice of such incorrect representation or warranty shall have been
      given to the Master Servicer by the Trustee, or to the Master Servicer and
      the
      Trustee by the Holders of more than 50% of the Aggregate Voting Interests of
      the
      Certificates; or

     

    (x) A
      sale or
      pledge of any of the rights of the Master Servicer hereunder or an assignment
      of
      this Agreement by the Master Servicer or a delegation of the rights or duties
      of
      the Master Servicer hereunder shall have occurred in any manner not otherwise
      permitted hereunder and without the prior written consent of the Trustee,
      Certificateholders holding more than 50% of the Aggregate Voting Interests
      of
      the Certificates; or

     

    (xi) The
      Master Servicer has notice or actual knowledge that the Servicer at any time
      is
      not either a Fannie Mae- or Freddie Mac- approved Seller/Servicer, and the
      Master Servicer has not terminated the rights and obligations of the Servicer
      under the Servicing Agreement and replaced the Servicer with a Fannie Mae-
      or
      Freddie Mac -approved servicer within 60 days of the date the Master Servicer
      receives such notice or acquires such actual knowledge; or

     

    (xii) After
      receipt of notice from the Trustee, any failure of the Master Servicer to remit
      to the Trustee any payment required to be made to the Trustee for the benefit
      of
      Certificateholders under the terms of this Agreement, including any Advance,
      on
      any Master Servicer Remittance Date which failure continues unremedied for
      a
      period of one Business Day (but in no event later than 12:00 p.m. New York
      City
      time on the related Distribution Date) after the date upon which notice of
      such
      failure shall have been given to the Master Servicer by the
      Trustee.

     

    If
      an
      Event of Default described in clauses (i) through (xii) of this Section shall
      occur, then, in each and every case, subject to applicable law, so long as
      any
      such Event of Default shall not have been remedied within any period of time
      prescribed by this Section, the Trustee, by notice in writing to the Master
      Servicer may, and shall, if so directed by Certificateholders evidencing more
      than 50% of the Class Principal Amount of each Class of Certificates, terminate
      all of the rights and obligations of the Master Servicer hereunder and in and
      to
      the Mortgage Loans and the proceeds thereof. If an Event of Default described
      in
      clause (xii) of this Section shall occur, then, in each and every case, subject
      to applicable law,
      so long
      as such Event of Default shall not have been remedied within the time period
      prescribed by clause (xii) of this Section 6.14, the
      Trustee, by notice in writing to the Master Servicer, shall promptly terminate
      all of the rights and obligations of the Master Servicer hereunder and in and
      to
      the Mortgage Loans and the proceeds thereof. On or after the receipt by the
      Master Servicer of such written notice, all authority and power of the Master
      Servicer, and only in its capacity as Master Servicer under this Agreement,
      whether with respect to the Mortgage Loans or otherwise, shall pass to and
      be
      vested in the Trustee and pursuant to and under the terms of this Agreement;
      provided,
      however,
      the
      parties acknowledge that notwithstanding the preceding sentence there may be
      a
      transition period, not to exceed 90 days, in order to effect the transfer of
      the
      Master Servicing obligations to the Trustee. The Trustee is hereby authorized
      and empowered to execute and deliver, on behalf of the defaulting Master
      Servicer as attorney-in-fact or otherwise, any and all documents and other
      instruments, and to do or accomplish all other acts or things necessary or
      appropriate to effect the purposes of such notice of termination, whether to
      complete the transfer and endorsement or assignment of the Mortgage Loans and
      related documents or otherwise. The defaulting Master Servicer agrees to
      cooperate with the Trustee in effecting the termination of the defaulting Master
      Servicer’s responsibilities and rights hereunder as Master Servicer including,
      without limitation, notifying the Servicer of the assignment of the master
      servicing function and providing the Trustee or its designee all documents
      and
      records in electronic or other form reasonably requested by it to enable the
      Trustee or its designee to assume the defaulting Master Servicer’s functions
      hereunder and the transfer to the Trustee or its designee for administration
      by
      it of all amounts which shall at the time be or should have been deposited
      by
      the defaulting Master Servicer in the Collection Account maintained by such
      defaulting Master Servicer and any other account or fund maintained with respect
      to the Certificates or thereafter received with respect to the Mortgage Loans.
      The Master Servicer being terminated (or the Trust Fund, if the Master Servicer
      is unable to fulfill its obligations hereunder) as a result of an Event of
      Default shall bear all costs of a master servicing transfer, including but
      not
      limited to those of the Trustee reasonably allocable to specific employees
      and
      overhead, legal fees and expenses, accounting and financial consulting fees
      and
      expenses, and costs of amending the Agreement, if necessary.

     

    
      
        
        

      

      
        109

        
          

        

      

      
        
        

      

    

     

    The
      Trustee shall be entitled to be reimbursed from the Master Servicer (or by
      the
      Trust Fund, if the Master Servicer is unable to fulfill its obligations
      hereunder) for all costs associated with the transfer of master servicing from
      the predecessor Master Servicer, including, without limitation, any costs or
      expenses associated with the complete transfer of all master servicing data
      and
      the completion, correction or manipulation of such servicing data as may be
      required by the Trustee to correct any errors or insufficiencies in the master
      servicing data or otherwise to enable the Trustee to master service the Mortgage
      Loans properly and effectively. If the terminated Master Servicer does not
      pay
      such reimbursement within thirty (30) days of its receipt of an invoice
      therefor, such reimbursement shall be an expense of the Trust Fund and the
      Trustee shall be entitled to withdraw such reimbursement from amounts on deposit
      in the Certificate Account pursuant to Section 4.04(b); provided
      that the
      terminated Master Servicer shall reimburse the Trust Fund for any such expense
      incurred by the Trust Fund; and provided,
      further,
      that
      the Trustee shall decide whether and to what extent it is in the best interest
      of the Certificateholders to pursue any remedy against any party obligated
      to
      make such reimbursement.

     

    Notwithstanding
      the termination of its activities as Master Servicer, each terminated Master
      Servicer shall continue to be entitled to reimbursement to the extent provided
      in Section 4.02 to the extent such reimbursement relates to the period prior
      to
      such Master Servicer’s termination.

     

    
      
        
        

      

      
        110

        
          

        

      

      
        
        

      

    

     

    If
      any
      Event of Default shall occur of which a Responsible Officer of the Trustee
      has
      actual knowledge, the Trustee shall promptly notify the Swap Counterparty and
      each Rating Agency of the nature and extent of such Event of Default. The
      Trustee shall immediately give written notice to the Master Servicer upon the
      Master Servicer’s failure to remit funds on the Master Servicer Remittance
      Date.

     

    (b) Within
      90
      days of the time the Master Servicer receives a notice of termination from
      the
      Trustee pursuant to Section 6.14(a) or the Trustee receives the resignation
      of
      the Master Servicer evidenced by an Opinion of Counsel pursuant to Section
      9.28,
      the Trustee, unless another master servicer shall have been appointed, shall
      be
      the successor in all respects to the Master Servicer in its capacity as such
      under this Agreement and the transactions set forth or provided for herein
      and
      shall have all the rights and powers and be subject to all the responsibilities,
      duties and liabilities relating thereto and arising thereafter placed on the
      Master Servicer hereunder, including the obligation to make Advances;
provided,
      however,
      that any
      failure to perform such duties or responsibilities caused by the Master
      Servicer’s failure to provide information required by this Agreement shall not
      be considered a default by the Trustee hereunder. In addition, the Trustee
      shall
      have no responsibility for any act or omission of the Master Servicer prior
      to
      the issuance of any notice of termination and within a period of time not to
      exceed 90 days after the issuance of written notice of termination pursuant
      to
      Section 6.14(a) or Section 9.28 or for any breach of representation or warranty
      by such predecessor Master Servicer. The Trustee shall have no liability
      relating to the representations and warranties of the Master Servicer set forth
      in Section 9.14. In the Trustee’s capacity as such successor, the Trustee shall
      have the same limitations on liability herein granted to the Master Servicer.
      As
      compensation therefor, the Trustee shall be entitled to receive all compensation
      payable to the Master Servicer under this Agreement, including the Master
      Servicing Fee.

     

    (c) Notwithstanding
      the above, the Trustee may, if it shall be unwilling to continue to so act,
      or
      shall, if it is unable to so act, petition a court of competent jurisdiction
      to
      appoint, or appoint on its own behalf any established housing and home finance
      institution servicer, master servicer, servicing or mortgage servicing
      institution having a net worth of not less than $15,000,000 and meeting such
      other standards for a successor master servicer as are set forth in this
      Agreement, as the successor to such Master Servicer in the assumption of all
      of
      the responsibilities, duties or liabilities of the Master Servicer hereunder.
      Any entity designated by the Trustee as a successor master servicer may be
      an
      Affiliate of the Trustee; provided,
      however,
      that,
      unless such Affiliate meets the net worth requirements and other standards
      set
      forth herein for a successor master servicer, or the Trustee, in its individual
      capacity shall agree, at the time of such designation, to be and remain liable
      to the Trust Fund for such Affiliate’s actions and omissions in performing its
      duties hereunder. In connection with such appointment and assumption, the
      Trustee may make such arrangements for the compensation of such successor out
      of
      payments on Mortgage Loans as it and such successor shall agree; provided,
      however,
      that no
      such compensation shall be in excess of that permitted to the Master Servicer
      hereunder. The Trustee and such successor shall take such actions, consistent
      with this Agreement, as shall be necessary to effectuate any such succession
      and
      may make other arrangements with respect to the servicing to be conducted
      hereunder which are not inconsistent herewith. The Master Servicer shall
      cooperate with the Trustee and any successor master servicer in effecting the
      termination of the Master Servicer’s responsibilities and rights hereunder
      including, without limitation, notifying Mortgagors of the assignment of the
      master servicing functions and providing the Trustee and successor master
      servicer, as applicable, all documents and records in electronic or other form
      reasonably requested by it to enable it to assume the Master Servicer’s
      functions hereunder and the transfer to the Trustee or such successor master
      servicer, as applicable, all amounts which shall at the time be or should have
      been deposited by the Master Servicer in the Collection Account and any other
      account or fund maintained with respect to the Certificates or the Lower Tier
      REMIC 1 Uncertificated Regular Interests or thereafter be received with
      respect to the Mortgage Loans. Neither the Trustee nor any other successor
      master servicer shall be deemed to be in default hereunder by reason of any
      failure to make, or any delay in making, any distribution hereunder or any
      portion thereof caused by (i) the failure of the Master Servicer to deliver,
      or
      any delay in delivering, cash, documents or records to it, (ii) the failure
      of
      the Master Servicer to cooperate as required by this Agreement, (iii) the
      failure of the Master Servicer to deliver the Mortgage Loan data to the Trustee
      as required by this Agreement or (iv) restrictions imposed by any regulatory
      authority having jurisdiction over the Master Servicer. 

     

    
      
        
        

      

      
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              Section
                6.15 

            	
              Additional
                Remedies of Trustee Upon Event of Default. 

            


    

     

    During
      the continuance of any Event of Default, so long as such Event of Default shall
      not have been remedied, the Trustee, in addition to the rights specified in
      Section 6.14, shall have the right, in its own name and as trustee of an express
      trust, to take all actions now or hereafter existing at law, in equity or by
      statute to enforce its rights and remedies and to protect the interests, and
      enforce the rights and remedies, of the Certificateholders (including the
      institution and prosecution of all judicial, administrative and other
      proceedings and the filings of proofs of claim and debt in connection
      therewith). Except as otherwise expressly provided in this Agreement, no remedy
      provided for by this Agreement shall be exclusive of any other remedy, and
      each
      and every remedy shall be cumulative and in addition to any other remedy, and
      no
      delay or omission to exercise any right or remedy shall impair any such right
      or
      remedy or shall be deemed to be a waiver of any Event of Default.

     

    
      	 	
              Section
                6.16 

            	
              Waiver
                of Defaults. 

            


    

     

    More
      than
      50% of the Aggregate Voting Interests of Certificateholders may waive any
      default or Event of Default by the Master Servicer in the performance of its
      obligations hereunder, except that a default in the making of any required
      deposit to the Certificate Account that would result in a failure of the Trustee
      to make any required payment of principal of or interest on the Certificates
      may
      only be waived with the consent of 100% of the affected Certificateholders.
      Upon
      any such waiver of a past default, such default shall cease to exist, and any
      Event of Default arising therefrom shall be deemed to have been remedied for
      every purpose of this Agreement. No such waiver shall extend to any subsequent
      or other default or impair any right consequent thereon except to the extent
      expressly so waived.

     

    
      	 	
              Section
                6.17 

            	
              Notification
                to Holders. 

            


    

     

    Upon
      termination of the Master Servicer or appointment of a successor to the Master
      Servicer, in each case as provided herein, the Trustee shall promptly mail
      notice thereof by first class mail to the Certificateholders at their respective
      addresses appearing on the Certificate Register and the Swap Counterparty.
      The
      Trustee shall also, within 45 days after the occurrence of any Event of Default
      known to a Responsible Officer of the Trustee, give written notice thereof
      to
      the
      Certificateholders and the Swap Counterparty, unless such Event of Default
      shall
      have been cured or waived prior to the issuance of such notice and within such
      45-day period.

     

    
      
        
        

      

      
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              Section
                6.18 

            	
              Directions
                by Certificateholders and Duties of Trustee During Event of
                Default. 

            


    

     

    Subject
      to the provisions of Section 8.01 hereof, during the continuance of any Event
      of
      Default, Holders of Certificates evidencing not less than 25% of the Class
      Principal Amount (or Percentage Interest) of each Class of Certificates affected
      thereby may direct the time, method and place of conducting any proceeding
      for
      any remedy available to the Trustee, or exercising any trust or power conferred
      upon the Trustee, under this Agreement; provided,
      however,
      that the
      Trustee shall be under no obligation to pursue any such remedy, or to exercise
      any of the trusts or powers vested in it by this Agreement (including, without
      limitation, (i) the conducting or defending of any administrative action or
      litigation hereunder or in relation hereto and (ii) the terminating of the
      Master Servicer or any successor master servicer from its rights and duties
      as
      master servicer hereunder) at the request, order or direction of any of the
      Certificateholders, unless such Certificateholders shall have offered to the
      Trustee reasonable security or indemnity against the cost, expenses and
      liabilities which may be incurred therein or thereby; and provided, further,
      that
      subject to the provisions of Section 8.01, the Trustee shall have the right
      to
      decline to follow any such direction if the Trustee, in accordance with an
      Opinion of Counsel, determines that the action or proceeding so directed may
      not
      lawfully be taken or if the Trustee in good faith determines that the action
      or
      proceeding so directed would involve it in personal liability for which it
      is
      not indemnified to its satisfaction or be unjustly prejudicial to the
      non-assenting Certificateholders.

     

    
      	 	
              Section
                6.19 

            	
              Action
                Upon Certain Failures of the Master Servicer and Upon Event of
                Default. 

            


    

     

    In
      the
      event that a Responsible Officer of the Trustee shall have actual knowledge
      of
      any action or inaction of the Master Servicer that would become an Event of
      Default upon the Master Servicer’s
      failure to remedy the same after notice, the Trustee shall give notice thereof
      to the Master Servicer and the Swap Counterparty. For all purposes of this
      Agreement, in the absence of actual knowledge by a Responsible Officer of the
      Trustee, the Trustee shall not be deemed to have knowledge of any failure of
      the
      Master Servicer or any other Event of Default unless notified in writing by
      the
      Depositor, the Master Servicer, the Swap Counterparty or the
      Certificateholders.

     

    
      	 	
              Section
                6.20 

            	
              Preparation
                of Tax Returns and Other Reports. 

            


    

     

    (a) The
      Trustee shall prepare or cause to be prepared on behalf of the Trust Fund,
      based
      upon information calculated in accordance with this Agreement pursuant to
      instructions given by the Depositor, and the Trustee shall file federal tax
      returns, all in accordance with Article X hereof. The Trustee shall prepare
      and
      file required state income tax returns and such other returns as may be required
      by applicable law relating to the Trust Fund, and, if required by state law,
      and
      shall file any other documents to the extent required by applicable state tax
      law (to the extent such documents are in the Trustee’s possession). The Trustee
      shall forward copies to the Depositor of all such returns and Form 1099
      supplemental tax information and such other information within the control
      of
      the Trustee as the Depositor may reasonably request in writing, and shall
      distribute to each Certificateholder such forms and furnish such information
      within the control of the Trustee as are required by the Code and the REMIC
      Provisions to be furnished to them, and will prepare and distribute to
      Certificateholders Form 1099 (supplemental tax information) (or otherwise
      furnish information within the control of the Trustee) to the extent required
      by
      applicable law. The Master Servicer shall indemnify the Trustee for any
      liability of or assessment against the Trustee resulting from any error in
      any
      of such tax or information returns directly resulting from errors in the
      information provided by such Master Servicer.

     

    
      
        
        

      

      
        113

        
          

        

      

      
        
        

      

    

     

    (b) The
      Trustee shall prepare and file with the Internal Revenue Service (“IRS”), on
      behalf of the Trust Fund and each of the REMICs specified in the Preliminary
      Statement, an application for an employer identification number on IRS Form
      SS-4
      or by any other acceptable method. The Trustee shall also file a Form 8811
      as
      required. The Trustee, upon receipt from the IRS of the Notice of Taxpayer
      Identification Number Assigned for each REMIC, shall upon request promptly
      forward a copy of such notices to the Master Servicer and the Depositor. The
      Trustee shall have no obligation to verify the information in any Form 8811
      or
      Form SS-4 filing.

     

    (c) The
      Depositor shall prepare or cause to be prepared the initial current report
      on
      Form 8-K. Thereafter, within 10 days (or, if applicable, within such shorter
      period of time as is required under the rules of the Commission) as in effect
      from time to time (the “Rules”)) following each Distribution Date, the Trustee
      shall, in accordance with industry standards and the Rules, prepare and file
      with the Commission via the Electronic Data Gathering and Retrieval System
      (“EDGAR”) the reports listed in subsections (d) through (f) of this Section 6.20
      in respect of the Trust Fund as and to the extent required under the Exchange
      Act each of which reports and any amendment thereof shall be signed by the
      Exchange Act Signing Party.

     

    (d) Reports
      Filed on Form 10-D. 

     

    (i) Within
      15
      days following each Distribution Date (or such later date as may be permissible
      due to an extension of the filing deadline under the Exchange Act), the Trustee
      will prepare and file on a Distribution Report on Form 10-D with respect to
      the
      Trust Fund, which Distribution Report shall include (A) a copy of the
      Distribution Date Statement prepared by the Trustee in respect of the related
      Distribution Date detailing all data elements specified in Item 1121(a) of
      Regulation AB other than those data elements specified in Item 1121(a)(11),
      (12)
      and (14) and (B) the following additional information, data and material
      required to be included in the Distribution Report on Form 10-D for such
      Distribution Date; provided
      that the
      Trustee shall have received from the Depositor, the Sponsor, the Master
      Servicer, the Servicer, any Custodian, the Credit Risk Manager, any Swap
      Counterparty or any Subservicer or Subcontractor therefor no later than three
      Business Days after the related Distribution Date such information, data and
      materials in a form suitable for conversion to the format required for filing
      with the Commission via EDGAR (i.e. not in Adobe/.pdf form):

    


    (1) Item
      1 -
      Distribution and Pool Performance Information (each of the data elements
      specified in Item 1121(a)(11), (12) and (14) of Regulation AB);

     

    
      
        
        

      

      
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    (2) Item
      2 -
      Legal Proceedings (information required by Item 1117 of Regulation
      AB);

     

    (3) Item
      3 -
      Sale of Securities and Use of Proceeds (information required by Item 2 of Part
      II of Form 10-Q);

     

    (4) Item
      4 -
      Defaults Upon Senior Securities (information required by Item 3 of Part II
      of
      Form 10-Q);

     

    (5) Item
      5 -
      Submission of Matters to a Vote of Security Holders (information required by
      Item 4 of Part II of Form 10-Q);

     

    (6) Item
      6 -
      Significant Obligors of Pool Assets (information required by Item 1112(b) of
      Regulation AB);

     

    (7) Item
      7 -
      Significant Enhancement Provider Information (information required by Items
      1114(b)(2) and 1115(b) of Regulation AB);

     

    (8) Item
      8 -
      Other Information (all other information required to be disclosed on Form 8-K
      during the period covered by the report and not yet reported); and 

     

    (9) Item
      9 -
      Exhibits (all exhibits required to be filed by Form 10-D and Item 601 of
      Regulation S-K other than the Distribution Date Statement to be provided by
      the
      Trustee).

     

    (ii) After
      preparing the Form 10-D, the Trustee shall forward electronically a draft copy
      of the Form 10-D to the Exchange
      Act Signing Party for review and approval. If the Master Servicer is the
      Exchange Act Signing Party and the Form 10-D includes Additional Form 10-D
      Disclosure, then the Form 10-D shall also be electronically distributed to
      the
      Depositor for review and approval. No later than two Business Days prior to
      the
      15th
      calendar
      day after the related Distribution Date, a senior officer of the Exchange Act
      Signing Party shall sign the Form 10-D and return an electronic or fax copy
      of
      such signed Form 10-D (with an original executed hard copy to follow by
      overnight mail) to the Trustee.
      If a
      Form 10-D cannot be filed on time or if a previously filed Form 10-D needs
      to be
      amended, the Trustee will follow the procedures set forth in subsection (g)(ii)
      of this Section 6.20. Promptly (but no later than one Business Day) after filing
      with the Commission, the Trustee will make available on its internet website
      a
      final executed copy of each Form 10-D filed by the Trustee. Each party to this
      Agreement acknowledges that the performance by the Trustee of its duties under
      this Section 6.20(d) related to the timely preparation and filing of Form 10-D
      is contingent upon such parties strictly observing all applicable deadlines
      in
      the performance of their duties under this Section 6.20(d). The Trustee shall
      have no liability for any loss, expense, damage, claim arising out of or with
      respect to any failure to properly prepare and/or timely file such Form 10-D,
      where such failure results from the Trustee’s inability or failure to obtain or
      receive, on a timely basis, any information from any other party hereto needed
      to prepare or file such Form 10-D, not resulting from its own negligence, bad
      faith or willful misconduct. The Trustee shall not be responsible (1) for the
      content of any of the information provided pursuant to clauses (d)(i)(1) -
      (9)
      above (unless such item is provided by and specific to the Trustee, in which
      case the Trustee will be responsible for the content of such information;
provided
      that
      such
      information is not revised without the prior consent of the Trustee), (2) for
      determining whether any such information is required to be included in any
      Form
      10-D, (3) for reformatting any information that is not in a form suitable for
      conversion to the format required for filing with the Commission via EDGAR
      (such
      as information that is provided only in Adobe/.pdf form) or (4) for the failure
      to include any information if it is not provided to the Trustee on a timely
      basis (unless such item is specific to the Trustee, in which case the Trustee
      will be responsible for the failure to include such information, unless such
      information is not included in the final Form 10-D without the consent of the
      Trustee).

     

    
      
        
        

      

      
        115

        
          

        

      

      
        
        

      

    

     

    (e) Reports
      Filed on Form 10-K.

     

    (i) On
      or
      prior to March 31 after the end of each fiscal year of the Trust Fund or such
      earlier date as may be required by the Exchange Act (the “10-K Filing Deadline”)
      (it being understood that the fiscal year for the Trust Fund ends on December
      31st
      of each
      year), commencing in March 2007, and, unless and until a Form 15 Suspension
      Notification shall have been filed, the Trustee shall prepare and file (but
      will
      not execute) a Form 10-K in respect of the Trust Fund, which shall include
      the
      certification required pursuant to Rule 13a-14 under the Exchange Act (the
“Form
      10-K Certification”) signed by an appropriate party or parties (which Form 10-K
      Certification the Trustee shall not be required to prepare or sign) and such
      other information as is required by the Rules; provided
      that the
      Trustee shall have received from the Depositor, the Servicer, each Custodian,
      each Additional Servicer, any Servicing Function Participant and the Master
      Servicer (each, a “Reporting Servicer”), no later than March 15 of each calendar
      year prior to the filing deadline for such Annual Report, all information,
      data,
      assessments of compliance, accountant’s attestations and exhibits required to be
      provided or filed with such Annual Report including information, data,
      assessments of compliance, accountant’s attestations and exhibits required to be
      provided in connection with the following Items and other filing requirements
      of
      Form 10-K: 

     

    (A) Item
      9B -
      Other Information (information required to be reported on Form 8-K in the fourth
      quarter but not reported);

     

    (B) Item
      15 -
      Exhibits and Financial Statement Schedules (including all exhibits required
      to
      be filed pursuant to Item 601 of Regulation S-K under the Exchange Act other
      than the certification specified in Item 601(b)(31)(ii) of Regulation S-K and
      the Assessment of Compliance, Attestation Report, and Compliance Statement
      specified in Item 601(b)(33), (34) and (35) of Regulation S-K with respect
      to
      those Servicing Criteria as to which the Trustee is the Item 1122 Responsible
      Party); 

     

    (C) Significant
      Obligor Financial Information (Item 1112(b) of Regulation AB);

     

    (D) Significant
      Enhancement Provider Financial Information (Items 1114(b)(2) and 1115(b) of
      Regulation AB);

     

    
      
        
        

      

      
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    (E) Legal
      Proceedings (Item 1117 of Regulation AB);

     

    (F) Affiliations
      and Certain Relationships and Related; Transactions (Item 1119 of Regulation
      AB);

     

    (G) Compliance
      with applicable Servicing Criteria (Item 1122 of Regulation AB);
      and

     

    (H) Servicer
      Compliance Statement (Item 1123 of Regulation AB).

     

    (ii) After
      preparing the Form 10-K, the Trustee shall forward electronically a draft copy
      of the Form 10-K to the Exchange
      Act Signing Party for review and approval. If the Master
      Servicer is
      the
      Exchange Act Signing Party and the Form 10-K includes Additional Form 10-K
      Disclosure, then the Form 10-K shall also be electronically distributed to
      the
      Depositor for review and approval. No later than the close of business New
      York
      City time on the 4th Business Day prior to the 10-K Filing Deadline, a senior
      officer of the Exchange
      Act Signing Party
      shall
      sign the Form 10-K and return an electronic or fax copy of such signed Form
      10-K
      (with an original executed hard copy to follow by overnight mail) to the
      Trustee. If a Form 10-K cannot be filed on time or if a previously filed Form
      10-K needs to be amended, the Trustee will follow the procedures set forth
      in
      subsection (g) of this Section 6.20. Promptly (but no later than one Business
      Day) after filing with the Commission, the Trustee will make available on its
      internet website a final executed copy of each Form 10-K filed by the Trustee.
      The parties to this Agreement acknowledge that the performance by the Trustee
      of
      its duties under this Section 6.20(e) related to the timely preparation and
      filing of Form 10-K is contingent upon such parties (and any Additional Servicer
      or Servicing Function Participant) strictly observing all applicable deadlines
      in the performance of their duties under this Section
      6.20(e), Section 9.25(a), Section 9.25(b) and Section 9.26.
      The
      Trustee shall have no liability for any loss, expense, damage, claim arising
      out
      of or with respect to any failure to properly prepare and/or timely file such
      Form 10-K, where such failure results from the Trustee’s inability or failure to
      obtain or receive, on a timely basis, any information from any other party
      hereto needed to prepare, arrange for execution or file such Form 10-K, not
      resulting from its own negligence, bad faith or willful misconduct. The Trustee
      shall not be responsible (1) for the content of any of the information provided
      pursuant to clauses (e)(i)(A) - (H) above (unless such item is provided by
      and
      specific to the Trustee, in which case the Trustee will be responsible for
      the
      content of such information; provided
      that
      such
      information is not revised without the prior consent of the Trustee), (2) for
      determining whether any such information is required to be included in any
      Form
      10-K, (3) for reformatting any information that is not in a form suitable for
      conversion to the format required for filing with the Commission via EDGAR
      (such
      as information that is provided only in Adobe/.pdf form) or (4) for the failure
      to include any information if it is not provided to the Trustee on a timely
      basis (unless such item is specific to the Trustee, in which case the Trustee
      will be responsible for the failure to include such information, unless such
      information is not included in the final Form 10-K without the consent of the
      Trustee).

     

    (iii) Unless
      a
      Form 15 Suspension Notification with respect to the Trust Fund has been filed,
      if so requested, on or prior to March 15th
      of each
      year, beginning in March 2007, the Trustee shall sign a certification in the
      form attached hereto as Exhibit M (the “Back-up Certification”) for the benefit
      of the Exchange Act Signing Party and the Person who signs the Form 10-K
      Certification (the “Certifying Party”) regarding certain aspects of such Form
      10-K Certification, upon which the Exchange Act Signing Party and the Certifying
      Party can reasonably rely (provided,
      however,
      that the
      Trustee shall not be required to undertake an analysis of, and shall have no
      responsibility for, any financial information, the accountant’s report,
      certification or other materials contained therein, except for those
      computations prepared by the Trustee and reflected in the distribution report).
      Nothing in this Section 6.20(e)(iii) shall relieve the Trustee of its
      responsibility for the matters as to which it is certifying in the form attached
      hereto as Exhibit M. 

     

    
      
        
        

      

      
        117

        
          

        

      

      
        
        

      

    

     

    (iv) Each
      person (including their officers or directors) that signs any Form 10-K
      Certification shall be entitled to indemnification from the Trust Fund for
      any
      liability or expense incurred by it in connection with such certification,
      other
      than any liability or expense attributable to such Person’s own bad faith,
      negligence or willful misconduct. The provisions of this subsection shall
      survive any termination of this Agreement and the resignation or removal of
      such
      Person

     

    (f) Reports
      Filed on Form 8-K.

     

    (i) Within
      four Business Days after the occurrence of an event requiring disclosure on
      Form
      8-K (each such event, a “Reportable Event”), at the written direction and
      expense of the Depositor, the Trustee shall prepare and file Current Reports
      on
      Form 8-K in respect of the Trust Fund, as required by the Exchange Act;
provided
      that the
      Depositor shall have timely notified the Trustee of an item reportable on a
      Current Report on Form 8-K and shall have delivered to the Trustee no later
      than
      two Business Days prior to the filing deadline for such Current Report, all
      information, data, and exhibits required to be provided or filed with such
      Current Report (“Form 8-K Disclosure Information”), including, particularly,
      information, data and exhibits, in a form suitable for conversion to the format
      required for filing with the Commission via EDGAR (i.e. not in Adobe/.pdf form),
      required to be provided in connection with the following Items of Form 8-K:
      

     

    (A) Item
      1.01
      - Entry into a Material Definitive Agreement;

     

    (B) Item
      1.02
      - Termination of a Material Definitive Agreement;

     

    (C) Item
      1.03
      - Bankruptcy or Receivership;

     

    (D) Item
      2.04
      - Triggering Events that Accelerate or Increase a Direct Financial Obligation
      or
      an Obligation under an Off-Balance Sheet Arrangement;

     

    (E) Item
      3.03
      - Material Modification to Rights of Security Holders;

     

    (F) Item
      5.03
      - Amendments of Articles of Incorporation or Bylaws; Change of Fiscal
      Year

     

    
      
        
        

      

      
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    (G) Item
      6.02
      - Change in Servicer or Trustee;

     

    (H) Item
      6.03
      - Change in Credit Enhancement or Other External Support;

     

    (I) Item
      6.04
      - Failure to Make a Required Distribution; and

     

    (J) Item
      6.05
      - Securities Act Updating Disclosure.

     

    (ii) After
      preparing the Form 8-K, the Trustee shall forward electronically, no later
      than
      Noon New York City time on the 3rd Business Day after the Reportable Event,
      a
      draft copy of the Form 8-K to the Exchange Act Signing Party for review and
      approval. If the Master Servicer is the Exchange Act Signing Party, then the
      Form 8-K shall also be electronically distributed to the Depositor for review
      and approval. No later than 1:00 p.m. New York City time on the 4th Business
      Day
      after the Reportable Event, a senior officer of the Exchange Act Signing Party
      shall sign the Form 8-K and return an electronic or fax copy of such signed
      Form
      8-K (with an original executed hard copy to follow by overnight mail) to the
      Trustee. If a Form 8-K cannot be filed on time or if a previously filed Form
      8-K
      needs to be amended, the Trustee will follow the procedures set forth in
      subsection (g) of this Section 6.20. Promptly (but no later than one Business
      Day) after filing with the Commission, the Trustee will, make available on
      its
      internet website a final executed copy of each Form 8-K. The parties to this
      Agreement acknowledge that the performance by the Trustee of its duties under
      this Section 6.20(f) related to the timely preparation and filing of Form 8-K
      is
      contingent upon such parties strictly observing all applicable deadlines in
      the
      performance of their duties under this Section 6.20(f). The Trustee shall have
      no liability for any loss, expense, damage, claim arising out of or with respect
      to any failure to properly prepare and/or timely file such Form 8-K, where
      such
      failure results from the Trustee’s inability or failure to obtain or receive, on
      a timely basis, any information from any other party hereto needed to prepare
      or
      file such Form 8-K, not resulting from its own negligence, bad faith or willful
      misconduct. The Trustee shall not be responsible (1) for the content of any
      of
      the information provided pursuant to clauses (f)(i)(A) - (J) above (unless
      such
      item is provided by and specific to the Trustee, in which case the Trustee
      will
      be responsible for the content of such information; provided
      that
      such information is not revised without the prior consent of the Trustee),
      (2)
      for determining what information is required to be filed on a Form 8-K in
      connection with the transactions contemplated by this Agreement (unless such
      information is specific to the Trustee, in which case the Trustee will be
      responsible for making such a determination, unless such information is not
      included in the final Form 8-K without the consent of the Trustee), (3) for
      reformatting any information that is not in a form suitable for conversion
      to
      the format required for filing with the Commission via EDGAR (such as
      information that is provided only in Adobe/.pdf form) or (4) for any late filing
      of a Form 8-K in the event that it does not receive all information, data,
      signatures and exhibits required to be provided or filed on or prior to the
      second Business Day prior to the applicable filing deadline.

     

    (g) Delisting;
      Amendments; Late Filings.

     

    
      
        
        

      

      
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    (i) Prior
      to
      January 30 of the first year in which the Trustee is able to do so under
      applicable law, unless otherwise directed by the Depositor in writing, the
      Trustee shall prepare and file a Form 15 relating to the automatic suspension
      of
      reporting in respect of the Trust Fund under the Exchange Act. 

     

    (ii) In
      the
      event that the Trustee becomes aware that it will be unable to timely file
      with
      the Commission all or any required portion of any Form 8-K, 10-D or 10-K
      required to be filed by this Agreement because required disclosure information
      was either not delivered to it or delivered to it after the delivery deadlines
      set forth in this Agreement or for any other reason, the Trustee will
      immediately notify the Depositor. In the case of Form 10-D and 10-K, the parties
      to this Agreement and the Servicer will cooperate to prepare and file a Form
      12b-25 and a 10-D/A and 10-K/A as applicable, pursuant to Rule 12b-25 of the
      Exchange Act. In the case of Form 8-K, the Trustee will, upon receipt of all
      required Form 8-K Disclosure Information and upon the approval and direction
      of
      the Depositor, include such disclosure information on the next Form 10-D. In
      the
      event that any previously filed Form 8-K, 10-D or 10-K needs to be amended,
      the
      Trustee will notify the Depositor and the Master Servicer and such parties
      will
      cooperate to prepare any necessary 8-K/A, 10-D/A or 10-K/A. Any Form 15, Form
      12b-25 or any amendment to Form 8-K, 10-D or 10-K shall be signed by a senior
      officer of the Exchange Act Signing Party. The parties to this Agreement
      acknowledge that the performance by the Trustee of its duties under this Section
      6.20(g) related to the timely preparation and filing of Form 15, a Form 12b-25
      or any amendment to Form 8-K, 10-D or 10-K is contingent upon each such party
      performing its duties under this Section. The Trustee shall have no liability
      for any loss, expense, damage, claim arising out of or with respect to any
      failure to properly prepare and/or timely file any such Form 15, Form 12b-25
      or
      any amendments to Forms 8-K, 10-D or 10-K, where such failure results from
      the
      Trustee’s inability or failure to obtain or receive, on a timely basis, any
      information from any other party hereto needed to prepare, arrange for execution
      or file such Form 15, Form 12b-25 or any amendments to Forms 8-K, 10-D or 10-K,
      not resulting from its own negligence, bad faith or willful
      misconduct.

     

    (h) The
      Trustee, with the prior consent of the Depositor, may include in any Exchange
      Act report all relevant information, data, and exhibits as the Trustee may
      receive in connection with such report irrespective of any provision that may
      permit the exclusion of such material. For example, the Trustee, with the prior
      consent of the Depositor, may file all Assessments of Compliance, Attestation
      Reports and Compliance Statements timely received from any Item 1122 Responsible
      Party irrespective of any applicable minimum pool asset percentage requirement
      for disclosure related to such Item 1122 Responsible Party.

     

    (i) Any
      party
      that signs any Exchange Act report that the Trustee is required to file shall
      provide to the Trustee prompt notice of the execution of such Exchange Act
      report along with the name and contact information for the person signing such
      report and shall promptly deliver to the Trustee the original executed signature
      page for such report. In addition, each of the parties agrees to provide to
      the
      Trustee such additional information related to such party as the Trustee may
      reasonably request, including evidence of the authorization of the person
      signing any certification or statement, financial information and reports,
      and
      such other information related to such party or its performance hereunder.
      

     

    
      
        
        

      

      
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    (j) The
      Depositor and the Master Servicer, by mutual agreement, shall determine which
      of
      the Depositor or the Master Servicer shall be the initial Exchange Act Signing
      Party. Upon such determination, the Depositor shall timely notify the Trustee,
      and such notice shall provide contact information for the Exchange Act Signing
      Party. If the Depositor and Master Servicer, at any time, mutually agree to
      change the identity of the Exchange Act Signing Party, the Depositor shall
      provide timely notice to the Trustee of any such change.

     

    
      	 	
              Section
                6.21 

            	
              Compliance
                with Regulation AB.

            


    

     

    Each
      of
      the parties hereto acknowledges and agrees that the purpose of Sections 6.01
      and
      6.20 of this Agreement is to facilitate compliance by the Sponsor, the Master
      Servicer, the Depositor and the Trustee with the provisions of Regulation AB,
      as
      such may be amended or clarified from time to time. Therefore, each of the
      parties agrees that (a) the obligations of the parties hereunder shall be
      interpreted in such a manner as to accomplish compliance with Regulation AB,
      (b)
      the parties’
      obligations hereunder will be supplemented and modified as necessary to be
      consistent with any such amendments, interpretive advice or guidance from the
      Commission, convention or consensus among active participants in the
      asset-backed securities markets, or otherwise in respect of the requirements
      of
      Regulation AB and (c) the parties shall comply with reasonable requests made
      by
      the Sponsor, the Master Servicer, the Depositor or the Trustee for delivery
      of
      additional or different information, to the extent such information is available
      or reasonably attainable, as the Sponsor, the Master Servicer, the Depositor
      or
      the Trustee may determine in good faith is necessary to comply with the
      provisions of Regulation AB.

     

    ARTICLE
      VII

     

    PURCHASE
      OF MORTGAGE LOANS AND

    TERMINATION
      OF THE TRUST FUND

     

    
      	 	
              Section
                7.01 

            	
              Purchase
                of Mortgage Loans; Termination of Trust Fund Upon Purchase or Liquidation
                of All Mortgage Loans; Purchase of Lower Tier REMIC 1 Uncertificated
                Regular Interests.  

            


    

     

    (a) The
      respective obligations and responsibilities of the Trustee and the Master
      Servicer created hereby (other than the obligation of the Trustee to make
      payments to Certificateholders and the Swap Counterparty as set forth in Section
      7.02, the obligation of the Master Servicer to make a final remittance to the
      Trustee pursuant to Section 4.01, and the obligations of the Master Servicer
      to
      the Trustee pursuant to Sections 9.10, 9.14 and 9.31) shall terminate on the
      earliest of (i) the final payment or other liquidation of the last Mortgage
      Loan
      remaining in the Trust Fund and the disposition of all REO Property, (ii) the
      sale of the property held by the Trust Fund in accordance with Section 7.01(b)
      and (iii) the Latest Possible Maturity Date; (each, a “Trust Fund Termination
      Event”); provided,
      however,
      that in
      no event shall the Trust Fund created hereby continue beyond the expiration
      of
      21 years from the death of the last survivor of the descendants of Joseph P.
      Kennedy, the late Ambassador of the United States to the Court of St. James’s,
      living on the date hereof. Upon the occurrence of a Trust Fund Termination
      Event, each REMIC shall be terminated in a manner that shall qualify as a
“qualified liquidation” under the REMIC Provisions as evidenced by an Opinion of
      Counsel provided to the Trustee at the expense of the Trust Fund.

     

    
      
        
        

      

      
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    (b) On
      any
      Distribution Date occurring on or after the Initial Optional Termination Date,
      the Master Servicer or LTURI-holder, as applicable, with the prior written
      consent of the Seller, which consent shall not be unreasonably withheld, has
      the
      option to cause the Trust Fund to adopt a plan of complete liquidation pursuant
      to Section 7.03(a)(i) hereof to sell all of its property. Upon exercise of
      such
      option, the property of the Trust Fund shall be sold to the Master Servicer
      at a
      price (the “Termination Price”) equal to the sum of (i) 100% of the unpaid
      principal balance of each Mortgage Loan on the day of such purchase plus
      interest accrued thereon at the applicable Mortgage Rate with respect to any
      Mortgage Loan to the Due Date in the Collection Period immediately preceding
      the
      related Distribution Date to the date of such repurchase, (ii) the fair market
      value of any REO Property and any other property held by any REMIC, such fair
      market value to be determined by an independent appraiser or appraisers mutually
      agreed upon by the Master Servicer (reduced, in the case of REO Property, by
      (1)
      reasonably anticipated disposition costs and (2) any amount by which the fair
      market value as so reduced exceeds the outstanding principal balance of the
      related Mortgage Loan plus interest accrued thereon at the applicable Net
      Mortgage Rate to the date of such purchase), (iii) any unreimbursed Servicing
      Advances and (iv) any Swap Termination Payment payable to the Swap Counterparty
      as a result of a termination pursuant to this Section 7.01. The Master Servicer,
      the Servicer, the Trustee and the related Custodian shall be reimbursed from
      the
      Termination Price for any Mortgage Loan or related REO Property for any Advances
      made or other amounts advanced with respect to the Mortgage Loans that are
      reimbursable to any such entity under this Agreement, the Servicing Agreement
      or
      the related Custodial Agreement, together with any accrued and unpaid
      compensation and any other amounts due to the Master Servicer or the Trustee
      hereunder or the Servicer or the Custodians. 

     

    (c) On
      any
      Distribution Date occurring on or after the Initial Optional Termination Date,
      the Master Servicer, with the prior written consent of the Seller, which consent
      shall not be unreasonably withheld, has the option to purchase all of the Lower
      Tier REMIC 1 Uncertificated Regular Interests. Upon exercise of such option,
      the
      Lower Tier REMIC 1 Uncertificated Regular Interests shall be sold to the Master
      Servicer at a price (the “Lower Tier REMIC 1 Uncertificated Regular Interests
      Purchase Price”) equal to the sum of (i) 100% of the unpaid principal balance of
      each Mortgage Loan on the day of such purchase plus interest accrued thereon
      at
      the applicable Mortgage Rate with respect to any Mortgage Loan to the Due Date
      in the Collection Period immediately preceding the related Distribution Date
      to
      the date of such repurchase and (ii) the fair market value of any REO Property
      and any other property held by any REMIC, such fair market value to be
      determined by an independent appraiser or appraisers mutually agreed upon by
      the
      Master Servicer and the Trustee (reduced, in the case of REO Property, by (1)
      reasonably anticipated disposition costs and (2) any amount by which the fair
      market value as so reduced exceeds the outstanding principal balance of the
      related Mortgage Loan plus interest accrued thereon at the applicable Net
      Mortgage Rate to the date of such purchase). If the Master Servicer elects
      to
      exercise such option, each REMIC created pursuant to this Agreement (other
      than
      REMIC 1) shall be terminated in such a manner so that the termination of each
      such REMIC shall qualify as a “qualified liquidation” under the REMIC Provisions
      and the Lower Tier REMIC 1 Uncertificated Regular Interests and the Class LT-R
      Certificates will evidence the entire beneficial interest in the property of
      the
      Trust Fund. Following a purchase of the Lower Tier REMIC 1 Uncertificated
      Regular Interests pursuant to this subsection, the Trust Fund (and REMIC 1)
      will
      remain outstanding and final payment on the Certificates (other than the Class
      LT-R Certificates) will be made in accordance with Sections 7.03(a)(iii) and
      5.02. The Trust Fund will terminate upon the occurrence of a Trust Fund
      Termination Event, in accordance with Section 7.01(a).

     

    
      
        
        

      

      
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              Section
                7.02 

            	
              Procedure
                Upon Termination of Trust Fund or Purchase of Lower Tier REMIC 1
                Uncertificated Regular Interests.  

            


    

     

    (a) Notice
      of
      any Trust Fund Termination Event and notice of the purchase of the Lower Tier
      REMIC 1 Uncertificated Regular Interests, specifying the Distribution Date
      upon
      which the final distribution to the Certificates (other than the Class LT-R
      Certificates, in the case of a purchase of the Lower Tier REMIC 1 Uncertificated
      Regular Interests) shall be made, shall be given by the Trustee by first class
      mail to Certificateholders and (if the Swap Agreement is still in force) the
      Swap Counterparty mailed promptly (and in no event later than five Business
      Days) (x) after the Trustee has received notice from the Master Servicer or
      the
      LTURI-holder, as applicable, of its election to cause (1) the sale of all of
      the
      property of the Trust Fund pursuant to Section 7.01(b) or (2) the purchase
      of
      the Lower Tier REMIC 1 Uncertificated Regular Interests pursuant to Section
      7.01(c), or (y) upon the final payment or other liquidation of the last Mortgage
      Loan or REO Property in the Trust Fund. In the case of a Trust Fund Termination
      Event, the Trustee shall also give notice to the Master Servicer, the Swap
      Counterparty and the Certificate Registrar at the time notice is given to
      Holders.

     

    In
      the
      case of a Trust Fund Termination Event, such notice shall specify (A) the
      Distribution
      Date
      upon which final distribution on the Certificates or Lower Tier REMIC 1
      Uncertificated Regular Interests of all amounts required to be distributed
      to
      Certificateholders pursuant to Section 5.02 will be made upon presentation
      and
      surrender of the Certificates at the Corporate Trust Office, and (B) that the
      Record Date otherwise applicable to such Distribution Date is not applicable,
      distribution being made only upon presentation and surrender of the Certificates
      at the office or agency of the Trustee therein specified. Upon any such Trust
      Fund Termination Event, the duties of the Certificate Registrar with respect
      to
      the Certificates or Lower Tier REMIC 1 Uncertificated Regular Interests shall
      terminate and the Trustee shall terminate or request the Master Servicer to
      terminate, the Collection Account it maintains, the Certificate Account and
      any
      other account or fund maintained with respect to the Certificates or Lower
      Tier
      REMIC 1 Uncertificated Regular Interests, subject to the Trustee’s obligation
      hereunder to hold all amounts payable to Certificateholders in trust without
      interest pending such payment. 

     

    In
      the
      case of a purchase of the Lower Tier REMIC 1 Uncertificated Regular Interests,
      such notice shall specify (A) the Distribution Date upon which final
      distribution on the Certificates (other than the Class LT-R Certificates) of
      all
      amounts required to be distributed to Certificateholders pursuant to Section
      5.02 (other than any distributions to the Class LT-R Certificates in respect
      of
      REMIC 1) will be made upon presentation and surrender of the Certificates (other
      than the Class LT-R Certificates) at the Corporate Trust Office, and (B) that
      the Record Date
      otherwise applicable to such Distribution Date is not applicable, distribution
      being made only upon presentation and surrender of the Certificates (other
      than
      the Class LT-R Certificates) at the office or agency of the Trustee therein
      specified. Upon any such purchase of the Lower Tier REMIC 1 Uncertificated
      Regular Interests, the duties of the Certificate Registrar with respect to
      the
      Certificates other than the Class LT-R Certificate shall terminate but the
      Trustee shall not terminate or request the Master Servicer to terminate, the
      Collection Account it maintains, the Certificate Account and any other account
      or fund maintained with respect to the Certificates, subject to the Trustee’s
      obligation hereunder to hold all amounts payable to Certificateholders in trust
      without interest pending such payment. For all Distribution Dates following
      the
      Distribution Date on which the Master Servicer purchases the Lower Tier REMIC
      1
      Uncertificated Regular Interests, all amounts that would be distributed on
      the
      Certificates (other than the Class LT-R Certificate and exclusive of amounts
      payable from any fund held outside of REMIC 1) absent such purchase shall be
      payable to the LTURI-holder.

     

    
      
        
        

      

      
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    (b) In
      the
      event that all of the Holders do not surrender their Certificates for
      cancellation within three months after the time specified in the above-mentioned
      written notice, the Trustee shall give a second written notice to the remaining
      Certificateholders to surrender their Certificates for cancellation and receive
      the final distribution with respect thereto. If within one year after the second
      notice any Certificates shall not have been surrendered for cancellation, the
      Trustee may take appropriate steps to contact the remaining Certificateholders
      concerning surrender of such Certificates, and the cost thereof shall be paid
      out of the amounts distributable to such Holders. If within two years after
      the
      second notice any Certificates shall not have been surrendered for cancellation,
      the Trustee shall, subject to applicable state law relating to escheatment,
      hold
      all amounts distributable to such Holders for the benefit of such Holders.
      No
      interest shall accrue on any amount held by the Trustee and not distributed
      to a
      Certificateholder due to such Certificateholder’s failure to surrender its
      Certificate(s) for payment of the final distribution thereon in accordance
      with
      this Section.

     

    (c) Any
      reasonable expenses incurred by the Trustee in connection with any Trust Fund
      Termination Event or any purchase of the Lower Tier REMIC 1 Uncertificated
      Regular Interests shall be reimbursed from proceeds received from such
      termination or purchase.

     

    
      	 	
              Section
                7.03 

            	
              Additional
                Trust Fund Termination Event or Purchase of the Lower Tier REMIC 1
                Uncertificated Regular Interests.  

            


    

     

    (a) Any
      termination of the Trust Fund pursuant to Section 7.01(a) or any
      termination of a REMIC pursuant to Section 7.01(c) shall be effected in
      accordance with the following additional requirements, unless the Trustee seeks
      (at the request of the party exercising the option to purchase all of the
      Mortgage Loans or Lower Tier REMIC 1 Uncertificated Regular Interests
      pursuant to Section 7.01(b) or Section 7.01(c), respectively), and
      subsequently receives, an Opinion of Counsel (at the expense of such requesting
      party), addressed to the Trustee to the effect that the failure to comply with
      the requirements of this Section 7.03 will not result in an Adverse REMIC
      Event:

     

    (i) Within
      89
      days prior to the time of the making of the final payment on the Certificates
      (other than the Class LT-R Certificates, in the case of a purchase of the
      Lower Tier REMIC 1 Uncertificated Regular Interests, upon notification by
      the Master Servicer or an Affiliate of the Seller that it intends to exercise
      its option to cause the termination or purchase the Lower Tier REMIC 1
      Uncertificated Regular Interests, the Trustee shall adopt a plan of complete
      liquidation of the Trust Fund on behalf of each REMIC (other than REMIC 1,
      in the case of a purchase of the Lower Tier REMIC 1 Uncertificated Regular
      Interests), meeting the requirements of a qualified liquidation under the REMIC
      Provisions;

     

    
      
        
        

      

      
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    (ii) Any
      sale
      of the assets of the Trust Fund or the Lower Tier REMIC 1 Uncertificated
      Regular Interests pursuant to Section 7.02 shall be a sale for cash and shall
      occur at or after the time of adoption of such a plan of complete liquidation
      and prior to the time of making of the final payment on the Certificates (other
      than the Class LT-R Certificates, in the case of a purchase of the Lower
      Tier REMIC 1 Uncertificated Regular Interests);

     

    (iii) On
      the
      date specified for final payment of the Certificates (other than the Class
      LT-R
      Certificates, in the case of a purchase of the Lower
      Tier REMIC 1 Uncertificated Regular Interests),
      the
      Trustee shall make final distributions of principal and interest on such
      Certificates and shall pay, in the case of a Trust Fund Termination Event,
      any
      Swap Termination Payment owed to the Swap Counterparty on the related Swap
      Payment Date (to the extent not paid on previous Swap Payment Dates) in
      accordance with Section 5.02. In the case of a Trust Fund Termination Event,
      and, after payment of, or provision for any outstanding expenses, the Trustee
      shall distribute or credit, or cause to be distributed or credited, to the
      Holders of the Residual Certificates all cash on hand after such final payment
      (other than cash retained to meet claims), and the Trust Fund (and each REMIC)
      shall terminate at that time; and

     

    (iv) In
      no
      event may the final payment on the Certificates or the final distribution or
      credit to the Holders of the Residual Certificates in respect of the residual
      interest in any liquidated REMIC be made after the 89th day from the date on
      which the plan of complete liquidation for such REMIC is adopted.

     

    (b) By
      its
      acceptance of a Residual Certificate, each Holder thereof hereby agrees to
      accept the plan of complete liquidation prepared by the Depositor and adopted
      by
      the Trustee under this Section and to take such other action in connection
      therewith as may be reasonably requested by the Master Servicer or the
      Servicer.

     

    (c) In
      connection with the termination of the Trust Fund or a Section 7.01(c) Purchase
      Event, the Trustee may request an Opinion of Counsel addressed to the Trustee
      (at the expense of the Depositor) to the effect that all the requirements of
      a
      qualified liquidation under the REMIC Provisions have been met.

     

    
      	 	
              Section
                7.04 

            	
              Charged-off
                Loans and Released Mortgage
                Loans.

            


    

     

    Notwithstanding
      anything to the contrary contained in this Agreement, each Charged-off Loan
      that
      becomes a Released Mortgage Loan shall be released from the Trust Fund as soon
      as practicable after becoming a Released Mortgage Loan and shall no longer
      be an
      asset of any REMIC. Each Released Mortgage Loan shall be transferred to the
      Released Mortgage Transferee, without recourse. Thereafter (i) the Released
      Mortgage Transferee shall be entitled to any amounts subsequently received
      in
      respect of any such Released Mortgage Loans, (ii) the Released Mortgage
      Transferee may designate any servicer to service any such Released Mortgage
      Loan
      and (iii) the Released Mortgage Transferee may sell any such Released Mortgage
      Loan to a third party. For purposes of compliance with the REMIC Provisions,
      any
      such Released Mortgage Loan transferred to the Released Mortgage Transferee
      pursuant to this Section 7.04 and having any value as of the date of such
      transfer shall be treated as having been transferred by the related REMIC as
      additional compensation for services provided to such REMIC.

     

    
      
        
        

      

      
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    ARTICLE
      VIII

     

    RIGHTS
      OF
      CERTIFICATEHOLDERS

     

    
      	 	
              Section
                8.01 

            	
              Limitation
                on Rights of Holders.  

            


    

     

    (a) The
      death
      or incapacity of any Certificateholder shall not operate to terminate this
      Agreement or this Trust Fund, nor entitle such Certificateholder’s legal
      representatives or heirs to claim an accounting or take any action or proceeding
      in any court for a partition or winding up of this Trust Fund, nor otherwise
      affect the rights, obligations and liabilities of the parties hereto or any
      of
      them. Except as otherwise expressly provided herein, no Certificateholder,
      solely by virtue of its status as a Certificateholder, shall have any right
      to
      vote or in any manner otherwise control the Master Servicer or the operation
      and
      management of the Trust Fund, or the obligations of the parties hereto, nor
      shall anything herein set forth, or contained in the terms of the Certificates,
      be construed so as to constitute the Certificateholders from time to time as
      partners or members of an association, nor shall any Certificateholder be under
      any liability to any third person by reason of any action taken by the parties
      to this Agreement pursuant to any provision hereof.

     

    (b) No
      Certificateholder, solely by virtue of its status as Certificateholder, shall
      have any right by virtue or by availing of any provision of this Agreement
      to
      institute any suit, action or proceeding in equity or at law upon or under
      or
      with respect to this Agreement, unless such Holder previously shall have given
      to the Trustee a written notice of an Event of Default and of the continuance
      thereof, as hereinbefore provided, and unless also the Holders of Certificates
      evidencing not less than 25% of the Class Principal Amount (or Percentage
      Interest) of Certificates of each Class affected thereby shall have made written
      request upon the Trustee to institute such action, suit or proceeding in its
      own
      name as Trustee hereunder and shall have offered to the Trustee such reasonable
      indemnity as it may require against the cost, expenses and liabilities to be
      incurred therein or thereby, and the Trustee, for sixty days after its receipt
      of such notice, request and offer of indemnity, shall have neglected or refused
      to institute any such action, suit or proceeding and no direction inconsistent
      with such written request has been given the Trustee during such sixty-day
      period by such Certificateholders; it being understood and intended, and being
      expressly covenanted by each Certificateholder with every other
      Certificateholder and the Trustee, that no one or more Holders of Certificates
      shall have any right in any manner whatever by virtue or by availing of any
      provision of this Agreement to affect, disturb or prejudice the rights of the
      Holders of any other of such Certificates, or to obtain or seek to obtain
      priority over or preference to any other such Holder, or to enforce any right
      under this Agreement, except in the manner herein provided and for the benefit
      of all Certificateholders. For the protection and enforcement of the provisions
      of this Section, each and every Certificateholder and the Trustee shall be
      entitled to such relief as can be given either at law or in equity.

     

    
      
        
        

      

      
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              Section
                8.02 

            	
              Access
                to List of Holders.  

            


    

     

    (a) If
      the
      Trustee is not acting as Certificate Registrar, the Certificate Registrar will
      furnish or cause to be furnished to the Trustee, within fifteen days after
      receipt by the Certificate Registrar of a request by the Trustee in writing,
      a
      list, in such form as the Trustee may reasonably require, of the names and
      addresses of the Certificateholders of each Class as of the most recent Record
      Date.

     

    (b) If
      three
      or more Holders or Certificate Owners (hereinafter referred to as “Applicants”)
      apply in writing to the Trustee, and such application states that the Applicants
      desire to communicate with other Holders with respect to their rights under
      this
      Agreement or under the Certificates and is accompanied by a copy of the
      communication which such Applicants propose to transmit, then the Trustee shall,
      within five Business Days after the receipt of such application, afford such
      Applicants reasonable access during the normal business hours of the Trustee
      to
      the most recent list of Certificateholders held by the Trustee or shall, as
      an
      alternative, send, at the Applicants’ expense, the written communication
      proffered by the Applicants to all Certificateholders at their addresses as
      they
      appear in the Certificate Register.

     

    (c) Every
      Holder or Certificate Owner, if the Holder is a Clearing Agency, by receiving
      and holding a Certificate, agrees with the Depositor, the Master Servicer,
      the
      Certificate Registrar and the Trustee that none of the Depositor, the Master
      Servicer, the Certificate Registrar, the Paying Agent or the Trustee shall
      be
      held accountable by reason of the disclosure of any such information as to
      the
      names and addresses of the Certificateholders hereunder, regardless of the
      source from which such information was derived.

     

    
      	 	
              Section
                8.03 

            	
              Acts
                of Holders of Certificates.  

            


    

     

    (a) Any
      request, demand, authorization, direction, notice, consent, waiver or other
      action provided by this Agreement to be given or taken by Holders or Certificate
      Owner, if the Holder is a Clearing Agency, may be embodied in and evidenced
      by
      one or more instruments of substantially similar tenor signed by such Holders
      in
      person or by agent duly appointed in writing; and, except as herein otherwise
      expressly provided, such action shall become effective when such instrument
      or
      instruments are delivered to the Trustee, the Certificate Registrar and the
      Paying Agent and, where expressly required herein, to the Master Servicer.
      Such
      instrument or instruments (as the action embodies therein and evidenced thereby)
      are herein sometimes referred to as an “act” of the Holders signing such
      instrument or instruments. Proof of execution of any such instrument or of
      a
      writing appointing any such agents shall be sufficient for any purpose of this
      Agreement and conclusive in favor of the Trustee and the Master Servicer, if
      made in the manner provided in this Section. Each of the Trustee and the Master
      Servicer shall promptly notify the others of receipt of any such instrument
      by
      it, and shall promptly forward a copy of such instrument to the
      others.

     

    (b) The
      fact
      and date of the execution by any Person of any such instrument or writing may
      be
      proved by the affidavit of a witness of such execution or by the certificate
      of
      any notary public or other officer authorized by law to take acknowledgments
      or
      deeds, certifying that the individual signing such instrument or writing
      acknowledged to him the execution thereof. Whenever such execution is by an
      officer of a corporation or a member of a partnership on behalf of such
      corporation or partnership, such certificate or affidavit shall also constitute
      sufficient proof of his authority. The fact and date of the execution of any
      such instrument or writing, or the authority of the individual executing the
      same, may also be proved in any other manner which the Trustee deems
      sufficient.

     

    
      
        
        

      

      
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    (c) The
      ownership of Certificates or Lower Tier REMIC 1 Uncertificated Regular Interests
      (whether or not such Certificates or Lower Tier REMIC 1 Uncertificated Regular
      Interests shall be overdue and notwithstanding any notation of ownership or
      other writing thereon made by anyone other than the Trustee) shall be proved
      by
      the Certificate Register, and none of the Trustee, the Master Servicer, the
      Paying Agent or the Depositor shall be affected by any notice to the
      contrary.

     

    (d) Any
      request, demand, authorization, direction, notice, consent, waiver or other
      action by the Holder of any Certificate or Lower Tier REMIC 1 Uncertificated
      Regular Interest shall bind every future Holder of the same Certificate or
      Lower
      Tier REMIC 1 Uncertificated Regular Interest and the Holder of every Certificate
      or Lower Tier REMIC 1 Uncertificated Regular Interest issued upon the
      registration of transfer thereof or in exchange therefor or in lieu thereof,
      in
      respect of anything done, omitted or suffered to be done by the Trustee or
      the
      Master Servicer in reliance thereon, whether or not notation of such action
      is
      made upon such Certificate or Lower Tier REMIC 1 Uncertificated Regular
      Interest.

     

    ARTICLE
      IX

     

    ADMINISTRATION
      AND SERVICING OF MORTGAGE LOANS

    BY
      THE
      MASTER SERVICER; CREDIT RISK MANAGER

     

    
      	 	
              Section
                9.01 

            	
              Duties
                of the Master Servicer. 

            


    

     

    The
      Certificateholders, by their purchase and acceptance of the Certificates or
      Lower Tier REMIC 1 Uncertificated Regular Interests, appoint Aurora Loan
      Services LLC, as Master Servicer. For and on behalf of the Depositor, the
      Trustee and the Certificateholders, the Master Servicer shall master service
      the
      Mortgage Loans in accordance with the provisions of this Agreement and the
      provisions of the Servicing Agreement. Notwithstanding anything in this
      Agreement, the Servicing Agreement or the Credit Risk Management Agreement
      to
      the contrary, the Master Servicer shall have no duty or obligation to enforce
      the Credit Risk Management Agreement or to supervise, monitor or oversee the
      activities of the Servicer under its Credit Risk Management Agreement with
      respect to any action taken or not taken by the Servicer at the direction of
      the
      Seller or pursuant to a recommendation of the Credit Risk Manager.

     

    
      	 	
              Section
                9.02 

            	
              Master
                Servicer Fidelity Bond and Master Servicer Errors and Omissions Insurance
                Policy. 

            


    

     

    (a) The
      Master Servicer, at its expense, shall maintain in effect a Master Servicer
      Fidelity Bond and a Master Servicer Errors and Omissions Insurance Policy,
      affording coverage with respect to all directors, officers, employees and other
      Persons acting on such Master Servicer’s behalf, and covering errors and
      omissions in the performance of the Master Servicer’s obligations hereunder. The
      Master Servicer Errors and Omissions Insurance Policy and the Master Servicer
      Fidelity Bond shall be in such form and amount that would be consistent with
      coverage customarily maintained by master servicers of mortgage loans similar
      to
      the Mortgage Loans and the Master Servicer shall provide the Trustee upon
      request, with a copy of such policy and fidelity bond. The Master Servicer
      shall
      (i) require the Servicer to maintain an Errors and Omissions Insurance Policy
      and a Servicer Fidelity Bond in accordance with the provisions of the Servicing
      Agreement, (ii) cause the Servicer to provide to the Master Servicer
      certificates evidencing that such policy and bond is in effect and to furnish
      to
      the Master Servicer any notice of cancellation, non-renewal or modification
      of
      the policy or bond received by it, as and to the extent provided in the
      Servicing Agreement, and (iii) furnish copies of such policies and of the
      certificates and notices referred to in clause (ii) to the Trustee upon
      request.

     

    
      
        
        

      

      
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    (b) The
      Master Servicer shall promptly report to the Trustee any material changes that
      may occur in the Master Servicer Fidelity Bond or the Master Servicer Errors
      and
      Omissions Insurance Policy and shall furnish to the Trustee, on request,
      certificates evidencing that such bond and insurance policy are in full force
      and effect. The Master Servicer shall promptly report to the Trustee all cases
      of embezzlement or fraud, if such events involve funds relating to the Mortgage
      Loans. The total losses, regardless of whether claims are filed with the
      applicable insurer or surety, shall be disclosed in such reports together with
      the amount of such losses covered by insurance. If a bond or insurance claim
      report is filed with any of such bonding companies or insurers, the Master
      Servicer shall promptly furnish a copy of such report to the Trustee. Any
      amounts relating to the Mortgage Loans collected by the Master Servicer under
      any such bond or policy shall be promptly remitted by the Master Servicer to
      the
      Trustee for deposit into the Certificate Account. Any amounts relating to the
      Mortgage Loans collected by the Servicer under any such bond or policy shall
      be
      remitted to the Master Servicer to the extent provided in the Servicing
      Agreement.

     

    
      	 	
              Section
                9.03 

            	
              Master
                Servicer’s Financial Statements and Related Information. 

            


    

     

    For
      each
      year this Agreement is in effect, the Master Servicer shall submit to the
      Trustee, each Rating Agency and the Depositor
      a copy of the annual audited financial statements of its corporate parent on
      or
      prior to March 31 of each year, commencing on March 31, 2007. Such financial
      statements shall include comparative balance sheets, income statements,
      statement of changes in shareholder’s equity, statements of cash flows, a
      consolidating schedule showing consolidated subsidiaries and any related notes
      required pursuant to generally accepted accounting principles, certified by
      a
      nationally recognized firm of Independent Accountants to the effect that such
      financial statements were examined and prepared in accordance with generally
      accepted accounting principles applied on a basis consistent with that of the
      preceding year.

     

    
      	 	
              Section
                9.04 

            	
              Power
                to Act; Procedures. 

            


    

     

    (a) The
      Master Servicer shall master service the Mortgage Loans and shall have full
      power and authority, subject to the REMIC Provisions and the provisions of
      Article X hereof, and the Servicer shall have full power and authority (to
      the
      extent provided in the Servicing Agreement) to do any and all things that it
      may
      deem necessary or desirable in connection with the servicing and administration
      of the Mortgage Loans, including but not limited to the power and authority
      (i)
      to execute and deliver, on behalf of the Certificateholders and the Trustee,
      customary consents or waivers and other instruments and documents, (ii) to
      consent to transfers of any Mortgaged Property and assumptions of the Mortgage
      Notes and related Mortgages, (iii) 

     

     

    
      
         

      

      
        129

        
          

        

      

      
         

      

    

     

    to
      collect any Insurance Proceeds and Liquidation Proceeds, and (iv) to effectuate
      foreclosure or other conversion of the ownership of the Mortgaged Property
      securing any Mortgage Loan, in each case, in accordance with the provisions
      of
      this Agreement and the Servicing Agreement, as applicable; provided
      that the
      Master Servicer shall not take, or knowingly permit the Servicer to take, any
      action that is inconsistent with or prejudices the interests of the Trust Fund
      or the Certificateholders in any Mortgage Loan or the rights and interests
      of
      the Depositor, the Trustee, the Certificateholders under this Agreement. The
      Master Servicer further is authorized and empowered by the Trustee, on behalf
      of
      the Certificateholders and the Trustee, in its own name or in the name of the
      Servicer (to the extent permitted in the Servicing Agreement), when the Master
      Servicer or the Servicer, as the case may be, believes it is appropriate in
      its
      best judgment to register any Mortgage Loan with MERS, or cause the removal
      from
      the registration of any Mortgage Loan on the MERS system, to execute and
      deliver, on behalf of the Trustee and the Certificateholders or any of them,
      any
      and all instruments of assignment and other comparable instruments with respect
      to such assignment or re-recording of a Mortgage in the name of MERS, solely
      as
      nominee for the Trustee and its successor and assigns. The Master Servicer
      shall
      represent and protect the interests of the Trust Fund in the same manner as
      it
      protects its own interests in mortgage loans in its own portfolio in any claim,
      proceeding or litigation regarding a Mortgage Loan and shall not make or
      knowingly permit the Servicer to make any modification, waiver or amendment
      of
      any term of any Mortgage Loan that would cause an Adverse REMIC Event. Without
      limiting the generality of the foregoing, the Master Servicer in its own name
      or
      in the name of the Servicer, and the Servicer, to the extent such authority
      is
      delegated to the Servicer under the Servicing Agreement, is hereby authorized
      and empowered by the Trustee when the Master Servicer or the Servicer, as the
      case may be, believes it appropriate in its best judgment and in accordance
      with
      Accepted Servicing Practices and the Servicing Agreement, to execute and
      deliver, on behalf of itself and the Certificateholders, the Trustee or any
      of
      them, any and all instruments of satisfaction or cancellation, or of partial
      or
      full release or discharge and all other comparable instruments, with respect
      to
      the Mortgage Loans and with respect to the Mortgaged Properties. The Trustee
      shall furnish to the Master Servicer, upon request, any powers of attorney
      empowering the Master Servicer or the Servicer to execute and deliver
      instruments of satisfaction or cancellation, or of partial or full release
      or
      discharge, and to foreclose upon or otherwise liquidate Mortgaged Property,
      and
      to appeal, prosecute or defend in any court action relating to the Mortgage
      Loans or the Mortgaged Property, in accordance with the Servicing Agreement
      and
      this Agreement, and the Trustee shall execute and deliver such other documents,
      as the Master Servicer may request, necessary or appropriate to enable the
      Master Servicer to master service the Mortgage Loans and carry out its duties
      hereunder and to allow the Servicer to service the Mortgage Loans, in each
      case
      in accordance with Accepted Servicing Practices (and the Trustee shall have
      no
      liability for misuse of any such powers of attorney by the Master Servicer
      or
      the Servicer). If the Master Servicer or the Trustee has been advised that
      it is
      likely that the laws of the state in which action is to be taken prohibit such
      action if taken in the name of the Trustee or that the Trustee would be
      adversely affected under the “doing business” or tax laws of such state if such
      action is taken in its name, then upon request of the Trustee the Master
      Servicer shall join with the Trustee in the appointment of a co-trustee pursuant
      to Section 6.09 hereof. In no event shall the Master Servicer, without the
      Trustee’s written consent: (i) initiate any action, suit or proceeding solely
      under the Trustee’s name without indicating the Master Servicer in its
      applicable, representative capacity, (ii) initiate any action, suit or
      proceeding not directly relating to the servicing of a Mortgage Loan (including
      but not limited to actions, suits or proceedings against Certificateholders,
      or
      against the Depositor or the Seller for breaches of representations and
      warranties) under the Trustee’s name, (iii) engage counsel to represent the
      Trustee in any action, suit or proceeding not directly relating to the servicing
      of a Mortgage Loan (including but not limited to actions, suits or proceedings
      against Certificateholders, or against the Depositor or the Seller for breaches
      of representations and warranties), or (iv) prepare, execute or deliver any
      government filings, forms, permits, registrations or other documents or take
      any
      action with the intent to cause, and that actually causes, the Trustee to be
      registered to do business in any state. The Master Servicer shall indemnify
      the
      Trustee for any and all costs, liabilities and expenses incurred by the Trustee
      in connection with the negligent or willful misuse of such powers of attorney
      by
      the Master Servicer. In the performance of its duties hereunder, the Master
      Servicer shall be an independent contractor and shall not, except in those
      instances where it is taking action in the name of the Trustee on behalf of
      the
      Trust Fund, be deemed to be the agent of the Trustee.

     

    
      
        
        

      

      
        130

        
          

        

      

      
        
        

      

    

     

    (b) In
      master
      servicing and administering the Mortgage Loans, the Master Servicer shall employ
      procedures and exercise the same care that it customarily employs and exercises
      in master servicing and administering loans for its own account, giving due
      consideration to Accepted Servicing Practices where such practices do not
      conflict with this Agreement. Consistent with the foregoing, the Master Servicer
      may, and may permit the Servicer to, in its discretion (i) waive any late
      payment charge (but not any Prepayment Premium, except as set forth below)
      and
      (ii) extend the due dates for payments due on a Mortgage Note for a period
      not
      greater than 120 days; provided,
      however,
      that
      the maturity of any Mortgage Loan shall not be extended past the date on which
      the final payment is due on the latest maturing Mortgage Loan as of the Cut-off
      Date. In the event of any extension described in clause (ii) above, the Master
      Servicer shall make or cause the Servicer (if required by the Servicing
      Agreement) to make Advances on the related Mortgage Loan in accordance with
      the
      provisions of Section 5.04 on the basis of the amortization schedule of such
      Mortgage Loan without modification thereof by reason of such extension.
      Notwithstanding anything to the contrary in this Agreement, the Master Servicer
      shall not make or knowingly permit any modification, waiver or amendment of
      any
      material term of any Mortgage Loan, unless: (1) such Mortgage Loan is in default
      or default by the related Mortgagor is, in the reasonable judgment of the Master
      Servicer or the Servicer, reasonably foreseeable, (2) in the case of a waiver
      of
      a Prepayment Premium, (a) such Mortgage Loan is in default or default by the
      related Mortgagor is, in the reasonable judgment of the Master Servicer or
      the
      Servicer, reasonably foreseeable and such waiver would maximize recovery of
      total proceeds taking into account the value of such Prepayment Premium and
      the
      related Mortgage Loan or (b) if the prepayment is not the result of a refinance
      by the Servicer or any of its affiliates and (i) such Mortgage Loan is in
      default or default by the related Mortgagor is, in the reasonable judgment
      of
      the Master Servicer or the Servicer, reasonably foreseeable and such waiver
      would maximize recovery of total proceeds taking into account the value of
      such
      Prepayment Premium and the related Mortgage Loan or (ii) the collection of
      the
      Prepayment Premium would be in violation of applicable law or (iii) the
      collection of such Prepayment Premium would be considered “predatory” pursuant
      to written guidance published or issued by any applicable federal, state or
      local regulatory authority acting in its official capacity and having
      jurisdiction over such matters and (3) the Master Servicer shall have provided
      or caused to be provided to the Trustee an Opinion of Counsel addressed to
      the
      Trustee (which opinion shall, if provided by the Master Servicer, be an expense
      reimbursed from the Collection Account pursuant to Section 4.02(v)) to the
      effect that such modification, waiver or amendment would not result in an
      Adverse REMIC Event; provided,
      in no
      event shall an Opinion of Counsel be required for the waiver of a Prepayment
      Premium under clause (2) above.

     

    
      
        
        

      

      
        131

        
          

        

      

      
        
        

      

    

     

    
      	 	
              Section
                9.05 

            	
              Enforcement
                of Servicer’s and Master Servicer’s Obligations. 

            


    

     

    (a) The
      Servicing Agreement requires the Servicer to service the Mortgage Loans in
      accordance with the provisions thereof. References in this Agreement to actions
      taken or to be taken by the Master Servicer include actions taken or to be
      taken
      by the Servicer on behalf of the Master Servicer. Any fees and other amounts
      payable to the Servicer shall be deducted from amounts remitted to the Master
      Servicer by the Servicer (to the extent permitted by the Servicing Agreement)
      and shall not be an obligation of the Trust Fund, the Trustee or the Master
      Servicer.

     

    (b) The
      Master Servicer shall not be required to (i) take any action with respect to
      the
      servicing of any Mortgage Loan that the Servicer is not required to take under
      the Servicing Agreement and (ii) cause the Servicer to take any action or
      refrain from taking any action if the Servicing Agreement does not require
      the
      Servicer to take such action or refrain from taking such action; in both cases
      notwithstanding any provision of this Agreement that requires the Master
      Servicer to take such action or cause the Servicer to take such
      action.

     

    (c) The
      Master Servicer, for the benefit of the Trustee and the Certificateholders,
      shall use its reasonable best efforts to enforce the obligations of the Servicer
      under the Servicing Agreement, and shall, upon obtaining actual knowledge of
      the
      failure of the Servicer to perform its obligations in accordance therewith,
      to
      the extent that such non-performance of such obligations would have a material
      adverse effect on a Mortgage Loan, the Trust Fund or the Certificateholders,
      terminate the rights and obligations of the Servicer thereunder and either
      act
      as servicer of the related Mortgage Loans or cause the other parties hereto
      to
      enter into a Servicing Agreement (and such parties hereby agree to execute
      and
      deliver any such successor Servicing Agreement), with a successor Servicer.
      Such
      enforcement, including, without limitation, the legal prosecution of claims,
      termination of the Servicing Agreement and the pursuit of other appropriate
      remedies, shall be in such form and carried out to such an extent and at such
      time as the Master Servicer, in its good faith business judgment, would require
      were it the owner of the related Mortgage Loans. The Master Servicer shall
      pay
      the costs of such enforcement at its own expense, and shall be reimbursed
      therefor initially (i) from a general recovery resulting from such enforcement
      only to the extent, if any, that such recovery exceeds all amounts due in
      respect of the related Mortgage Loans, (ii) from a specific recovery of costs,
      expenses or attorneys’ fees against the party against whom such enforcement is
      directed, and then, (iii) to the extent that such amounts are insufficient
      to
      reimburse the Master Servicer for the costs of such enforcement, from the
      Collection Account.

     

    (d) The
      Master Servicer shall be entitled to conclusively rely on any certifications
      or
      other information provided by the Servicer under the terms of the Servicing
      Agreement, in its preparation of any certifications, filings or reports, in
      accordance with the terms hereof or as may be required by applicable law or
      regulation.

     

    
      	 	
              Section
                9.06 

            	
              Collection
                of Taxes, Assessments and Similar Items. 

            


    

     

    (a) To
      the
      extent provided in the Servicing Agreement, the Master Servicer shall cause
      the
      Servicer to establish and maintain one or more custodial accounts at a
      depository institution (which may be a depository institution with which the
      Master Servicer or the Servicer establishes accounts in the ordinary course
      of
      its servicing activities), the accounts of which are insured to the maximum
      extent permitted by the FDIC (each, an “Escrow Account”) and to deposit therein
      any collections of amounts received with respect to amounts due for taxes,
      assessments, water rates, standard hazard insurance policy premiums, Payaheads,
      if applicable, or any comparable items for the account of the Mortgagors.
      Withdrawals from any Escrow Account may be made (to the extent amounts have
      been
      escrowed for such purpose) only in accordance with the Servicing Agreement.
      The
      Servicer shall be entitled to all investment income not required to be paid
      to
      Mortgagors on any Escrow Account maintained by the Servicer. The Master Servicer
      shall make (or cause to be made) to the extent provided in the Servicing
      Agreement advances to the extent necessary in order to effect timely payment
      of
      taxes, water rates, assessments, standard hazard insurance policy premiums
      or
      comparable items in connection with the related Mortgage Loan (to the extent
      that the Mortgagor is required, but fails, to pay such items), provided
      that it
      or the Servicer has determined that the funds so advanced are recoverable from
      escrow payments, reimbursement pursuant to Section 4.02 or
      otherwise.

     

    
      
        
        

      

      
        132

        
          

        

      

      
        
        

      

    

     

    (b) Costs
      incurred by the Master Servicer or by the Servicer in effecting the timely
      payment of taxes and assessments on the properties subject to the Mortgage
      Loans
      may be added to the amount owing under the related Mortgage Note where the
      terms
      of the Mortgage Note so permit; provided,
      however,
      that
      the addition of any such cost shall not be taken into account for purposes
      of
      calculating the distributions to be made to Certificateholders. Such costs,
      to
      the extent that they are unanticipated, extraordinary costs, and not ordinary
      or
      routine costs shall be recoverable as a Servicing Advance by the Master Servicer
      pursuant to Section 4.02.

     

    
      	 	
              Section
                9.07 

            	
              Termination
                of Servicing Agreement; Successor Servicers. 

            


    

     

    (a) The
      Master Servicer shall be entitled to terminate the rights and obligations of
      the
      Servicer under the Servicing Agreement in accordance with the terms and
      conditions of the Servicing Agreement and without any limitation by virtue
      of
      this Agreement; provided,
      however,
      that in
      the event of termination of the Servicing Agreement by the Master Servicer,
      the
      Master Servicer shall provide for the servicing of the Mortgage Loans by a
      successor Servicer to be appointed as provided in the Servicing
      Agreement.

     

    The
      parties acknowledge that notwithstanding the preceding sentence, there may
      be a
      transition period, not to exceed 90 days, in order to effect the transfer of
      servicing to a successor Servicer. The Master Servicer shall be entitled to
      be
      reimbursed from the Servicer (or by the Trust Fund, if the Servicer is unable
      to
      fulfill its obligations hereunder) for all costs associated with the transfer
      of
      servicing from the predecessor servicer, including without limitation, any
      costs
      or expenses associated with the complete transfer of all servicing data and
      the
      completion, correction or manipulation of such servicing data, as may be
      required by the Master Servicer to correct any errors or insufficiencies in
      the
      servicing data or otherwise to enable the Master Servicer to service the
      Mortgage Loans properly and effectively.

     

    (b) If
      the
      Master Servicer acts as a successor Servicer, it will not assume liability
      for
      the representations and warranties of the Servicer, if any, that it replaces.
      The Master Servicer shall use reasonable efforts to have the successor Servicer
      assume liability for the representations and warranties made by the terminated
      Servicer in the Servicing Agreement, and in the event of any such assumption
      by
      the successor Servicer, the Trustee or the Master Servicer, as applicable,
      may,
      in the exercise of its business judgment, release the terminated Servicer from
      liability for such representations and warranties.

     

    
      
        
        

      

      
        133

        
          

        

      

      
        
        

      

    

     

    (c) If
      the
      Master Servicer acts as a successor Servicer, it will have the same obligations
      to make Advances as the Servicer under the Servicing Agreement and to reimburse
      the successor Servicer for unreimbursed Advances if required by the Servicing
      Agreement but will have no obligation to make an Advance if it determines in
      its
      reasonable judgment that such Advance is non-recoverable. To the extent that
      the
      Master Servicer is unable to find a successor Servicer that is willing to
      service the Mortgage Loans for the Servicing Fee because of the obligation
      of
      the Servicer to make Advances regardless of whether such Advance is recoverable,
      the Servicing Agreement may be amended to provide that the successor Servicer
      shall have no obligation to make an Advance if it determines in its reasonable
      judgment that such Advance is non-recoverable and provides an Officer’s
      Certificate to such effect to the Master Servicer and the Trustee.

     

    
      	 	
              Section
                9.08 

            	
              Master
                Servicer Liable for Enforcement. 

            


    

     

    Notwithstanding
      anything contained in the Servicing Agreement to the contrary, the Master
      Servicer shall remain obligated and liable to the Trustee and the
      Certificateholders in accordance with the provisions of this Agreement, to
      the
      extent of its obligations hereunder, without diminution of such obligation
      or
      liability by virtue of the Servicing Agreement. The Master Servicer shall use
      commercially reasonable efforts to ensure that the Mortgage Loans are serviced
      in accordance with the provisions of this Agreement and shall use commercially
      reasonable efforts to enforce the provisions of the Servicing Agreement for
      the
      benefit of the Certificateholders. The Master Servicer shall be entitled to
      enter into any agreement with the Servicer for indemnification of the Master
      Servicer and nothing contained in this Agreement shall be deemed to limit or
      modify such indemnification. Except as expressly set forth herein, the Master
      Servicer shall have no liability for the acts or omissions of the Servicer
      in
      the performance by the
      Servicer of its obligations under the Servicing Agreement.

     

    
      	 	
              Section
                9.09 

            	
              No
                Contractual Relationship Between the Servicer and Trustee or
                Depositor. 

            


    

     

    The
      Servicing Agreement and any other transactions or services relating to the
      Mortgage Loans involving the Servicer in its capacity as such and not as an
      originator shall be deemed to be between the
      Servicer, the Seller and the Master Servicer, and the Trustee and the Depositor
      shall not be deemed parties thereto and shall have no obligations, duties or
      liabilities with respect to the Servicer except as set forth in Section 9.10
      hereof, but shall have rights thereunder as third party beneficiaries. It is
      furthermore understood and agreed by the parties hereto that the obligations
      of
      the Servicer are set forth in their entirety in the Servicing Agreement and
      the
      Servicer has no obligations under and is not otherwise bound by the terms of
      this Agreement.

     

    
      	 	
              Section
                9.10 

            	
              Assumption
                of Servicing Agreement by Trustee. 

            


    

     

    (a) In
      the
      event the Master Servicer shall for any reason no longer be the Master Servicer
      (including by reason of any Event of Default under this Agreement), after a
      period not to exceed ninety days after the issuance of any notice of termination
      pursuant to Section 6.14 or Section 9.28, as applicable, the Trustee shall,
      in
      accordance with Section 6.14, thereupon assume all of the rights and obligations
      of such Master Servicer hereunder and under the Servicing Agreement entered
      into
      with respect to the Mortgage Loans. The Trustee, its designee or any successor
      master servicer appointed by the Trustee shall be deemed to have assumed all
      of
      the Master Servicer’s interest herein and therein to the same extent as if the
      Servicing Agreement had been assigned to the assuming party, except that the
      Master Servicer shall not thereby be relieved of any liability or obligations
      of
      the Master Servicer under the Servicing Agreement accruing prior to its
      replacement as Master Servicer, and shall be liable to the Trustee, and hereby
      agrees to indemnify and hold harmless the Trustee from and against all costs,
      damages, expenses and liabilities (including reasonable attorneys’ fees)
      incurred by the Trustee as a result of such liability or obligations of the
      Master Servicer and in connection with the Trustee’s assumption (but not its
      performance, except to the extent that costs or liability of the Trustee are
      created or increased as a result of negligent or wrongful acts or omissions
      of
      the Master Servicer prior to its replacement as Master Servicer) of the Master
      Servicer’s obligations, duties or responsibilities thereunder; provided
      that the
      Master Servicer shall not indemnify or hold harmless the Trustee against
      negligent or willful misconduct of the Trustee.

     

    
      
        
        

      

      
        134

        
          

        

      

      
        
        

      

    

     

    (b) The
      Master Servicer that has been terminated shall, upon request of the Trustee
      but
      at the expense of such Master Servicer, deliver to the assuming party all
      documents and records relating to the Servicing Agreement and the related
      Mortgage Loans and an accounting of amounts collected and held by it and
      otherwise use its best efforts to effect the orderly and efficient transfer
      of
      the Servicing Agreement to the assuming party.

     

    
      	 	
              Section
                9.11 

            	
              Due-on-Sale
                Clauses; Assumption Agreements.

            


    

     

    To
      the
      extent provided in the Servicing Agreement, to the extent Mortgage Loans contain
      enforceable due-on-sale clauses, the Master Servicer shall cause the Servicer
      to
      enforce such clauses in accordance with the Servicing Agreement. If applicable
      law prohibits the enforcement of a due-on-sale clause or such clause is
      otherwise not enforced in accordance with the Servicing Agreement, and, as
      a
      consequence, a Mortgage Loan is assumed, the original Mortgagor may be released
      from liability in accordance with the Servicing Agreement.

    
       

      
        	 	
                Section
                  9.12 

              	
                Release
                  of Mortgage Files.

              


      

    

     

    (a) Upon
      (i)
      becoming aware of the payment in full of any Mortgage Loan or (ii) the receipt
      by the Master Servicer of a notification that payment in full has been or will
      be escrowed in a manner customary for such purposes, the Master Servicer shall,
      or shall cause the Servicer to, promptly notify the Trustee (or the applicable
      Custodian) by a certification (which certification shall include a statement
      to
      the effect that all amounts received in connection with such payment that are
      required to be deposited in the Collection Account maintained by the Master
      Servicer pursuant to Section 4.01 have been or will be so deposited) of a
      Servicing Officer and shall request (on the form attached hereto as Exhibit
      C or
      on the form attached to the related Custodial Agreement) the Trustee or the
      applicable Custodian, to deliver to the Servicer the related Mortgage File.
      Upon
      receipt of such certification and request, the Trustee or the applicable
      Custodian (with the consent, and at the direction of the Trustee), shall
      promptly release the related Mortgage File to the Servicer and neither the
      Trustee nor the applicable Custodian shall have any further responsibility
      with
      regard to such Mortgage File. Upon any such payment in full, the Master Servicer
      is authorized, and the Servicer, to the extent such authority is provided for
      under the Servicing Agreement, is authorized, to give, as agent for the Trustee,
      as the mortgagee under the Mortgage that secured the Mortgage Loan, an
      instrument of satisfaction (or assignment of mortgage without recourse)
      regarding the Mortgaged Property subject to the Mortgage, which instrument
      of
      satisfaction or assignment, as the case may be, shall be delivered to the Person
      or Persons entitled thereto against receipt therefor of such payment, it being
      understood and agreed that no expenses incurred in connection with such
      instrument of satisfaction or assignment, as the case may be, shall be
      chargeable to the Collection Account.

     

    
      
        
        

      

      
        135

        
          

        

      

      
        
        

      

    

     

    (b) From
      time
      to time and as appropriate for the servicing or foreclosure of any Mortgage
      Loan
      and in accordance with Accepted Servicing Practices and the Servicing Agreement,
      the Trustee shall execute such documents as shall be prepared and furnished
      to
      the Trustee by the Master Servicer, or by the Servicer (in form reasonably
      acceptable to the Trustee) and as are necessary to the prosecution of any such
      proceedings. The Trustee or the related Custodian, shall, upon request of the
      Master Servicer, or of the Servicer, and delivery to the Trustee or the
      applicable Custodian, of a request for release of documents and a receipt signed
      by a Servicing Officer substantially in the form of Exhibit C, release the
      related Mortgage File held in its possession or control to the Master Servicer
      (or the Servicer). Such receipt shall obligate the Master Servicer or Servicer
      to return the Mortgage File to the Trustee or the applicable Custodian, as
      applicable, when the need therefor by the Master Servicer or Servicer no longer
      exists unless the Mortgage Loan shall be liquidated, in which case, upon receipt
      of a certificate of a Servicing Officer similar to that hereinabove specified,
      the receipt shall be released by the Trustee or the applicable Custodian, as
      applicable, to the Master Servicer (or the Servicer).

     

    
      	 	
              Section
                9.13 

            	
              Documents,
                Records and Funds in Possession of Master Servicer to be Held for
                Trustee. 

            


    

     

    (a) The
      Master Servicer shall transmit, or cause the Servicer to transmit, to the
      Trustee such documents and instruments coming into the possession of the Master
      Servicer or the Servicer from time to time as are required by the terms hereof
      or of the Servicing Agreement to be delivered to the Trustee or the applicable
      Custodian. Any funds received by the Master Servicer or by the Servicer in
      respect of any Mortgage Loan or which otherwise are collected by the Master
      Servicer or the Servicer as Liquidation Proceeds or Insurance Proceeds in
      respect of any Mortgage Loan shall be held for the benefit of the Trustee and
      the Certificateholders subject to the Master Servicer’s right to retain or
      withdraw from the Collection Account the Master Servicing Fee and other amounts
      provided in this Agreement and to the right of the Servicer to retain its
      Servicing Fee and other amounts as provided in the Servicing Agreement. The
      Master Servicer shall, and shall (to the extent provided in the Servicing
      Agreement) cause the Servicer to, provide access to information and
      documentation regarding the Mortgage Loans to the Trustee, its agents and
      accountants at any time upon reasonable request and during normal business
      hours, and to Certificateholders that are savings and loan associations, banks
      or insurance companies, the Office of Thrift Supervision, the FDIC and the
      supervisory agents and examiners of such Office and Corporation or examiners
      of
      any other federal or state banking or insurance regulatory authority if so
      required by applicable regulations of the Office of Thrift Supervision or other
      regulatory authority, such access to be afforded without charge but only upon
      reasonable request in writing and during normal business hours at the offices
      of
      the Master Servicer designated by it. In fulfilling such a request the Master
      Servicer shall not be responsible for determining the sufficiency of such
      information.

     

    
      
        
        

      

      
        136

        
          

        

      

      
        
        

      

    

     

    (b) All
      Mortgage Files and funds collected or held by, or under the control of, the
      Master Servicer or the Servicer, in respect of any Mortgage Loans, whether
      from
      the collection of principal and interest payments or from Liquidation Proceeds
      or Insurance Proceeds, shall be held by the Master Servicer or by the Servicer,
      for and on behalf of the Trustee and the Certificateholders and shall be and
      remain the sole and exclusive property of the Trustee; provided,
      however,
      that
      the Master Servicer and the Servicer shall be entitled to setoff against, and
      deduct from, any such funds any amounts that are properly due and payable to
      the
      Master Servicer or the Servicer under this Agreement or the Servicing Agreement
      and shall be authorized to remit such funds to the Trustee in accordance with
      this Agreement.

     

    (c) The
      Master Servicer hereby acknowledges that concurrently with the execution of
      this
      Agreement, the Trustee shall own or, to the extent that a court of competent
      jurisdiction shall deem the conveyance of the Mortgage Loans from the Seller
      to
      the Depositor not to constitute a sale, the Trustee shall have a security
      interest in the Mortgage Loans and in all Mortgage Files representing such
      Mortgage Loans and in all funds and investment property now or hereafter held
      by, or under the control of, the Servicer or the Master Servicer that are
      collected by the Servicer or the Master Servicer in connection with the Mortgage
      Loans, whether as scheduled installments of principal and interest or as full
      or
      partial prepayments of principal or interest or as Liquidation Proceeds or
      Insurance Proceeds or otherwise, and in all proceeds of the foregoing and
      proceeds of proceeds (but excluding any fee or other amounts to which the
      Servicer is entitled under the Servicing Agreement, or the Master Servicer
      or
      the Depositor is entitled to hereunder); and the Master Servicer agrees that
      so
      long as the Mortgage Loans are assigned to and held by the Trustee or any
      Custodian, all documents or instruments constituting part of the Mortgage Files,
      and such funds relating to the Mortgage Loans which come into the possession
      or
      custody of, or which are subject to the control of, the Master Servicer or
      the
      Servicer shall be held by the Master Servicer or the Servicer for and on behalf
      of the Trustee as the Trustee’s agent and bailee for purposes of perfecting the
      Trustee’s security interest therein as provided by the applicable Uniform
      Commercial Code or other applicable laws.

     

    (d) The
      Master Servicer agrees that it shall not, and shall not authorize the Servicer
      to, create, incur or subject any Mortgage Loans, or any funds that are deposited
      in any Custodial Account, Escrow Account or the Collection Account, or any
      funds
      that otherwise are or may become due or payable to the Trustee, to any claim,
      lien, security interest, judgment, levy, writ of attachment or other
      encumbrance, nor assert by legal action or otherwise any claim or right of
      setoff against any Mortgage Loan or any funds collected on, or in connection
      with, a Mortgage Loan.

     

    
      	 	
              Section
                9.14 

            	
              Representations
                and Warranties of the Master Servicer. 

            


    

     

    (a) The
      Master Servicer hereby represents and warrants to the Depositor and the Trustee,
      for the benefit of the Certificateholders, as of the Closing Date
      that:

     

    (i) it
      is
      validly existing and in good standing under the laws of the state of its
      incorporation, and as Master Servicer has full power and authority to transact
      any and all business contemplated by this Agreement and to execute, deliver
      and
      comply with its obligations under the terms of this Agreement, the execution,
      delivery and performance of which have been duly authorized by all necessary
      corporate action on the part of the Master Servicer;

     

    
      
        
        

      

      
        137

        
          

        

      

      
        
        

      

    

     

    (ii) the
      execution and delivery of this Agreement by the Master Servicer and its
      performance and compliance with the terms of this Agreement will not (A) violate
      the Master Servicer’s charter or bylaws, (B) violate any law or regulation or
      any administrative decree or order to which it is subject or (C) constitute
      a
      default (or an event which, with notice or lapse of time, or both, would
      constitute a default) under, or result in the breach of, any material contract,
      agreement or other instrument to which the Master Servicer is a party or by
      which it is bound or to which any of its assets are subject, which violation,
      default or breach would materially and adversely affect the Master Servicer’s
      ability to perform its obligations under this Agreement;

     

    (iii) this
      Agreement constitutes, assuming due authorization, execution and delivery hereof
      by the other respective parties hereto, a legal, valid and binding obligation
      of
      the Master Servicer, enforceable against it in accordance with the terms hereof,
      except as such enforcement may be limited by bankruptcy, insolvency,
      reorganization, moratorium and other laws affecting the enforcement of
      creditors’ rights in general, and by general equity principles (regardless of
      whether such enforcement is considered in a proceeding in equity or at
      law);

     

    (iv) the
      Master Servicer is not in default with respect to any order or decree of any
      court or any order or regulation of any federal, state, municipal or
      governmental agency to the extent that any such default would materially and
      adversely affect its performance hereunder;

     

    (v) the
      Master Servicer is not a party to or bound by any agreement or instrument or
      subject to any charter provision, bylaw or any other corporate restriction
      or
      any judgment, order, writ, injunction, decree, law or regulation that may
      materially and adversely affect its ability as Master Servicer to perform its
      obligations under this Agreement or that requires the consent of any third
      person to the execution of this Agreement or the performance by the Master
      Servicer of its obligations under this Agreement;

     

    (vi) no
      litigation is pending or, to the best of the Master Servicer’s knowledge,
      threatened against the Master Servicer which would prohibit its entering into
      this Agreement or performing its obligations under this Agreement;

     

    (vii) the
      Master Servicer, or an affiliate thereof the primary business of which is the
      servicing of conventional residential mortgage loans, is a Fannie Mae- or
      Freddie Mac-approved seller/servicer;

     

    (viii) no
      consent, approval, authorization or order of any court or governmental agency
      or
      body is required for the execution, delivery and performance by the Master
      Servicer of or compliance by the Master Servicer with this Agreement or the
      consummation of the transactions contemplated by this Agreement, except for
      such
      consents, approvals, authorizations and orders (if any) as have been
      obtained;

     

    (ix) the
      consummation of the transactions contemplated by this Agreement are in the
      ordinary course of business of the Master Servicer;

     

    
      
        
        

      

      
        138

        
          

        

      

      
        
        

      

    

     

    (x) the
      Master Servicer has obtained an Errors and Omissions Insurance Policy and a
      Fidelity Bond in accordance with Section 9.02 each of which is in full force
      and
      effect, and each of which provides at least such coverage as is required
      hereunder; and

     

    (xi) the
      information about the Master Servicer under the heading “The Master Servicer” in
      the Prospectus relating to the Master Servicer does not include an untrue
      statement of a material fact and does not omit to state a material fact, with
      respect to the statements made, necessary in order to make the statements in
      light of the circumstances under which they were made not
      misleading.

     

    (b) It
      is
      understood and agreed that the representations and warranties set forth in
      this
      Section 9.14 shall survive the execution and delivery of this Agreement. The
      Master Servicer shall indemnify the Depositor and the Trustee and hold them
      harmless against any loss, damages, penalties, fines, forfeitures, legal fees
      and related costs, judgments, and other costs and expenses resulting from any
      claim, demand, defense or assertion based on or grounded upon, or resulting
      from, a breach of the Master Servicer’s representations and warranties contained
      in Section 9.14(a). It is understood and agreed that the enforcement of the
      obligation of the Master Servicer set forth in this Section to indemnify the
      Depositor and the Trustee as provided in this Section constitutes the sole
      remedy (other than as set forth in Section 6.14) of the Depositor and the
      Trustee, respecting a breach of the foregoing representations and warranties.
      Such indemnification shall survive any termination of the Master Servicer as
      Master Servicer hereunder, and any termination of this Agreement.

     

    Any
      cause
      of action against the Master Servicer relating to or arising out of the breach
      of any representations and warranties made in this Section shall accrue upon
      discovery of such breach by any of the Depositor, the Master Servicer or the
      Trustee or notice thereof by any one of such parties to the other parties.
      

     

    (c) It
      is
      understood and agreed that the representations and warranties of the Depositor
      set forth in Sections 2.03(i) through (vi) shall survive the execution and
      delivery of this Agreement. The Depositor shall indemnify the Master Servicer
      and hold each harmless against any loss, damages, penalties, fines, forfeitures,
      legal fees and related costs, judgments, and other costs and expenses resulting
      from any claim, demand, defense or assertion based on or grounded upon, or
      resulting from, a breach of the Depositor’s representations and warranties
      contained in Sections 2.03(i) through (vi) hereof. It is understood and agreed
      that the enforcement of the obligation of the Depositor set forth in this
      Section to indemnify the Master Servicer as provided in this Section constitutes
      the sole remedy hereunder of the Master Servicer respecting a breach by the
      Depositor of the representations and warranties in Sections 2.03(i) through
      (vi)
      hereof.

     

    (d) Any
      cause
      of action against the Master Servicer relating to or arising out of the breach
      of any representations and warranties made in this Section shall accrue upon
      discovery of such breach by either the Depositor, the Master Servicer or the
      Trustee or notice thereof by any one of such parties to the other parties.
      Notwithstanding anything in this Agreement to the contrary, the Master Servicer
      shall not be liable for special, indirect or consequential losses or damages
      of
      any kind whatsoever (including, but not limited to, lost profits); provided,
      however,
      that
      this Subsection 9.14(d) shall not apply in connection with any failure by the
      Master Servicer to comply with the provisions of Sections 9.25 and 9.26
      hereof.

     

    
      
        
        

      

      
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                Section
                  9.15 

              	
                Opinion. 

              


      

    

     

    On
      or
      before the Closing Date, the Master Servicer shall cause to be delivered to
      the
      Depositor, the Seller and the Trustee one or more Opinions of Counsel, dated
      the
      Closing Date, in form and substance reasonably satisfactory to the Depositor
      and
      Lehman Brothers Inc., as to the due authorization, execution and delivery of
      this Agreement by the Master Servicer and the enforceability thereof.


     

    
      	 	
              Section
                9.16 

            	
              Standard
                Hazard and Flood Insurance Policies. 

            


    

     

    For
      each
      Mortgage Loan, the Master Servicer shall maintain, or cause to be maintained
      by
      the Servicer, standard fire and casualty insurance and, where applicable, flood
      insurance, all in accordance with the provisions of this Agreement and the
      Servicing Agreement, as applicable. It is understood and agreed that such
      insurance shall be with insurers meeting the eligibility requirements set forth
      in the Servicing Agreement and that no earthquake or other additional insurance
      is to be required of any Mortgagor or to be maintained on property acquired
      in
      respect of a defaulted loan, other than pursuant to such applicable laws and
      regulations as shall at any time be in force and as shall require such
      additional insurance.

     

    Pursuant
      to Section 4.01, any amounts collected by the Master Servicer, or by the
      Servicer, under any insurance policies maintained pursuant to this Section
      9.16
      or the Servicing Agreement (other than amounts to be applied to the restoration
      or repair of the property subject to the related Mortgage or released to the
      Mortgagor in accordance with the Servicing Agreement) shall be deposited into
      the Collection Account, subject to withdrawal pursuant to Section 4.02. Any
      cost
      incurred by the Master Servicer or the Servicer in maintaining any such
      insurance if the Mortgagor defaults in its obligation to do so shall be added
      to
      the amount owing under the Mortgage Loan where the terms of the Mortgage Loan
      so
      permit; provided,
      however,
      that the
      addition of any such cost shall not be taken into account for purposes of
      calculating the distributions to be made to Certificateholders and shall be
      recoverable by the Master Servicer or the Servicer pursuant to Section
      4.02.

     

    
      	 	
              Section
                9.17 

            	
              Presentment
                of Claims and Collection of Proceeds. 

            


    

     

    The
      Master Servicer shall cause the Servicer (to the extent provided in the
      Servicing Agreement) to, prepare and present on behalf of the Trustee and the
      Certificateholders all claims under the Insurance Policies with respect to
      the
      Mortgage Loans, and take such actions (including the negotiation, settlement,
      compromise or enforcement of the insured’s
      claim)
      as shall be necessary to realize recovery under such policies. Any proceeds
      disbursed to the Master Servicer (or disbursed to the Servicer and remitted
      to
      the Master Servicer) in respect of such policies or bonds shall be promptly
      deposited in the Collection Account or the Custodial Account upon receipt,
      except that any amounts realized that are to be applied to the repair or
      restoration of the related Mortgaged Property as a condition requisite to the
      presentation of claims on the related Mortgage Loan to the insurer under any
      applicable Insurance Policy need not be so deposited (or remitted).

     

    
      
        
        

      

      
        140

        
          

        

      

      
        
        

      

    

    
       

      
        	 	
                Section
                  9.18 

              	
                [Reserved]. 

              


      

      
         

        
          	 	
                  Section
                    9.19 

                	
                  [Reserved]. 

                


        

        
           

          
            	 	
                    Section
                      9.20 

                  	
                    [Reserved]. 

                  


          

           

        

      

    

    
      	 	
              Section
                9.21 

            	
              Compensation
                to the Master Servicer. 

            


    

     

    The
      Master Servicer shall be entitled to withdraw from the Collection Account,
      subject to Section 5.05, the Master Servicing Fee to the extent permitted by
      Section 4.02. Servicing compensation in the form of assumption fees, if any,
      late payment charges, as collected, if any, or otherwise (but not including
      any
      Prepayment Premium) shall be retained by the Master Servicer (or the Servicer)
      and shall not be deposited in the Collection Account. If the Master Servicer
      does not retain or withdraw the Master Servicing Fee from the Collection Account
      as provided herein, the Master Servicer shall be entitled to direct the Trustee
      to pay the Master Servicing Fee to such Master Servicer by withdrawal from
      the
      Certificate Account to the extent that payments have been received with respect
      to the applicable Mortgage Loan. The Master Servicer shall be required to pay
      all expenses incurred by it in connection with its activities hereunder and
      shall not be entitled to reimbursement therefor except as provided in this
      Agreement. Pursuant to Section 4.01(e), all income and gain realized from any
      investment of funds in the Collection Account shall be for the benefit of the
      Master Servicer as additional compensation. The provisions of this Section
      9.21
      are subject to the provisions of Section 6.14.

     

    
      	 	
              Section
                9.22 

            	
              REO
                Property. 

            


    

     

    (a) In
      the
      event the Trust Fund acquires ownership of any REO Property in respect of any
      Mortgage Loan, the deed or certificate of sale shall be issued to the Trustee,
      or to its nominee, on behalf of the Certificateholders. The Master Servicer
      shall use its reasonable best efforts to sell, or cause the Servicer, to the
      extent provided in the Servicing Agreement any REO Property as expeditiously
      as
      possible and in accordance with the provisions of this Agreement and the
      Servicing Agreement, as applicable, but in all events within the time period,
      and subject to the conditions set forth in Article X hereof. Pursuant to its
      efforts to sell such REO Property, the Master Servicer shall protect and
      conserve, or cause the Servicer to protect and conserve, such REO Property
      in
      the manner and to such extent required by the Servicing Agreement, subject
      to
      Article X hereof.

     

    (b) The
      Master Servicer shall deposit or cause to be deposited all funds collected
      and
      received by it, or recovered from the Servicer, in connection with the operation
      of any REO Property in the Collection Account.

     

    (c) The
      Master Servicer and the Servicer, upon the final disposition of any REO
      Property, shall be entitled to reimbursement for any related unreimbursed
      Advances and other unreimbursed advances as well as any unpaid Master Servicing
      Fees or Servicing Fees from Liquidation Proceeds received in connection with
      the
      final disposition of such REO Property; provided
      that
      (without limitation of any other right of reimbursement that the Master Servicer
      or the Servicer shall have hereunder) any such unreimbursed Advances as well
      as
      any unpaid Net Master Servicing Fees or Servicing Fees may be reimbursed or
      paid, as the case may be, prior to final disposition, out of any net rental
      income or other net amounts derived from such REO Property.

     

    
      
        
        

      

      
        141

        
          

        

      

      
        
        

      

    

     

    (d) The
      Liquidation Proceeds from the final disposition of the REO Property, net of
      any
      payment to the Master Servicer and the Servicer as provided above, shall be
      deposited in the Collection Account on or prior to the Determination Date in
      the
      month following receipt thereof and be remitted by wire transfer in immediately
      available funds on the next succeeding Master Servicer Remittance Date to the
      Trustee for deposit into the Certificate Account.

     

    
      	 	
              Section
                9.23 

            	
              Notice
                to the Sponsor, the Depositor and the Trustee. 

            


    

     

    (a) The
      Master Servicer shall promptly notify the Trustee, the Sponsor and the Depositor
      (i) of any legal proceedings pending against the Master Servicer of the type
      described in Item 1117 (Sec. 229.1117) of Regulation AB and (ii) if the Master
      Servicer shall become (but only to the extent not previously disclosed to the
      Master Servicer and the Depositor) at any time an affiliate of any of the
      parties listed on Exhibit V hereto or any of their affiliates. On or before
      March 1st
      of each
      year, the Depositor shall distribute the information in Exhibit V to the Master
      Servicer.

     

    (b) Not
      later
      than four Business Days prior to the Distribution Date of each month, the Master
      Servicer shall provide to the Trustee, the Sponsor and the Depositor notice
      of
      the occurrence of any material modifications, extensions or waivers of terms,
      fees, penalties or payments relating to the Mortgage Loans during the related
      Collection Period or that have cumulatively become material over time (Item
      1121(a)(11) of Regulation AB) along with all information, data, and materials
      related thereto as may be required to be included in the related Distribution
      Report on Form 10-D. The parties to this Agreement acknowledge that the
      performance by the Master Servicer of its duties under this Section 9.23(b)
      related to the timely preparation and delivery of such information is contingent
      upon the Servicer strictly observing all requirements and deadlines in the
      performance of its duties under the Servicing Agreement. The Master Servicer
      shall have no liability for any loss, expense, damage or claim arising out
      of or
      with respect to any failure to properly prepare and/or timely deliver all such
      information where such failure results from the Master Servicer’s inability or
      failure to obtain or receive, on a timely basis, any information from the
      Servicer needed to prepare or deliver such information, which failure does
      not
      result from the Master Servicer’s own negligence, bad faith or willful
      misconduct.

     

    
      	 	
              Section
                9.24 

            	
              Reports
                to the Trustee. 

            


    

     

    (a) Not
      later
      than 30 days after each Distribution Date, the Master Servicer shall, upon
      request, forward to the Trustee a statement, deemed to have been certified
      by a
      Servicing Officer, setting forth the status of the Collection Account maintained
      by the Master Servicer as of the close of business on the related Distribution
      Date, indicating that all distributions required by this Agreement to be made
      by
      the Master Servicer have been made (or if any required distribution has not
      been
      made by the Master Servicer, specifying the nature and status thereof) and
      showing, for the period covered by such statement, the aggregate of deposits
      into and withdrawals from the Collection Account maintained by the Master
      Servicer. Copies of such statement shall be provided by the Master Servicer,
      upon request, to the Depositor, Attention: Contract Finance, and any
      Certificateholders (or by the Trustee at the Master Servicer’s expense if the
      Master Servicer shall fail to provide such copies to the Certificateholders
      (unless (i) the Master Servicer shall have failed to provide the Trustee with
      such statement or (ii) the Trustee shall be unaware of the Master Servicer’s
      failure to provide such statement)).

     

    
      
        
        

      

      
        142

        
          

        

      

      
        
        

      

    

     

    (b) Not
      later
      than two Business Days following each Distribution Date, the Master Servicer
      shall deliver to one Person designated by the Depositor, in a format consistent
      with other electronic loan level reporting supplied by the Master Servicer
      in
      connection with similar transactions, “loan level” information with respect to
      the Mortgage Loans as of the related Determination Date, to the extent that
      such
      information has been provided to the Master Servicer by the Servicer or by
      the
      Depositor.

     

    (c) All
      information, reports and statements prepared by the Master Servicer under this
      Agreement shall be based on information supplied to the Master Servicer by
      the
      Servicer without independent verification thereof and the Master Servicer shall
      be entitled to rely on such information.

     

    
      	 	
              Section
                9.25 

            	
              Assessment
                of Compliance and Attestation
                Reports.

            


    

     

    (a) Assessment
      of Compliance

     

    (i) By
      March
      15 of each year, commencing in March 2007, the Master Servicer and the Credit
      Risk Manager, each at its own expense, shall furnish, and each such party shall
      cause any Servicing Function Participant engaged by it to furnish, each at
      its
      own expense, to the Sponsor, the Depositor, the Master Servicer and the Trustee,
      a report on an assessment of compliance with the Relevant Servicing Criteria
      that contains (A) a statement by such party of its responsibility for assessing
      compliance with the Relevant Servicing Criteria, (B) a statement that such
      party
      used the Servicing Criteria to assess compliance with the Relevant Servicing
      Criteria, (C) such party’s assessment of compliance with the Relevant Servicing
      Criteria as of and for the fiscal year covered by the Form 10-K required to
      be
      filed pursuant to Section 6.20(e), including, if there has been any material
      instance of noncompliance with the Relevant Servicing Criteria, a discussion
      of
      each such failure and the nature and status thereof, and (D) a statement that
      a
      registered public accounting firm has issued an attestation report on such
      party’s assessment of compliance with the Relevant Servicing Criteria as of and
      for such period. 

     

    (ii) When
      the
      Master Servicer and the Credit Risk Manager (or any Servicing Function
      Participant engaged by the Master Servicer) submits its assessments to the
      Trustee and the Master Servicer, such parties will also at such time include
      the
      assessment (and attestation pursuant to subsection (b) of this Section 9.25)
      of
      each Servicing Function Participant engaged by it and shall indicate to the
      Depositor what Relevant Servicing Criteria will be addressed in any such reports
      prepared by any such Servicing Function Participant.

     

    (iii) Promptly
      after receipt of each report on assessment of compliance, the Exchange Act
      Signing Party shall confirm that the assessments, taken as a whole, address
      all
      applicable Servicing Criteria and taken individually address the Relevant
      Servicing Criteria (and disclose the inapplicability of the Servicing Criteria
      not determined to be Relevant Criteria) for each party as set forth on Exhibit
      T
      and on any similar exhibit set forth in the Servicing Agreement in respect
      of
      the Servicer, and the applicable Custodial Agreement in respect of any
      Custodian, and shall notify the Depositor of any exceptions.

     

    
      
        
        

      

      
        143

        
          

        

      

      
        
        

      

    

     

    (b) Attestation
      Reports

     

    (i) By
      March
      15 of each year for so long as the Depositor is subject to Exchange Act
      reporting requirements for the Structured Asset Securities Corporation Mortgage
      Loan Trust 2006-S4, commencing in March 2007, the Master Servicer and the Credit
      Risk Manager, each at its own expense, shall cause, and each such party shall
      cause any Servicing Function Participant engaged by it to cause, each at its
      own
      expense, a registered public accounting firm (which may also render other
      services to the Master Servicer and the Credit Risk Manager, as the case may
      be)
      that is a member of the American Institute of Certified Public Accountants
      to
      furnish a report to the Sponsor, the Depositor, the Master Servicer and the
      Trustee, to the effect that (A) it has obtained a representation regarding
      certain matters from the management of such party, which includes an assertion
      that such party has complied with the Relevant Servicing Criteria, and (B)
      on
      the basis of an examination conducted by such firm in accordance with standards
      for attestation engagements issued or adopted by the PCAOB, it is expressing
      an
      opinion as to whether such party’s compliance with the Relevant Servicing
      Criteria was fairly stated in all material respects, or it cannot express an
      overall opinion regarding such party’s assessment of compliance with the
      Relevant Servicing Criteria. In the event that an overall opinion cannot be
      expressed, such registered public accounting firm shall state in such report
      why
      it was unable to express such an opinion. Such report must be available for
      general use and not contain restricted use language.

     

    (ii) Promptly
      after receipt of such report from the Master Servicer, the Credit Risk Manager
      or any Servicing Function Participant engaged by such parties, the Exchange
      Act
      Signing Party shall confirm that each assessment submitted pursuant subsection
      (a) of this Section 9.25 is coupled with an attestation meeting the requirements
      of this Section and notify the Depositor of any exceptions.

     

    
      	 	
              Section
                9.26 

            	
              Annual
                Statement of Compliance with Applicable Servicing
                Criteria. 

            


    

     

    (a) The
      Master Servicer shall deliver (and the Master Servicer shall cause any
      Additional Servicer engaged by it to deliver) to the Sponsor, the Depositor
      and
      the Trustee on or before March 15 of each year, commencing in March 2007, an
      Officer’s Certificate stating, as to the signer thereof, that (A) a review of
      such party’s activities during the preceding calendar year or portion thereof
      and of such party’s performance under this Agreement, or such other applicable
      agreement in the case of an Additional Servicer, has been made under such
      officer’s supervision and (B) to the best of such officer’s knowledge, based on
      such review, such party has fulfilled all its obligations under this Agreement,
      or such other applicable agreement in the case of an Additional Servicer, in
      all
      material respects throughout such year or portion thereof, or, if there has
      been
      a failure to fulfill any such obligation in any material respect, specifying
      each such failure known to such officer and the nature and status
      thereof.

     

    Copies
      of
      such statements shall be provided to any Certificateholder upon request, by
      the
      Master Servicer or by the Trustee at the Master Servicer’s
      expense if the Master Servicer failed to provide such copies (unless (i) the
      Master Servicer shall have failed to provide the Trustee with such statement
      or
      (ii) the Trustee shall be unaware of the Master Servicer’s failure to provide
      such statement).

     

    
      
        
        

      

      
        144

        
          

        

      

      
        
        

      

    

     

    (b) The
      Master Servicer shall notify the Trustee, the Depositor and the Sponsor within
      five (5) days of knowledge thereof (i) of any legal proceedings pending against
      the Master Servicer of the type described in Item 1117 (Sec. 229.1117) of
      Regulation AB and (ii) if the Master Servicer shall become (but only to the
      extent not previously disclosed) at any time an affiliate of any of the parties
      listed on Exhibit V to this Agreement. On or before March 1st
      of each
      year, the Depositor shall distribute the information in Exhibit V to the Master
      Servicer.

     

    
      	 	
              Section
                9.27 

            	
              Merger
                or Consolidation. 

            


    

     

    Any
      Person into which the Master Servicer may be merged or consolidated, or any
      Person resulting from any merger, conversion, other change in form or
      consolidation to which the Master Servicer shall be a party, or any Person
      succeeding to the business of the Master Servicer, shall be the successor to
      the
      Master Servicer hereunder, without the execution or filing of any paper or
      any
      further act on the part of any of the parties hereto, anything herein to the
      contrary notwithstanding; provided,
      however,
      that the
      successor or resulting Person to the Master Servicer shall be a Person that
      shall be qualified and approved to service mortgage loans for Fannie Mae or
      Freddie Mac and shall have a net worth of not less than
      $15,000,000.

     

    
      	 	
              Section
                9.28 

            	
              Resignation
                of Master Servicer. 

            


    

     

    Except
      as
      otherwise provided in Sections 9.27 and 9.29 hereof, the Master Servicer shall
      not resign from the obligations and duties hereby imposed on it unless it
      determines that the Master Servicer’s
      duties
      hereunder are no longer permissible under applicable law or are in material
      conflict by reason of applicable law with any other activities carried on by
      it
      and cannot be cured. Any such determination permitting the resignation of the
      Master Servicer shall be evidenced by an Opinion of Counsel that shall be
      Independent to such effect delivered to the Trustee. No such resignation shall
      become effective until a period of time not to exceed 90 days after the Trustee
      receives written notice thereof from the Master Servicer and until the Trustee
      shall have assumed, or a successor master servicer shall have been appointed
      by
      the Trustee and until such successor shall have assumed, the Master Servicer’s
      responsibilities and obligations under this Agreement. Notice of such
      resignation shall be given promptly by the Master Servicer and the Depositor
      to
      the Trustee.

     

    
      	 	
              Section
                9.29 

            	
              Assignment
                or Delegation of Duties by the Master Servicer. 

            


    

     

    (a) Except
      as
      expressly provided herein, the Master Servicer shall not assign or transfer
      any
      of its rights, benefits or privileges hereunder to any other Person, or delegate
      to or subcontract with, or authorize or appoint any Subservicer, Subcontractor
      or other Person to perform any of the duties, covenants or obligations to be
      performed by the Master Servicer hereunder; provided,
      however,
      that the
      Master Servicer shall have the right without the prior written consent of the
      Trustee or the Depositor to delegate or assign to or subcontract with or
      authorize or appoint an Affiliate of the Master Servicer to perform and carry
      out any duties, covenants or obligations to be performed and carried out by
      the
      Master Servicer hereunder. In no case, however, shall any such delegation,
      subcontracting or assignment to an Affiliate of the Master Servicer relieve
      the
      Master Servicer of any liability hereunder. Notice of such permitted assignment,
      and the name of any such affiliated Subcontractor or Subservicer shall be given
      promptly by the Master Servicer to the Depositor and the Trustee. If, pursuant
      to any provision hereof, the duties of the Master Servicer are transferred
      to a
      successor master servicer, the entire amount of the Master Servicing Fees and
      other compensation payable to the Master Servicer pursuant hereto, including
      amounts payable to or permitted to be retained or withdrawn by the Master
      Servicer pursuant to Section 9.21 hereof, shall thereafter be payable to such
      successor master servicer.

     

    
      
        
        

      

      
        145

        
          

        

      

      
        
        

      

    

     

    (b) At
      any
      time during the period that a Form 10-K is being filed with respect to the
      Trust
      Fund in accordance with the Exchange Act and the rules and regulations of the
      Commission, the Master Servicer shall not permit a Subservicer to perform any
      master servicing responsibilities hereunder with respect to the Mortgage Loans
      unless that Subservicer first agrees in writing with such Master Servicer to
      deliver an assessment of compliance and an accountant’s attestation in such
      manner and at such times in compliance with Sections 9.25(a)(ii) and (b)(ii)
      of
      this Agreement. 

     

    
      	 	
              Section
                9.30 

            	
              Limitation
                on Liability of the Master Servicer and
                Others.

            


    

     

    (a) The
      Master Servicer undertakes to perform such duties and only such duties as are
      specifically set forth in this Agreement. 

     

    (b) No
      provision of this Agreement shall be construed to relieve the Master Servicer
      from liability for its own negligent action, its own negligent failure to act
      or
      its own willful misconduct; provided,
      however,
      that
      the duties and obligations of the Master Servicer shall be determined solely
      by
      the express provisions of this Agreement, the Master Servicer shall not be
      liable except for the performance of such duties and obligations as are
      specifically set forth in this Agreement; no implied covenants or obligations
      shall be read into this Agreement against the Master Servicer and, in absence
      of
      bad faith on the part of the Master Servicer, the Master Servicer may
      conclusively rely, as to the truth of the statements and the correctness of
      the
      opinions expressed therein, upon any certificates or opinions furnished to
      the
      Master Servicer and conforming to the requirements of this
      Agreement.

     

    (c) None
      of
      the Master Servicer, the Seller or the Depositor or any of the directors,
      officers, employees or agents of any of them shall be under any liability to
      the
      Trustee or the Certificateholders for any action taken or for refraining from
      the taking of any action in good faith pursuant to this Agreement, or for errors
      in judgment; provided,
      however,
      that
      this provision shall not protect the Master Servicer, the Seller or the
      Depositor or any such person against any liability that would otherwise be
      imposed by reason of willful misfeasance, bad faith or negligence in its
      performance of its duties or by reason of reckless disregard for its obligations
      and duties under this Agreement. The Master Servicer and any director, officer,
      employee or agent of any of them shall be entitled to indemnification by the
      Trust Fund and will be held harmless against any loss, liability or expense
      incurred in connection with any legal action relating to this Agreement or
      the
      Certificates other than any loss, liability or expense incurred by reason of
      willful misfeasance, bad faith or negligence in the performance of its duties
      hereunder or by reason of reckless disregard of his or its obligations and
      duties hereunder. The Master Servicer, the Seller and the Depositor and any
      director, officer, employee or agent of any of them may rely in good faith
      on
      any document of any kind prima facie properly executed and submitted by any
      Person respecting any matters arising hereunder. The Master Servicer, the Seller
      and the Depositor shall be under no obligation to appear in, prosecute or defend
      any legal action that is not incidental to its duties to master service the
      Mortgage Loans in accordance with this Agreement and that in its opinion may
      involve it in any expenses or liability; provided,
      however,
      that
      the Master Servicer may in its sole discretion undertake any such action that
      it
      may deem necessary or desirable in respect to this Agreement and the rights
      and
      duties of the parties hereto and the interests of the Certificateholders
      hereunder. In such event, the legal expenses and costs of such action and any
      liability resulting therefrom shall be expenses, costs and liabilities of the
      Trust Fund and the Master Servicer shall be entitled to be reimbursed therefor
      out of the Collection Account it maintains as provided by Section
      4.02.

     

    
      
        
        

      

      
        146

        
          

        

      

      
        
        

      

    

     

    
      	 	
              Section
                9.31 

            	
              Indemnification;
                Third-Party Claims. 

            


    

     

    The
      Master Servicer agrees to indemnify the Depositor, the Sponsor and the Trustee
      and their respective officers, directors, agents, employees and affiliates,
      and
      hold each of them harmless against any and all claims, losses, penalties, fines,
      forfeitures, reasonable legal fees and related costs, judgments, and any other
      costs, liability, fees and expenses that the Depositor, the Sponsor or the
      Trustee may sustain arising
      out of or based upon (a) any material breach by the Master Servicer of any
      if
      its obligations hereunder, including particularly its obligations to provide
      any
      reports under Section 9.25(a), Section 9.25(b) or Section 9.26 or any
      information, data or materials required to be included in any Exchange Act
      report, provided,
      however,
      that in
      no event shall the Master Servicer be liable for any special, consequential,
      indirect or punitive damages pursuant to this Section 9.31, even if advised
      of
      the possibility of such damages, (b) any material misstatement or omission
      in
      any information, data or materials provided by the Master Servicer, or (c)
      the
      negligence, bad faith or willful misconduct of the Master Servicer in connection
      with its performance hereunder. The Depositor, the Sponsor and the Trustee
      shall
      immediately notify the Master Servicer if a claim is made by a third party
      with
      respect to this Agreement or the Mortgage Loans entitling the Depositor, the
      Sponsor or the Trustee to indemnification hereunder, whereupon the Master
      Servicer shall assume the defense of any such claim and pay all expenses in
      connection therewith, including counsel fees, and promptly pay, discharge and
      satisfy any judgment or decree which may be entered against it or them in
      respect of such claim. This indemnification shall survive the termination of
      this Agreement or the termination of the Master Servicer as a party to this
      Agreement.

    
       

      
        	 	
                Section
                  9.32 

              	
                [Reserved]. 

              


      

      
         

        
          	 	
                  Section
                    9.33 

                	
                  [Reserved]. 

                


        

         

      

    

    
      	 	
              Section
                9.34 

            	
              Duties
                of the Credit Risk Manager. 

            


    

     

    (a) The
      Certificateholders, by their purchase and acceptance of the Certificates,
      appoint Clayton Fixed Income Services Inc. as Credit Risk Manager. For and
      on
      behalf of the Depositor, the Credit Risk Manager will provide reports and
      recommendations concerning certain delinquent and defaulted Mortgage Loans,
      and
      as to the collection of any Prepayment Premiums with respect to the Mortgage
      Loans. Such reports and recommendations will be based upon information provided
      pursuant to the Credit Risk Management Agreements to the Credit Risk Manager
      by
      the Servicer. The Credit Risk Manager shall look solely to the Servicer and/or
      the Master Servicer for all information and data (including loss and delinquency
      information and data) and loan level information and data relating to the
      servicing of the Mortgage Loans and the Trustee shall not have any obligation
      to
      provide any such information to the Credit Risk Manager and shall not otherwise
      have any responsibility under the Credit Risk Management
      Agreements.

     

    
      
        
        

      

      
        147

        
          

        

      

      
        
        

      

    

     

    (b) On
      or
      about the 15th
      calendar
      day of each month, the Credit Risk Manager shall have prepared and shall make
      available to the Trustee, the Swap Counterparty and each Certificateholder,
      the
      following reports (each such report to be made in a format compatible with
      EDGAR
      filing requirements):

     

    (i) Watchlist
      Report:
      A
      listing of individual Mortgage Loans that are of concern to the Credit Risk
      Manager. Each Watchlist Report shall contain a listing of Mortgage Loans in
      any
      delinquency status, including current and paid-off loans, and may contain the
      comments of the Credit Risk Manager in its sole discretion. The Watchlist Report
      shall be presented in substantially the same format attached hereto as Exhibit
      S-1;

     

    (ii) Loss
      Severity Report:
      A
      compilation and summary of all losses, indicating the loan loss severity for
      the
      Mortgage Loans. Each Loss Severity Report shall include detail of all losses
      reported by the Servicer or the Master Servicer as Realized Losses, except
      those
      for which the Servicer or the Master Servicer has not provided detail adequate
      for reporting purposes. The Loss Severity Report shall be presented in
      substantially the same format attached hereto as Exhibit S-2;

     

    (iii) Prepayment
      Premiums Report:
      A
      summary of Prepayment Premiums assessed or waived by the Servicer. The
      Prepayment Premiums Report shall be presented in substantially the same format
      attached hereto as Exhibit S-3; and

     

    (iv) Analytics
      Report:
      Analytics Reports shall include statistical and/or graphical portrayals
      of:

     

    (1) Delinquency
      Trend:
      The
      delinquency trend, over time, of the Mortgage Loans;

     

    (2) Prepayment
      Analysis:
      The
      constant prepayment rate “CPR” experience of the Mortgage Loans;
      and

     

    (3)  Standard
      Default Assumption:
      The
      Standard Default Assumption experience of the Mortgage Loans.

     

    The
      Analytics Report shall be presented in substantially the same format attached
      hereto as Exhibit S-4.

     

    The
      Credit Risk Manager shall make such reports and any additional information
      reasonably requested by the Depositor available each month to
      Certificateholders, the Trustee and the Rating Agencies via the Credit Risk
      Manager’s
      internet website. The Credit Risk Manager’s internet website shall initially be
      located at http://reports.clayton.com.
      The
      user name for access to the website shall be the Certificateholder’s email
      address and the password shall be “SASCO 2006-S4.” The Trustee shall not have
      any obligation to review such reports or otherwise monitor or supervise the
      activities of the Credit Risk Manager.

     

    
      
        
        

      

      
        148

        
          

        

      

      
        
        

      

    

     

    (c) [Reserved].

     

    (d) The
      Credit Risk Manager shall reasonably cooperate with the Depositor and the
      Exchange Act Signing Party in connection with the Trust Fund’s satisfying the
      reporting requirements under the Exchange Act with respect to reports prepared
      by the Credit Risk Manager.

     

    (e) The
      Credit Risk Manager has not and shall not engage any Subcontractor without
      (a)
      giving notice to the Sponsor, the Trustee, the Master Servicer and the Depositor
      and (b) requiring any such Subcontractor to provide to the Credit Risk Manager
      an assessment report as provided for in Section 9.25(a) above and an attestation
      report as provided in Section 9.25(b) above, which reports the Credit Risk
      Manager shall include in its assessment and attestation reports.

     

    (f) By
      March
      15 of each year (or if such day is not a Business Day, the immediately preceding
      Business Day), the Credit Risk Manager shall deliver a signed certification,
      in
      the form attached hereto as Exhibit U (the “Credit Risk Manager Certification”),
      for the benefit of the Depositor, the Sponsor, the Master Servicer and the
      Trustee and for the benefit of the Person(s) signing the Form 10-K
      Certification; provided
      (i) that
      the Credit Risk Manager Certification shall be so provided by March 15 of such
      year only to the extent that the Depositor delivers a draft (without exhibits)
      of the applicable Annual Report on Form 10-K to the Credit Risk Manager by
      the
      tenth calendar day in March of such year and (ii) in the event that the
      Depositor delivers the draft Form 10-K referred to in clause (i) after the
      tenth
      calendar day in March of such year, the Credit Risk Manager shall deliver the
      Credit Risk Manager Certification as soon as practicable but no later than
      five
      calendar days of delivery to the Credit Risk Manager of such draft Form
      10-K.

     

    (g) In
      the
      event that prior to the filing date of the Form 10-K in March of each year,
      the
      Credit Risk Manager has knowledge or information material to the Credit Risk
      Manager Certification, the Credit Risk Manager shall promptly notify the
      Depositor and the Trustee, in writing. 

     

    
      	 	
              Section
                9.35 

            	
              Limitation
                Upon Liability of the Credit Risk Manager. 

            


    

     

    Except
      as
      provided pursuant to Section 9.36 of this Agreement, neither the Credit Risk
      Manager, nor any of the directors, officers, employees or agents of the Credit
      Risk Manager, shall be under any liability to the Trustee, the
      Certificateholders or the Depositor for any action taken or for refraining
      from
      the taking of any action in good faith pursuant to this Agreement, in reliance
      upon information provided by the Servicer under the Credit Risk Management
      Agreements or for errors in judgment; provided, however,
      that
      this provision shall not protect the Credit Risk Manager or any such person
      against liability that would otherwise be imposed by reason of willful
      malfeasance, bad faith or gross negligence in its performance of its duties
      or
      by reason of reckless disregard for its obligations and duties under this
      Agreement or the Credit Risk Management Agreements. The Credit Risk Manager
      and
      any director, officer, employee or agent of the Credit Risk Manager may rely
      in
      good faith on any document of any kind prima facie properly executed and
      submitted by any Person respecting any matters arising hereunder, and may rely
      in good faith upon the accuracy of information furnished by the Servicer
      pursuant to the Credit Risk Management Agreements in the performance of its
      duties thereunder and hereunder.

     

    
      
        
        

      

      
        149

        
          

        

      

      
        
        

      

    

     

    
      	 	
              Section
                9.36 

            	
              Indemnification
                by the Credit Risk Manager.

            


    

     

    The
      Credit Risk Manager agrees to indemnify the Depositor, the Master Servicer
      and
      the Trustee, and each of their respective directors, officers, employees and
      agents and the Trust Fund and hold each of them harmless from and against any
      losses, damages, penalties, fines, forfeitures, legal fees and expenses and
      related costs, judgments, and any other costs, fees and expenses that any of
      them may sustain arising out of or based upon the engagement of any
      Subcontractor in violation of Section 9.34(f) or any failure by the Credit
      Risk
      Manager to deliver any information, report, certification,
      accountants’
letter
      or other material when and as required under this Agreement, including any
      report under Sections 9.25(a) or (b).

     

    
      	 	
              Section
                9.37 

            	
              Removal
                of Credit Risk Manager.

            


    

     

    The
      Credit Risk Manager may be removed as Credit Risk Manager by Certificateholders
      holding not less than a 66-2/3% Voting Interests in the Trust, in the exercise
      of its or their sole discretion, at any time, without cause, upon ten (10)
      days
      prior written notice. The Certificateholders shall provide such written notice
      to the Trustee and upon receipt of such notice, the Trustee shall provide
      written notice to the Credit Risk Manager of its removal, effective upon receipt
      of such notice.

     

    ARTICLE
      X

     

    REMIC
      ADMINISTRATION

     

    
      	 	
              Section
                10.01 

            	
              REMIC
                Administration.  

            


    

     

    (a) REMIC
      elections as set forth in the Preliminary Statement shall be made on Forms
      1066
      or other appropriate federal tax or information return for the taxable year
      ending on the last day of the calendar year in which the Certificates are
      issued. The regular interests and residual interest in each REMIC shall be
      as
      designated in the Preliminary Statement. For purposes of such designations,
      the
      interest rate of any regular interest that is computed by taking into account
      the weighted average of the Net Mortgage Rates of the Mortgage Loans shall
      be
      reduced by the amount of any expense paid by the Trust to the extent that (i)
      such expense was not taken into account in computing the Net Mortgage Rate
      of
      any Mortgage Loan, (ii) such expense does not constitute an “unanticipated
      expense” of a REMIC within the meaning of Treasury Regulation Section
      1.860G-1(b)(3)(ii) and (iii) the amount of such expense was not taken into
      account in computing the interest rate of a more junior Class of regular
      interests.

     

    (b) The
      Closing Date is hereby designated as the “Startup Day” of each REMIC within the
      meaning of section 860G(a)(9) of the Code. The latest possible maturity date
      for
      purposes of Treasury Regulation 1.860G-1(a)(4) will be the Latest Possible
      Maturity Date.

     

    (c) The
      Trustee shall represent the Trust Fund in any administrative or judicial
      proceeding relating to an examination or audit by any governmental taxing
      authority with respect thereto. The Trustee shall pay any and all tax related
      expenses (not including taxes) of each REMIC, including but not limited to
      any
      professional fees or expenses related to audits or any administrative or
      judicial proceedings with respect to such REMIC that involve the Internal
      Revenue Service or state tax authorities, but only to the extent that (i) such
      expenses are ordinary or routine expenses, including expenses of a routine
      audit
      but not expenses of litigation (except as described in (ii)); or (ii) such
      expenses or liabilities (including taxes and penalties) are attributable to
      the
      negligence or willful misconduct of the Trustee in fulfilling its duties
      hereunder (including its duties as tax return preparer). The Trustee shall
      be
      entitled to reimbursement of expenses to the extent provided in clause (i)
      above
      from the Certificate Account, provided,
      however,
      the
      Trustee shall not be entitled to reimbursement for expenses incurred in
      connection with the preparation of tax returns and other reports as required
      by
      Section 6.20 and this Section.

     

    
      
        
        

      

      
        150

        
          

        

      

      
        
        

      

    

     

    (d) The
      Trustee shall prepare, the Trustee shall sign, and the Trustee will file, all
      of
      each REMIC’s federal and applicable state tax and information returns as such
      REMIC’s direct representative. As used herein, applicable state tax and
      information returns shall mean returns as may be required by the laws of any
      state the applicability of which to the Trust Fund shall have been confirmed
      to
      the Trustee in writing either by the delivery to the Trustee of an Opinion
      of
      Counsel to such effect, or by delivery to the Trustee of a written notification
      to such effect by the taxing authority of such state. The expenses of preparing
      and filing such returns shall be borne by the Trustee.

     

    (e) The
      Trustee or its designee shall perform on behalf of each REMIC all reporting
      and
      other tax compliance duties that are the responsibility of such REMIC under
      the
      Code, the REMIC Provisions, or other compliance guidance issued by the Internal
      Revenue Service or any state or local taxing authority. Among its other duties,
      if required by the Code, the REMIC Provisions, or other such guidance, the
      Trustee shall provide (i) to the Treasury or other governmental authority such
      information as is necessary for the application of any tax relating to the
      transfer of a Residual Certificate to any disqualified person or organization
      pursuant to Treasury Regulation 1.860E-2(a)(5) and any person designated in
      Section 860E(e)(3) of the Code and (ii) to the Certificateholders such
      information or reports as are required by the Code or REMIC
      Provisions.

     

    The
      Trustee shall be entitled to receive reasonable compensation from the Trust
      Fund
      for the performance of its duties under this subsection (e); provided,
      however,
      that
      such compensation shall not exceed $5,000 per year; provided,
      further,
      that
      after a Section 7.01(c) Purchase Event, any expenses incurred by the Trustee
      in
      connection with such Section 7.01(c) Purchase Event shall be reimbursed to
      the
      Trustee, regardless of the limitation set forth above, in accordance with
      Section 4.04(b).

     

    (f) The
      Trustee, the Master Servicer and the Holders of Certificates shall take any
      action, within their respective control and scope of duties, or cause any REMIC
      to take any action necessary to create or maintain the status of any REMIC
      as a
      REMIC under the REMIC Provisions and shall assist each other as necessary to
      create or maintain such status. None of the Trustee, the Master Servicer or
      the
      Holder of any Residual Certificate shall knowingly take any action, within
      its
      respective control, cause any REMIC to take any action or fail to take (or
      fail
      to cause to be taken) any action within its respective control and scope of
      duties, that, under the REMIC Provisions, if taken or not taken, as the case
      may
      be, could result in an Adverse REMIC Event unless the Trustee and the Master
      Servicer have received an Opinion of Counsel addressed to the Trustee (at the
      expense of the party seeking to take such action) to the effect that the
      contemplated action will not result in an Adverse REMIC Event. In addition,
      prior to taking any action with respect to any REMIC or the assets therein,
      or
      causing any REMIC to take any action, which is not expressly permitted under
      the
      terms of this Agreement, any Holder of a Residual Certificate will consult
      with
      the Trustee, the Master Servicer or their respective designees, in writing,
      with
      respect to whether such action could cause an Adverse REMIC Event to occur
      with
      respect to any REMIC, and no such Person shall take any such action or cause
      any
      REMIC to take any such action as to which the Trustee or the Master Servicer
      has
      advised it in writing that an Adverse REMIC Event could occur.

     

    
      
        
        

      

      
        151

        
          

        

      

      
        
        

      

    

     

    (g) Each
      Holder of a Residual Certificate shall pay when due any and all taxes imposed
      on
      the related REMIC by federal or state governmental authorities. To the extent
      that such taxes are not paid by a Residual Certificateholder, the Trustee shall
      pay any remaining REMIC taxes out of current or future amounts otherwise
      distributable to the Holder of the Residual Certificate in any such REMIC or,
      if
      no such amounts are available, out of other amounts held in the Collection
      Account, and shall reduce amounts otherwise payable to holders of regular
      interests in any such REMIC, as the case may be.

     

    (h) The
      Trustee shall, for federal income tax purposes, maintain books and records
      with
      respect to each REMIC on a calendar year and on an accrual basis.

     

    (i) No
      additional contributions of assets shall be made to any REMIC, except as
      expressly provided in this Agreement.

     

    (j) Neither
      the Trustee nor the Master Servicer shall enter into any arrangement by which
      any REMIC will receive a fee or other compensation for services.

     

    (k) [Reserved]
      

     

    (l) The
      Trustee shall treat each of the Basis Risk Reserve Fund and the Supplemental
      Interest Trust as an outside reserve fund within the meaning of Treasury
      Regulation Section 1.860G-2(h) that is owned by the Holders of the Class X
      Certificates and that is not an asset of any REMIC and all amounts deposited
      into the Basis Risk Reserve Fund or the Supplemental Interest Trust shall be
      treated as amounts distributed to the Class X Certificateholders. 

     

    (m) [Reserved]

     

    (n) The
      Trustee shall treat the beneficial owners of Certificates (other than the
      Class P, Class X, Class LT-R and Class R Certificates) as having
      entered into a notional principal contract with respect to the beneficial owners
      of the Class X Certificates. Pursuant to each such notional principal contract,
      all beneficial owners of the Publicly Offered Certificates and the Class B1
      and
      Class B2 Certificates shall be treated as having agreed to pay, on each
      Distribution Date, to the beneficial owners of the Class X Certificates an
      aggregate amount equal to the excess, if any, of (i) the amount payable on
      such
      Distribution Date on the interest in the Upper Tier REMIC corresponding to
      such
      Class of Certificates over (ii) the amount payable on such Class of Certificates
      on such Distribution Date (such excess, a “Class I Shortfall”). A Class I
      Shortfall payable from interest collections shall be allocated to each Class
      of
      Certificates to the extent that interest accrued on such Class for the related
      Accrual Period at the Certificate Interest Rate for a Class, computed by
      substituting “REMIC 3 Net Funds Cap” for “Net Funds Cap” in the definition
      thereof, exceeds the amount of interest accrued for the related Accrual Period
      based on the Net Funds Cap, and a Class I Shortfall payable from principal
      collections shall be allocated to the most subordinate Class of Certificates
      with an outstanding principal balance to the extent of such balance. In
      addition, pursuant to such notional principal contract, the beneficial owner
      of
      the Class X Certificates shall be treated as having agreed to pay any interest
      to the extent it reflects an interest rate greater than the REMIC 3 Net
      Funds Cap, including any Basis Risk Shortfalls and Unpaid Basis Risk Shortfalls,
      to the Owners of the Publicly Offered Certificates and the Class B1 and Class
      B2
      Certificates in accordance with the terms of this Agreement. Any payments to
      the
      Certificates in light of the foregoing shall not be payments with respect to
      a
“regular interest” in a REMIC within the meaning of Code Section 860G(a)(1).
      However, any payment from the Certificates of a Class I Shortfall shall be
      treated for tax purposes as having been received by the beneficial owners of
      such Certificates in respect of their interests in the Upper Tier REMIC and
      as
      having been paid by such beneficial owners to the Supplemental Interest Trust
      pursuant to the notional principal contract. Thus, each Certificate (other
      than
      a Class P, Class R and Class LT-R Certificate) shall be treated as
      representing not only ownership of regular interests in the Upper Tier REMIC,
      but also ownership of an interest in (and obligations with respect to) a
      notional principal contract. For tax purposes, the notional principal contract
      shall be deemed to have a value in favor of the Certificates entitled to receive
      Basis Risk Shortfalls and Unpaid Basis Risk Shortfalls of $26,579.08 as of
      the
      Closing Date.

     

    
      
        
        

      

      
        152

        
          

        

      

      
        
        

      

    

     

    (o) Notwithstanding
      the priority and sources of payments set forth in Article V hereof or otherwise,
      the Trustee shall account for all distributions on the Certificates as set
      forth
      in this Section 10.01. In no event shall any interest to the extent it reflects
      an interest rate greater than the REMIC 3 Net Funds Cap, including any
      payments of Basis Risk Shortfalls or Unpaid Basis Risk Shortfalls, provided
      for
      in this Section 10.01 be treated as payments with respect to a “regular
      interest” in a REMIC within the meaning of Code Section 860G(a)(1).

     

    
      	 	
              Section
                10.02 

            	
              Prohibited
                Transactions andActivities. 

            


    

     

    Neither
      the Depositor, the Master Servicer nor the Trustee shall sell, dispose of,
      or
      substitute for any of the Mortgage Loans, except in a disposition pursuant
      to
      (i) the foreclosure of a Mortgage Loan, (ii) the bankruptcy of the Trust Fund,
      (iii) the termination of each REMIC pursuant to Article VII of this Agreement,
      (iv) a substitution pursuant to Article II of this Agreement or (v) a repurchase
      of Mortgage Loans pursuant to Article II of this Agreement, nor acquire any
      assets for any REMIC, nor sell or dispose of any investments in the Certificate
      Account for gain, nor accept any contributions to any REMIC after the Closing
      Date, unless the Trustee has received an Opinion of Counsel addressed to the
      Trustee (at the expense of the party causing such sale, disposition, or
      substitution) that such disposition, acquisition, substitution, or acceptance
      will not (a) result in an Adverse REMIC Event, (b) affect the distribution
      of
      interest or principal on the Certificates or (c) result in the encumbrance
      of
      the assets transferred or assigned to the Trust Fund (except pursuant to the
      provisions of this Agreement).

     

    
      
        
        

      

      
        153

        
          

        

      

      
        
        

      

    

     

    
      	 	
              Section
                10.03 

            	
              Indemnification
                with Respect to Certain Taxes and Loss of REMIC Status. 

            


    

     

    Upon
      the
      occurrence of an Adverse REMIC Event due to the negligent performance by the
      Trustee of its duties and obligations set forth herein, the Trustee shall
      indemnify the Holder of the related Residual Certificate or the Trust Fund,
      as
      applicable, against any and all losses, claims, damages, liabilities or expenses
      (“Losses”)
      resulting from such negligence; provided,
      however,
      that the
      Trustee shall not be liable for any such Losses attributable to the action
      or
      inaction of the Master Servicer, the Depositor, the Class X Certificateholders,
      or the Holder of such Residual Certificate, as applicable, nor for any such
      Losses resulting from misinformation provided by the Holder of such Residual
      Certificate on which the Trustee has relied. The foregoing shall not be deemed
      to limit or restrict the rights and remedies of the Holder of such Residual
      Certificate now or hereafter existing at law or in equity. Notwithstanding
      the
      foregoing, however, in no event shall the Trustee have any liability (1) for
      any
      action or omission that is taken in accordance with and in compliance with
      the
      express terms of, or which is expressly permitted by the terms of, this
      Agreement or the Servicing Agreement, (2) for any Losses other than arising
      out
      of a negligent performance by the Trustee of its duties and obligations set
      forth herein, and (3) for any special or consequential damages to
      Certificateholders (in addition to payment of principal and interest on the
      Certificates) even if the Trustee has been advised of the likelihood of such
      loss or damage and regardless of the form of action. In addition, the Trustee
      shall not have any liability for the actions or failure to act of any other
      party hereto.

     

    
      	 	
              Section
                10.04 

            	
              REO
                Property. 

            


    

     

    (a) Notwithstanding
      any other provision of this Agreement, the Master Servicer, acting on behalf
      of
      the Trustee hereunder, shall not, except to the extent provided in the Servicing
      Agreement, knowingly permit the Servicer to, rent, lease, or otherwise earn
      income on behalf of any REMIC with respect to any REO Property which might
      cause
      an Adverse REMIC Event unless the Master Servicer has advised, or has caused
      the
      Servicer to advise and the Trustee in writing to the effect that, under the
      REMIC Provisions, such action would not result in an Adverse REMIC
      Event.

     

    (b) The
      Master Servicer shall cause the Servicer (to the extent provided in its
      Servicing Agreement) to make reasonable efforts to sell any REO Property for
      its
      fair market value. In any event, however, the Master Servicer shall, or shall
      cause the Servicer (to the extent provided in its Servicing Agreement) to,
      dispose of any REO Property within three years of its acquisition by the Trust
      Fund unless the Master Servicer has received a grant of extension from the
      Internal Revenue Service to the effect that, under the REMIC Provisions, the
      REMIC may hold REO Property for a longer period without causing an Adverse
      REMIC
      Event. If the Master Servicer has received such an extension, then the Master
      Servicer, acting on the Trustee’s behalf hereunder, shall, or shall cause the
      Servicer to, continue to attempt to sell the REO Property for its fair market
      value for such period longer than three years as such extension permits (the
      “Extended Period”). If the Master Servicer has not received such an extension
      and the Master Servicer or the Servicer, acting on behalf of the Trustee
      hereunder, is unable to sell the REO Property within 33 months after its
      acquisition by the Trust Fund or if the Master Servicer has received such an
      extension, and the Master Servicer or the Servicer is unable to sell the REO
      Property within the period ending three months before the close of the Extended
      Period, the Master Servicer shall cause the Servicer, before the end of the
      three year period or the Extended Period, as applicable, to (i) purchase such
      REO Property at a price equal to the REO Property’s fair market value or (ii)
      auction the REO Property to the highest bidder (which may be the Servicer)
      in an
      auction reasonably designed to produce a fair price prior to the expiration
      of
      the three-year period or the Extended Period, as the case may be.

     

    
      
        
        

      

      
        154

        
          

        

      

      
        
        

      

    

     

    ARTICLE
      XI

     

    MISCELLANEOUS
      PROVISIONS

     

    
      	 	
              Section
                11.01 

            	
              Binding
                Nature of Agreement; Assignment. 

            


    

     

    This
      Agreement shall be binding upon and inure to the benefit of the parties hereto
      and their respective successors and permitted assigns.

     

    
      	 	
              Section
                11.02 

            	
              Entire
                Agreement. 

            


    

     

    This
      Agreement contains the entire agreement and understanding among the parties
      hereto with respect to the subject matter hereof, and supersedes all prior
      and
      contemporaneous agreements, understandings, inducements and conditions, express
      or implied, oral or written, of any nature whatsoever with respect to the
      subject matter hereof. The express terms hereof control and supersede any course
      of performance and/or usage of the trade inconsistent with any of the terms
      hereof.

     

    
      	 	
              Section
                11.03 

            	
              Amendment.  

            


    

     

    (a) On
      or
      prior to a Section 7.01(c) Purchase Event, this Agreement may be amended from
      time to time by the Depositor, the Master Servicer, and the Trustee, without
      the
      consent of the Credit Risk Manager or the Swap Counterparty (except to the
      extent that the rights or obligations of (1) the Credit Risk Manager or the
      Swap
      Counterparty hereunder or (2) the Swap Counterparty under the Swap Agreement
      are
      affected thereby, and except to the extent the ability of the Trustee on behalf
      of the Supplemental Interest Trust and the Trust Fund to perform fully and
      timely its obligations under the Swap Agreement is adversely affected, in which
      case prior written consent of the Swap Counterparty is required), and without
      notice to or the consent of any of the Holders, (i) to cure any ambiguity,
      (ii)
      to cause the provisions herein to conform to or be consistent with or in
      furtherance of the statements made with respect to the Certificates, the Trust
      Fund or this Agreement in any Offering Document, or to correct or supplement
      any
      provision herein which may be inconsistent with any other provisions herein
      or
      with the provisions of the Servicing Agreement, (iii) to make any other
      provisions with respect to matters or questions arising under this Agreement
      or
      (iv) to add, delete, or amend any provisions to the extent necessary or
      desirable to comply with any requirements imposed by the Code and the REMIC
      Provisions as evidenced by an Opinion of Counsel. No such amendment effected
      pursuant to the preceding sentence shall, as evidenced by an Opinion of Counsel,
      result in an Adverse REMIC Event, nor shall such amendment effected pursuant
      to
      clause (iii) of such sentence adversely affect in any material respect the
      interests of any Holder. Prior to entering into any amendment without the
      consent of Holders pursuant to this paragraph, the Trustee and the Swap
      Counterparty shall be provided with an Opinion of Counsel addressed to the
      Trustee and the Swap Counterparty (at the expense of the party requesting such
      amendment) to the effect that such amendment is permitted under this Section.
      Any such amendment shall be deemed not to adversely affect in any material
      respect any Holder, if the Trustee receives prior written confirmation from
      each
      Rating Agency that such amendment will not cause such Rating Agency to reduce
      the then current rating assigned to the Certificates.

     

    
      
        
        

      

      
        155

        
          

        

      

      
        
        

      

    

     

    (b) On
      or
      prior to a Section 7.01(c) Purchase Event, this Agreement may also be
      amended from time to time by the Depositor, the Master Servicer and the Trustee,
      without the consent of the Credit Risk Manager or the Swap Counterparty (except
      to the extent that the rights or obligations of (1) the Credit Risk Manager
      or
      the Swap Counterparty hereunder or (2) the Swap Counterparty under the Swap
      Agreement are affected thereby or the ability of the Trustee on behalf of the
      Supplemental Interest Trust and the Trust Fund to perform fully and timely
      its
      obligations under the Swap Agreement is adversely affected, in which case prior
      written consent of the Swap Counterparty is required) and with the consent
      of
      the Holders of not less than 66-2/3% of the Class Principal Amount (or
      Percentage Interest) of each Class of Certificates affected thereby for the
      purpose of adding any provisions to or changing in any manner or eliminating
      any
      of the provisions of this Agreement or of modifying in any manner the rights
      of
      the Holders; provided,
      however,
      that no
      such amendment shall be made unless the Trustee receives an Opinion of Counsel
      addressed to the Trustee, at the expense of the party requesting the change,
      that such change will not cause an Adverse REMIC Event; and provided,
      further,
      that no
      such amendment may (i) reduce in any manner the amount of, or delay the timing
      of, payments received on Mortgage Loans which are required to be distributed
      on
      any Certificate, without the consent of the Holder of such Certificate or (ii)
      reduce the aforesaid percentages of Class Principal Amount (or Percentage
      Interest) of Certificates of each Class, the Holders of which are required
      to
      consent to any such amendment without the consent of the Holders of 100% of
      the
      Class Principal Amount (or Percentage Interest) of each Class of Certificates
      affected thereby. For purposes of this paragraph, references to “Holder” or
“Holders” shall be deemed to include, in the case of any Class of Book-Entry
      Certificates, the related Certificate Owners.

     

    (c) After
      a
      Section 7.01(c) Purchase Event but on or prior to a Trust Fund Termination
      Event, this Agreement may be amended from time to time by the Depositor, the
      Master Servicer, the LTURI-holder and the Trustee, but without the consent
      of
      the Credit Risk Manager or the Swap Counterparty (except to the extent that
      the
      rights or obligations of (1) the Credit Risk Manager or the Swap Counterparty
      or
      (2) the Swap Counterparty under the Swap Agreement or the ability of the Trustee
      on behalf of the Supplemental Interest Trust and the Trust Fund to perform
      fully
      and timely its obligations under the Swap Agreement is adversely affected,
      in
      which case prior written consent of the Credit Risk Manager or the Swap
      Counterparty, as applicable, is required). Prior to entering into any amendment
      without the consent of Holders pursuant to this paragraph, the Trustee and
      the
      Swap Counterparty shall be provided with an Opinion of Counsel addressed to
      the
      Trustee and the Swap Counterparty (at the expense of the party requesting such
      amendment) to the effect that such amendment is permitted under this Section
      and
      will not result in an Adverse REMIC Event.

     

    (d) Promptly
      after the execution of any such amendment, the Trustee shall furnish written
      notification of the substance of such amendment to each Holder, the Depositor,
      the Swap Counterparty and the Rating Agencies.

     

    
      
        
        

      

      
        156

        
          

        

      

      
        
        

      

    

     

    (e) It
      shall
      not be necessary for the consent of Holders under this Section 11.03 to approve
      the particular form of any proposed amendment, but it shall be sufficient if
      such consent shall approve the substance thereof. The manner of obtaining such
      consents and of evidencing the authorization of the execution thereof by Holders
      shall be subject to such reasonable regulations as the Trustee may
      prescribe.

     

    (f) Notwithstanding
      anything to the contrary in the Servicing Agreement, the Trustee shall not
      consent to any amendment of the Servicing Agreement unless (i) such amendment
      is
      effected pursuant to the standards provided in Section 11.03(a) or Section
      11.03(b) with respect to amendment of this Agreement and (ii) except for a
      Permitted Servicing Amendment, any such amendment pursuant to Section
      11.03(a)(iii) shall not be materially inconsistent with the provisions of such
      Servicing Agreement.

     

    (g) Notwithstanding
      anything to the contrary in this Section 11.03, this Agreement may be amended
      from time to time by the Depositor, the Master Servicer and the Trustee to
      the
      extent necessary, in the judgment of the Depositor and its counsel, to comply
      with the Rules.

     

    
      	 	
              Section
                11.04 

            	
              Voting
                Rights. 

            


    

     

    Except
      to
      the extent that the consent of all affected Certificateholders is required
      pursuant to this Agreement, with respect to any provision of this Agreement
      requiring the consent of Certificateholders representing specified percentages
      of aggregate outstanding Certificate Principal Amount (or Percentage Interest),
      Certificates owned by the Depositor, the Master Servicer, the Trustee, the
      Servicer, the Credit Risk Manager or Affiliates thereof are not to be counted
      so
      long as such Certificates are owned by the Depositor, the Master Servicer,
      the
      Trustee, the Servicer, the Credit Risk Manager or any Affiliate
      thereof.

     

    
      	 	
              Section
                11.05 

            	
              Provision
                of Information. 

            


    

     

    (a) For
      so
      long as any of the Certificates of any Series or Class are “restricted
      securities” within the meaning of Rule 144(a)(3) under the Act, each of the
      Depositor, the Master Servicer and the Trustee agree to cooperate with each
      other to provide to any Certificateholders, and to any prospective purchaser
      of
      Certificates designated by such holder, upon the request of such holder or
      prospective purchaser, any information required to be provided to such holder
      or
      prospective purchaser to satisfy the condition set forth in Rule 144A(d)(4).
      Any
      reasonable, out-of-pocket expenses incurred by the Master Servicer or the
      Trustee in providing such information shall be reimbursed by the
      Depositor.

     

    (b) The
      Trustee shall make available to any person to whom a Prospectus was delivered,
      upon the request of such person specifying the document or documents requested,
      (i) a copy (excluding exhibits) of any report on Form 8-K, Form 10-D or Form
      10-K filed with the Commission pursuant to Section 6.20(c) and (ii) a copy
      of
      any other document incorporated by reference in the Prospectus (to the extent
      that the Trustee has such documents in its possession or such documents are
      reasonably obtainable by the Trustee). Any reasonable out-of-pocket expenses
      incurred by the Trustee in providing copies of such documents shall be
      reimbursed by the Depositor.

     

    
      
        
        

      

      
        157

        
          

        

      

      
        
        

      

    

     

    (c) On
      each
      Distribution Date, the Trustee shall make available on its website to the
      Depositor a copy of the report delivered to Certificateholders pursuant to
      Section 4.03.

     

    
      	 	
              Section
                11.06 

            	
              Governing
                Law. 

            


    

     

    THIS
      AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF
      THE
      STATE OF NEW YORK, WITHOUT REFERENCE TO ITS CONFLICT OF LAW PROVISIONS (OTHER
      THAN SECTION 5-1401 OF THE GENERAL OBLIGATIONS LAW), AND THE OBLIGATIONS, RIGHTS
      AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN ACCORDANCE WITH
      SUCH LAWS.

     

    
      	 	
              Section
                11.07 

            	
              Notices. 

            


    

     

    All
      demands, notices and communications hereunder shall be in writing and shall
      be
      deemed to have been duly given when received by (a) in the case of the
      Depositor, Structured Asset Securities Corporation, 745 Seventh Avenue, 7th
      Floor, New York, New York 10019, Attention:
      Mortgage Finance SASCO 2006-S4, (b) in the case of the Seller, Lehman
      Brothers Holdings Inc., 745 Seventh Avenue, 7th Floor, New York, New York 10019,
      Attention: Mortgage Finance SASCO 2006-S4, (c) in the case of the Trustee,
      Citibank, N.A., to the applicable Corporate Trust Office, (d) in the case
      of the Master Servicer, Aurora Loan Services LLC, 327 Inverness Drive South,
      Mail Stop 3195, Englewood, CO 80112; Attention: Master Servicing, SASCO 2006-S4,
      (e) in the case of the Credit Risk Manager, Clayton Fixed Income Services Inc.,
      1700 Lincoln Street, Suite 1600, Denver, Colorado 80203, Attention: General
      Counsel and (f) in the case of the Swap Counterparty, at the address therefore
      set forth in the Swap Agreement, or, as to each party, such other address as
      may
      hereafter be furnished by such party to the other parties in writing. All
      demands, notices and communications to a party hereunder shall be in writing
      and
      shall be deemed to have been duly given when delivered to such party at the
      relevant address, facsimile number or electronic mail address set forth above
      or
      at such other address, facsimile number or electronic mail address as such
      party
      may designate from time to time by written notice in accordance with this
      Section 11.07.

     

    
      	 	
              Section
                11.08 

            	
              Severability
                of Provisions. 

            


    

     

    If
      any
      one or more of the covenants, agreements, provisions or terms of this Agreement
      shall be for any reason whatsoever held invalid, then such covenants,
      agreements, provisions or terms shall be deemed severable from the remaining
      covenants, agreements, provisions or terms of this Agreement and shall in no
      way
      affect the validity or enforceability of the other provisions of this Agreement
      or of the Certificates or the rights of the Holders thereof.

     

    
      	 	
              Section
                11.09 

            	
              Indulgences;
                No Waivers. 

            


    

     

    Neither
      the failure nor any delay on the part of a party to exercise any right, remedy,
      power or privilege under this Agreement shall operate as a waiver thereof,
      nor
      shall any single or partial exercise of any right, remedy, power or privilege
      preclude any other or further exercise of the same or of any other right,
      remedy, power or privilege, nor shall any waiver of any right, remedy, power
      or
      privilege with respect to any occurrence be construed as a waiver of such right,
      remedy, power or privilege with respect to any other occurrence. No waiver
      shall
      be effective unless it is in writing and is signed by the party asserted to
      have
      granted such waiver.

     

    
      
        
        

      

      
        158

        
          

        

      

      
        
        

      

    

     

    
      	 	
              Section
                11.10 

            	
              Headings
                Not To Affect Interpretation. 

            


    

     

    The
      headings contained in this Agreement are for convenience of reference only,
      and
      they shall not be used in the interpretation hereof.

     

    
      	 	
              Section
                11.11 

            	
              [Reserved].

            


    

     

    
      	 	
              Section
                11.12 

            	
              Special
                Notices to the Rating Agencies.  

            


    

     

    (a) The
      Depositor shall give prompt notice to the Rating Agencies of the occurrence
      of
      any of the following events of which it has notice:

     

    (i) any
      amendment to this Agreement pursuant to Section 11.03;

     

    (ii) any
      Assignment by the Master Servicer of its rights hereunder or delegation of
      its
      duties hereunder;

     

    (iii) the
      occurrence of any Event of Default described in Section 6.14;

     

    (iv) any
      notice of termination given to the Master Servicer pursuant to Section 6.14
      and
      any resignation of the Master Servicer hereunder;

     

    (v) the
      appointment of any successor to any Master Servicer pursuant to Section 6.14;
      

     

    (vi) the
      making of a final payment pursuant to Section 7.02; and

     

    (vii) any
      termination of the rights and obligations of the Servicer under the Servicing
      Agreement.

     

    (b) All
      notices to the Rating Agencies provided for in this Section shall be in writing
      and sent by first class mail, telecopy or overnight courier, as
      follows:

     

    If
      to
      S&P, to:

    


    Standard
      & Poor’s Ratings Services,

    a
      division of The McGraw-Hill Companies, Inc. 

    55
      Water
      Street

    New
      York,
      New York 10041

    Attention:
      Residential Mortgages

    


    If
      to
      Moody’s,
      to:

    


    Moody’s
      Investors Service, Inc.

    99
      Church
      Street 

    New
      York,
      New York 10007

    Attention:
      Residential Mortgages

     

    
      
        
        

      

      
        159

        
          

        

      

      
        
        

      

    

     

    (c) The
      Trustee shall provide or make available to the Rating Agencies reports prepared
      pursuant to Section 4.03. In addition, the Trustee shall, at the expense of
      the
      Trust Fund, make available to each Rating Agency such information as such Rating
      Agency may reasonably request regarding the Certificates or the Trust Fund,
      to
      the extent that such information is reasonably available to the
      Trustee.

     

    
      	 	
              Section
                11.13 

            	
              Conflicts. 

            


    

     

    To
      the
      extent that the terms of this Agreement conflict with the terms of the Servicing
      Agreement, the Servicing Agreement shall govern unless such provisions shall
      adversely affect the Trustee or the Trust Fund.

     

    
      	 	
              Section
                11.14 

            	
              Counterparts. 

            


    

     

    This
      Agreement may be executed in one or more counterparts, each of which shall
      be
      deemed to be an original, and all of which together shall constitute one and
      the
      same instrument.

     

    
      	 	
              Section
                11.15 

            	
              Transfer
                of Servicing. 

            


    

     

    The
      Seller agrees that it shall provide written notice to the Master Servicer,
      the
      Swap Counterparty and the Trustee thirty days prior to any proposed transfer
      or
      assignment by such Seller of its rights under the Servicing Agreement or of
      the
      servicing thereunder or delegation of its rights or duties thereunder or any
      portion thereof to any other Person other than the initial Servicer under
the
      Servicing Agreement. In addition, the ability of the Seller to transfer or
      assign its rights and delegate its duties under the Servicing Agreement or
      to
      transfer the servicing thereunder to a successor servicer shall be subject
      to
      the following conditions:

     

    (i) Satisfaction
      of the conditions to such transfer as set forth in the Servicing Agreement
      including, without limitation, receipt of written consent of the Master Servicer
      to such transfer;

     

    (ii) Such
      successor servicer must be qualified to service loans for Freddie Mac, and
      must
      be a member in good standing of MERS;

     

    (iii) Such
      successor servicer must satisfy the seller/servicer eligibility standards in
      the
      Servicing Agreement, exclusive of any experience in mortgage loan
      origination;

     

    (iv) Such
      successor servicer must execute and deliver to the Trustee and the Master
      Servicer an agreement, in form and substance reasonably satisfactory to the
      Trustee and the Master Servicer, that contains an assumption by such successor
      servicer of the due and punctual performance and observance of each covenant
      and
      condition to be performed and observed by the Servicer under the Servicing
      Agreement or, in the case of a transfer of servicing to a party that is already
      the Servicer pursuant to this Agreement, an agreement to add the related
      Mortgage Loans to the Servicing Agreement already in effect for such
      Servicer;

     

    
      
        
        

      

      
        160

        
          

        

      

      
        
        

      

    

     

    (v) There
      must be delivered to the Trustee and the Master Servicer a letter from each
      Rating Agency to the effect that such transfer of servicing will not result
      in a
      qualification, withdrawal or downgrade of the then-current rating of any of
      the
      Certificates; and

     

    (vi) The
      Seller shall, at its cost and expense, take such steps, or cause the terminated
      Servicer to take such steps, as may be necessary or appropriate to effectuate
      and evidence the transfer of the servicing of the Mortgage Loans to such
      successor servicer, including, but not limited to, the following: (A) to the
      extent required by the terms of the Mortgage Loans and by applicable federal
      and
      state laws and regulations, the Seller shall cause the prior Servicer to timely
      mail to each obligor under a Mortgage Loan any required notices or disclosures
      describing the transfer of servicing of the Mortgage Loans to the successor
      servicer; (B) prior to the effective date of such transfer of servicing, the
      Seller shall cause the prior Servicer to transmit to any related insurer
      notification of such transfer of servicing; (C) on or prior to the effective
      date of such transfer of servicing, the Seller shall cause the prior Servicer
      to
      deliver to the successor servicer all Mortgage Loan Documents and any related
      records or materials; (D) on or prior to the effective date of such transfer
      of
      servicing, the Seller shall cause the prior Servicer to transfer to the
      successor servicer, or, if such transfer occurs after the Servicer Remittance
      Date but before the next succeeding Master Servicer Remittance Date, to the
      Trustee, all funds held by the prior Servicer in respect of the Mortgage Loans;
      (E) on or prior to the effective date of such transfer of servicing, the Seller
      shall cause the prior Servicer to, after the effective date of the transfer
      of
      servicing to the successor servicer, continue to forward to such successor
      servicer, within one Business Day of receipt, the amount of any payments or
      other recoveries received by the prior Servicer, and to notify the successor
      servicer of the source and proper application of each such payment or recovery;
      and (F) the Seller shall cause the prior Servicer to, after the effective date
      of transfer of servicing to the successor servicer, continue to cooperate with
      the successor servicer to facilitate such transfer in such manner and to such
      extent as the successor servicer may reasonably request. Notwithstanding the
      foregoing, the prior Servicer shall be obligated to perform the items listed
      above to the extent provided in the Servicing Agreement.

     

    


    [Signature
      page to follow]

     

    
      
        
        

      

      
        161

        
          

        

      

      
        
        

      

    

    


    IN
      WITNESS WHEREOF, the parties hereto have caused their names to be signed hereto
      by their respective officers hereunto duly authorized as of the day and year
      first above written.

     

    
      	 	 	 
	 	
              STRUCTURED
                ASSET SECURITIES

              CORPORATION,
                as Depositor

            
	 
 	 
 	 
 
	 	By:  	/s/ Ellen
              V.
              Kiernan
	 	
              
Name:
              Ellen V. Kiernan
	 	Title:
              Senior Vice President


    

    
       

      
        	 	 	 
	 	
                AURORA
                  LOAN SERVICES LLC, as Master Servicer

              
	 
 	 
 	 
 
	 	By:  	/s/ Jerald
                W.
                Dreyer
	 	
                
Name:
                Jerald W. Dreyer
	 	Title:
                Vice President


      

    

    
      
         

        
          	 	 	 
	 	
                  CITIBANK,
                    N.A., as Trustee

                
	 
 	 
 	 
 
	 	By:  	/s/ Karen
                  Schluter
	 	
                  
Name:
                  Karen Schluter
	 	Title:
                  Vice President


        

      

      
        
          
             

            
              	 	 	 
	 	
                      CLAYTON
                        FIXED INCOME SERVICES INC.,
as
                        Credit Risk Manager

                    
	 
 	 
 	 
 
	 	By:  	/s/ Kevin
                      J.
                      Kanouff
	 	
                      
Name:
                      Kevin J. Kanouff
	 	Title:
                      President and General Counsel


            

          

           

        

      

    

    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

    

    


    Solely
      for purposes of Sections 5.07(a), 5.07(f),
      6.11 and 11.15, 

    accepted
      and agreed to by:

     

    LEHMAN
      BROTHERS HOLDINGS INC.

     

    By: /s/
      Michael C. Hitzmann 

    Name:
      Michael C. Hitzmann

    Title:
      Authorized Signatory 

    


    
      
        
        

      

      
        
        

        
          

        

      

      
        
        

      

       

    

    EXHIBIT
      A-1

    


    [FORM
      OF
      SENIOR CERTIFICATE]

    


    SOLELY
      FOR U.S. FEDERAL INCOME TAX PURPOSES, THIS CERTIFICATE REPRESENTS OWNERSHIP
      OF A
“REGULAR INTEREST” IN A “REAL ESTATE MORTGAGE INVESTMENT CONDUIT,” AS THOSE
      TERMS ARE DEFINED, RESPECTIVELY, IN SECTIONS 860G AND 860D OF THE INTERNAL
      REVENUE CODE OF 1986, AS AMENDED (THE “CODE”), AND A RIGHT TO RECEIVE PAYMENTS
      FROM THE BASIS RISK RESERVE FUND.

     

    THIS
      CERTIFICATE DOES NOT EVIDENCE AN OBLIGATION OF, OR AN INTEREST IN, AND IS NOT
      GUARANTEED BY, THE DEPOSITOR, THE TRUSTEE, THE MASTER SERVICER OR ANY AFFILIATE
      OF ANY OF THEM AND IS NOT INSURED OR GUARANTEED BY ANY GOVERNMENTAL AGENCY
      OR
      PRIVATE INSURER.

     

    DISTRIBUTIONS
      IN REDUCTION OF THE CERTIFICATE PRINCIPAL AMOUNT OF THIS CERTIFICATE MAY BE
      MADE
      IN INSTALLMENTS AS SET FORTH HEREIN. ACCORDINGLY, THE CERTIFICATE PRINCIPAL
      AMOUNT OF THIS CERTIFICATE AT ANY TIME MAY BE LESS THAN THE INITIAL CERTIFICATE
      PRINCIPAL AMOUNT OF THIS CERTIFICATE AS SET FORTH HEREIN.

     

    UNLESS
      THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY
      TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO THE ISSUER OR ITS AGENT FOR
      REGISTRATION OF TRANSFER, EXCHANGE, OR PAYMENT, AND ANY CERTIFICATE ISSUED
      IS
      REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED
      BY AN AUTHORIZED REPRESENTATIVE OF DTC AND ANY PAYMENT IS MADE TO CEDE & CO.
      OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF
      DTC,
      ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
      PERSON IS WRONGFUL, INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS
      AN INTEREST HEREIN.

     

    
      
         

      

      
        A-1-1

        
          

        

      

      
         

      

    

     

    NO
      TRANSFER OF THIS CERTIFICATE PRIOR TO THE TERMINATION OF THE SWAP AGREEMENT
      SHALL BE MADE UNLESS THE TRUSTEE SHALL HAVE RECEIVED A REPRESENTATION LETTER
      FROM THE TRANSFEREE OF THIS CERTIFICATE TO THE EFFECT THAT EITHER (I) SUCH
      TRANSFEREE IS NEITHER AN EMPLOYEE BENEFIT PLAN OR OTHER RETIREMENT ARRANGEMENT
      WHICH IS SUBJECT TO SECTION 406 OF ERISA AND/OR SECTION 4975 OF THE CODE OR
      ANY
      ENTITY WHOSE UNDERLYING ASSETS INCLUDE SUCH PLAN’S OR ARRANGEMENT’S ASSETS BY
      REASON OF THEIR INVESTMENT IN THE ENTITY (A “PLAN”) NOR A PERSON ACTING ON
      BEHALF OF ANY SUCH PLAN OR USING THE ASSETS OF ANY SUCH PLAN TO EFFECT SUCH
      TRANSFER OR (II) THE ACQUISITION AND HOLDING OF THIS CERTIFICATE ARE ELIGIBLE
      FOR EXEMPTIVE RELIEF UNDER PROHIBITED TRANSACTION CLASS EXEMPTION (“PTCE”)
      84-14, PTCE 90-1, PTCE 91-38, PTCE 95-60 OR PTCE 96-23. ANY PURPORTED TRANSFER
      OF THIS CERTIFICATE PRIOR TO THE TERMINATION OF THE SWAP AGREEMENT TO OR ON
      BEHALF OF A PLAN WITHOUT THE DELIVERY TO THE TRUSTEE OF A REPRESENTATION LETTER
      AS DESCRIBED ABOVE SHALL BE VOID AND OF NO EFFECT. IF THIS CERTIFICATE IS A
      BOOK-ENTRY CERTIFICATE PRIOR TO THE DATE OF THE TERMINATION OF THE SWAP
      AGREEMENT, THE TRANSFEREE WILL BE DEEMED TO HAVE MADE A REPRESENTATION AS
      PROVIDED IN CLAUSE (I) OR (II) OF THIS PARAGRAPH, AS APPLICABLE.

     

    


    
      
        
          
          

        

        
          A-1-2

          
            

          

        

        
          
          

        

      

    

    


    STRUCTURED
      ASSET SECURITIES CORPORATION, SERIES 2006-S4

    MORTGAGE
      PASS-THROUGH CERTIFICATE, CLASS A

     

    Evidencing
      a beneficial interest in a pool consisting primarily of certain conventional,
      second lien, fixed rate, fully amortizing and balloon, residential mortgage
      loans and other assets in a trust fund established by: 

     

    STRUCTURED
      ASSET SECURITIES CORPORATION

     

    

      
        	
                Initial
                  Class Principal

              	 	
                Initial
                  Certificate

              
	
                Amount
                  of the Class A

              	 	
                Principal
                  Amount of this

              
	
                Certificates:
                  $367,586,000

              	 	
                Certificate:
                  $367,586,000

              
	 	 	 
	
                Certificate
                  

              	 	
                Cut-off
                  Date: December 1, 2006

              
	
                Interest
                  Rate: Variable* 

                 

              	 	 
	
                NUMBER
                  1

              	 	
                CUSIP:
                  86363A AA 5

              


      

      

        
          
            

          

          *
            Subject
            to the Net Funds Cap, as provided in the Trust Agreement.

           

          
            
              
              

            

            
              A-1-3

              
                

              

            

            
              
              

            

             

          

        

      

    

    THIS
      CERTIFIES THAT CEDE & CO. is the registered owner of the Percentage Interest
      evidenced by this Certificate (obtained by dividing the Initial Certificate
      Principal Amount of this Certificate by the Initial Class Principal Amount
      of
      the Class A Certificates, both as specified above) evidencing beneficial
      ownership in a Trust Fund consisting primarily of (i) a pool of certain
      conventional, second lien, fixed rate, fully amortizing and balloon, residential
      mortgage loans acquired by the Trust Fund on the Closing Date (the “Mortgage
      Loans”), together with all collections therefrom and proceeds thereof (excluding
      all scheduled payments of principal and interest due on the Mortgage Loans
      on or
      before the Cut-off Date), (ii) any REO Property, together with all collections
      thereon and proceeds thereof, (iii) the Depositor’s rights under the Mortgage
      Loan Sale Agreement and the Servicing Agreement (including any security interest
      created thereby), (iv) the Depositor’s rights under any insurance policies
      related to the Mortgage Loans, (v) amounts on deposit from time to time in
      the Collection Account, the Certificate Account and the Basis Risk Reserve
      Fund
      and (vi) the Supplemental Interest Trust, the primary assets of which are the
      Swap Agreement and all proceeds thereof.

     

    Distributions
      on this Certificate will be made on the 25th day of each month or, if such
      day
      is not a Business Day, then on the next succeeding Business Day, commencing
      in
      January 2007 (each, a “Distribution Date”), to the Person in whose name this
      Certificate is registered at the close of business on the Business Day
      immediately preceding such Distribution Date, so long as such Certificate is
      in
      book-entry form (the “Record Date”), in an amount equal to the product of the
      Percentage Interest evidenced by this Certificate and the amount, if any,
      required to be distributed to all the Certificates of the Class represented
      by
      this Certificate. All sums distributable on this Certificate are payable in
      the
      coin or currency of the United States of America which at the time of payment
      is
      legal tender for the payment of public and private debts.

     

    Reference
      is hereby made to the further provisions of this Certificate set forth on the
      reverse hereof, which shall have the same effect as though fully set forth
      on
      the face of this Certificate.

     

    Unless
      the certificate of authentication hereon has been executed by or on behalf
      of
      the Trustee, whose name appears below by manual signature, this Certificate
      shall not be entitled to any benefit under the Trust Agreement or be valid
      for
      any purpose.

     

    
      
        
        

      

      
        A-1-4

        
          

        

      

      
        
        

      

    

    


    IN
      WITNESS WHEREOF, the Trustee has caused this Certificate to be duly
      executed.

     

    
      	 	 	 
	 	CITIBANK,
              N.A., as
              Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
              
AUTHORIZED
              SIGNATORY
	 	
               

              Dated:
                December _____, 2006

            


    

     

    TRUSTEE’S
      CERTIFICATE OF AUTHENTICATION

     

    This
      is
      one of the Certificates referred to in the within-mentioned Trust
      Agreement.

    
       

      
        	 	 	 
	 	CITIBANK,
                N.A., as
                Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                
AUTHORIZED
                SIGNATORY
	 	
                 

                Dated:
                  December _____, 2006

              


      

       

      
        
          
          

        

        
          A-1-5

          
            

          

        

        
          
          

        

      

    

     

    EXHIBIT
      A-2

    


    [FORM
      OF
      CLASS M CERTIFICATE]

    


     

    SOLELY
      FOR U.S. FEDERAL INCOME TAX PURPOSES, THIS CERTIFICATE REPRESENTS OWNERSHIP
      OF A
“REGULAR INTEREST” IN A “REAL ESTATE MORTGAGE INVESTMENT CONDUIT,” AS THOSE
      TERMS ARE DEFINED, RESPECTIVELY, IN SECTIONS 860G AND 860D OF THE INTERNAL
      REVENUE CODE OF 1986, AS AMENDED (THE “CODE”), AND A RIGHT TO RECEIVE PAYMENTS
      FROM THE BASIS RISK RESERVE FUND.

     

    THIS
      CERTIFICATE DOES NOT EVIDENCE AN OBLIGATION OF, OR AN INTEREST IN, AND IS NOT
      GUARANTEED BY, THE DEPOSITOR, THE TRUSTEE, THE MASTER SERVICER OR ANY AFFILIATE
      OF ANY OF THEM AND IS NOT INSURED OR GUARANTEED BY ANY GOVERNMENTAL AGENCY
      OR
      PRIVATE INSURER.

     

    DISTRIBUTIONS
      IN REDUCTION OF THE CERTIFICATE PRINCIPAL AMOUNT OF THIS CERTIFICATE MAY BE
      MADE
      IN INSTALLMENTS AS SET FORTH HEREIN. ACCORDINGLY, THE CERTIFICATE PRINCIPAL
      AMOUNT OF THIS CERTIFICATE AT ANY TIME MAY BE LESS THAN THE INITIAL CERTIFICATE
      PRINCIPAL AMOUNT OF THIS CERTIFICATE AS SET FORTH HEREIN.

     

    THIS
      CERTIFICATE IS SUBORDINATE IN RIGHT OF PAYMENT AS DESCRIBED IN THE TRUST
      AGREEMENT REFERRED TO HEREIN.

     

    UNLESS
      THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY
      TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO THE ISSUER OR ITS AGENT FOR
      REGISTRATION OF TRANSFER, EXCHANGE, OR PAYMENT, AND ANY CERTIFICATE ISSUED
      IS
      REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED
      BY AN AUTHORIZED REPRESENTATIVE OF DTC AND ANY PAYMENT IS MADE TO CEDE & CO.
      OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF
      DTC,
      ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
      PERSON IS WRONGFUL, INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS
      AN INTEREST HEREIN.

     

    NO
      TRANSFER OF THIS CERTIFICATE SHALL BE REGISTERED IF ITS RATING IS BELOW
      INVESTMENT GRADE UPON ACQUISITION UNLESS THE PROSPECTIVE TRANSFEREE PROVIDES
      THE
      TRUSTEE WITH (A) A CERTIFICATION TO THE EFFECT THAT SUCH TRANSFEREE (1) IS
      NEITHER AN EMPLOYEE BENEFIT PLAN OR OTHER RETIREMENT ARRANGEMENT SUBJECT TO
      SECTION 406 OF THE EMPLOYEE RETIREMENT INCOME SECURITY ACT OF 1974, AS AMENDED
      (“ERISA”), OR SECTION 4975 OF THE INTERNAL REVENUE CODE OF 1986, AS AMENDED (THE
“CODE”) (COLLECTIVELY, A “PLAN”), NOR A PERSON ACTING ON BEHALF OF ANY SUCH PLAN
      NOR A PERSON USING THE ASSETS OF ANY SUCH PLAN OR (2) IF SUCH TRANSFEREE IS
      AN
      INSURANCE COMPANY, SUCH TRANSFEREE IS PURCHASING SUCH CERTIFICATES WITH FUNDS
      CONTAINED IN AN “INSURANCE COMPANY GENERAL ACCOUNT” (AS SUCH TERM IS DEFINED IN
      SECTION V(e) OF THE PROHIBITED TRANSACTION CLASS EXEMPTION 95-60 (“PTCE 95-60”))
      AND THE PURCHASE AND HOLDING OF SUCH CERTIFICATES ARE COVERED UNDER SECTIONS
      I
      AND III OF PTCE 95-60; OR (B) AN OPINION OF COUNSEL SATISFACTORY TO THE TRUSTEE,
      AND UPON WHICH THE TRUSTEE, THE MASTER SERVICER AND THE DEPOSITOR SHALL BE
      ENTITLED TO RELY, TO THE EFFECT THAT THE PURCHASE OR HOLDING OF SUCH CERTIFICATE
      BY THE PROSPECTIVE TRANSFEREE WILL NOT RESULT IN ANY NON-EXEMPT PROHIBITED
      TRANSACTIONS UNDER TITLE I OF ERISA OR SECTION 4975 OF THE CODE AND WILL NOT
      SUBJECT THE TRUSTEE, THE MASTER SERVICER OR THE DEPOSITOR TO ANY OBLIGATION
      IN
      ADDITION TO THOSE UNDERTAKEN BY SUCH ENTITIES IN THE TRUST AGREEMENT, WHICH
      OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE TRUST FUND, THE TRUSTEE,
      THE
      MASTER SERVICER OR THE DEPOSITOR. A TRANSFEREE OF A BOOK-ENTRY CERTIFICATE
      SHALL
      BE DEEMED TO HAVE MADE A REPRESENTATION AS REQUIRED HEREIN.

     

    
      
        
        

      

      
        A-2-1

        
          

        

      

      
        
        

      

    

     

    NO
      TRANSFER OF THIS CERTIFICATE PRIOR
      TO
      THE TERMINATION OF THE SWAP AGREEMENT SHALL
      BE
      MADE UNLESS THE TRUSTEE SHALL HAVE RECEIVED A REPRESENTATION LETTER FROM THE
      TRANSFEREE OF THIS CERTIFICATE TO THE EFFECT THAT EITHER (I) SUCH TRANSFEREE
      IS
      NEITHER A PLAN NOR A PERSON ACTING ON BEHALF OF ANY SUCH PLAN OR USING THE
      ASSETS OF ANY SUCH PLAN TO EFFECT SUCH TRANSFER OR (II) THE ACQUISITION AND
      HOLDING OF THIS CERTIFICATE ARE ELIGIBLE FOR EXEMPTIVE RELIEF UNDER PROHIBITED
      TRANSACTION CLASS EXEMPTION PTCE 84-14, PTCE 90-1, PTCE 91-38, PTCE 95-60 OR
      PTCE 96-23. ANY PURPORTED TRANSFER OF THIS CERTIFICATE PRIOR TO THE TERMINATION
      OF THE SWAP AGREEMENT TO OR ON BEHALF OF A PLAN WITHOUT THE DELIVERY TO THE
      TRUSTEE OF A REPRESENTATION LETTER AS DESCRIBED ABOVE SHALL BE VOID AND OF
      NO
      EFFECT. IF THIS CERTIFICATE IS A BOOK-ENTRY CERTIFICATE PRIOR TO THE TERMINATION
      OF THE SWAP AGREEMENT, THE TRANSFEREE WILL BE DEEMED TO HAVE MADE A
      REPRESENTATION AS PROVIDED IN CLAUSE (I) OR (II) OF THIS PARAGRAPH, AS
      APPLICABLE.

     

    
      
        
        

      

      
        A-2-2

        
          

        

      

      
        
        

      

    

    


    STRUCTURED
      ASSET SECURITIES CORPORATION, SERIES 2006-S4

    MORTGAGE
      PASS-THROUGH CERTIFICATE, CLASS M[__]

     

    Evidencing
      a beneficial interest in a pool consisting primarily of certain conventional,
      second lien, fixed rate, fully amortizing and balloon, residential mortgage
      loans and other assets in a trust fund established by:

     

    STRUCTURED
      ASSET SECURITIES CORPORATION

     

    

      
        	
                Initial
                  Class Principal

              	 	
                Initial
                  Certificate

              
	
                Amount
                  of the Class M[__]

              	 	
                Principal
                  Amount of this

              
	
                Certificates:
                  $[__________]

              	 	
                Certificate:
                  $[__________]

              
	 	 	 
	
                Certificate
                  

              	 	
                Cut-off
                  Date: December 1, 2006

              
	
                Interest
                  Rate: Variable* 

                 

              	 	 
	
                NUMBER
                  [__]

              	 	
                CUSIP:
                  [__________]

              


      

      

        
          
            
              

            
*
            Subject
            to the Net Funds Cap, as provided in the Trust
            Agreement.

        

      

    

     

    
      
        
        

      

      
        A-2-3

        
          

        

      

      
        
        

      

    

     

    THIS
      CERTIFIES THAT CEDE & CO. is the registered owner of the Percentage Interest
      evidenced by this Certificate (obtained by dividing the Initial Certificate
      Principal Amount of this Certificate by the Initial Class Principal Amount
      of
      the Class M[__] Certificates, both as specified above) evidencing beneficial
      ownership in a Trust Fund consisting primarily of (i) a pool of certain
      conventional, second lien, fixed rate, fully amortizing and balloon, residential
      mortgage loans acquired by the Trust Fund on the Closing Date (the “Mortgage
      Loans”), together with all collections therefrom and proceeds thereof (excluding
      all scheduled payments of principal and interest due on the Mortgage Loans
      on or
      before the Cut-off Date), (ii) any REO Property, together with all collections
      thereon and proceeds thereof, (iii) the Depositor’s rights under the Mortgage
      Loan Sale Agreement and the Servicing Agreement (including any security interest
      created thereby), (iv) the Depositor’s rights under any insurance policies
      related to the Mortgage Loans, (v) amounts on deposit from time to time in
      the Collection Account, the Certificate Account and the Basis Risk Reserve
      Fund
      and (vi) the Supplemental Interest Trust, the primary assets of which are the
      Swap Agreement and all proceeds thereof.

     

    Distributions
      on this Certificate will be made on the 25th day of each month or, if such
      day
      is not a Business Day, then on the next succeeding Business Day, commencing
      in
      January 2007 (each, a “Distribution Date”), to the Person in whose name this
      Certificate is registered at the close of business on the Business Day
      immediately preceding such Distribution Date, so long as such Certificate is
      in
      book-entry form (the “Record Date”), in an amount equal to the product of the
      Percentage Interest evidenced by this Certificate and the amount, if any,
      required to be distributed to all the Certificates of the Class represented
      by
      this Certificate. All sums distributable on this Certificate are payable in
      the
      coin or currency of the United States of America which at the time of payment
      is
      legal tender for the payment of public and private debts.

     

    Reference
      is hereby made to the further provisions of this Certificate set forth on the
      reverse hereof, which shall have the same effect as though fully set forth
      on
      the face of this Certificate.

     

    Unless
      the certificate of authentication hereon has been executed by or on behalf
      of
      the Trustee, whose name appears below by manual signature, this Certificate
      shall not be entitled to any benefit under the Trust Agreement or be valid
      for
      any purpose.

     

    
      
        
        

      

      
        A-2-4

        
          

        

      

      
        
        

      

    

    


    IN
      WITNESS WHEREOF, the Trustee has caused this Certificate to be duly
      executed.

    
       

      
        	 	 	 
	 	CITIBANK,
                N.A., as
                Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                
AUTHORIZED
                SIGNATORY
	 	
                 

                Dated:
                  December _____, 2006

              


      

    

    


    


    TRUSTEE’S
      CERTIFICATE OF AUTHENTICATION

     

    This
      is
      one of the Certificates referred to in the within-mentioned Trust
      Agreement.

    
       

      
        	 	 	 
	 	CITIBANK,
                N.A., as
                Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                
AUTHORIZED
                SIGNATORY
	 	
                 

                Dated:
                  December _____, 2006

              


      

       

    

    
      
        
        

      

      
        A-2-5

        
          

        

      

      
        
        

      

       

    

    EXHIBIT
      A-3

    


    [FORM
      OF
      CLASS B CERTIFICATE]

     

    SOLELY
      FOR U.S. FEDERAL INCOME TAX PURPOSES, THIS CERTIFICATE REPRESENTS OWNERSHIP
      OF A
“REGULAR INTEREST” IN A “REAL ESTATE MORTGAGE INVESTMENT CONDUIT,” AS THOSE
      TERMS ARE DEFINED, RESPECTIVELY, IN SECTIONS 860G AND 860D OF THE INTERNAL
      REVENUE CODE OF 1986, AS AMENDED (THE “CODE”), AND A RIGHT TO RECEIVE PAYMENTS
      FROM THE BASIS RISK RESERVE FUND.

     

    THIS
      CERTIFICATE DOES NOT EVIDENCE AN OBLIGATION OF, OR AN INTEREST IN, AND IS NOT
      GUARANTEED BY, THE DEPOSITOR, THE TRUSTEE, THE MASTER SERVICER OR ANY AFFILIATE
      OF ANY OF THEM AND IS NOT INSURED OR GUARANTEED BY ANY GOVERNMENTAL AGENCY
      OR
      PRIVATE INSURER.

     

    DISTRIBUTIONS
      IN REDUCTION OF THE CERTIFICATE PRINCIPAL AMOUNT OF THIS CERTIFICATE MAY BE
      MADE
      IN INSTALLMENTS AS SET FORTH HEREIN. ACCORDINGLY, THE CERTIFICATE PRINCIPAL
      AMOUNT OF THIS CERTIFICATE AT ANY TIME MAY BE LESS THAN THE INITIAL CERTIFICATE
      PRINCIPAL AMOUNT OF THIS CERTIFICATE AS SET FORTH HEREIN.

     

    THIS
      CERTIFICATE IS SUBORDINATE IN RIGHT OF PAYMENT AS DESCRIBED IN THE TRUST
      AGREEMENT REFERRED TO HEREIN.

     

    THIS
      CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
      AMENDED, (THE “1933 ACT”) OR ANY STATE SECURITIES LAWS. NEITHER THIS CERTIFICATE
      NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE REOFFERED, SOLD, ASSIGNED,
      TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF [With
      respect to the Class B Regulation S Certificate Only: WITHIN THE UNITED STATES
      (AS DEFINED IN RULES 901 THROUGH 905 OF THE 1933 ACT (“REGULATION S”)) OR TO, OR
      FOR THE ACCOUNT OR BENEFIT OF, A U.S. PERSON (AS DEFINED IN REGULATION S),]
      IN
      THE
      ABSENCE OF SUCH REGISTRATION, UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT
      SUBJECT TO, REGISTRATION.

     

    [With
      respect to the Class B Rule 144A Certificate Only:] THE
      HOLDER OF THIS CERTIFICATE BY ITS ACCEPTANCE HEREOF AGREES TO OFFER, SELL OR
      OTHERWISE TRANSFER SUCH CERTIFICATE ONLY (A) PURSUANT TO A REGISTRATION
      STATEMENT WHICH HAS BEEN DECLARED EFFECTIVE UNDER THE 1933 ACT OR (B) TO A
      PERSON IT REASONABLY BELIEVES IS A “QUALIFIED INSTITUTIONAL BUYER” AS DEFINED IN
      RULE 144A UNDER THE 1933 ACT THAT PURCHASES FOR ITS OWN ACCOUNT OR FOR THE
      ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE
      TRANSFER IS BEING MADE IN RELIANCE ON RULE 144A, SUBJECT TO THE TRUSTEE’S RIGHT
      PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER TO REQUIRE THE DELIVERY OF A
      CERTIFICATE OF TRANSFER IN THE FORM APPEARING IN THE TRUST
      AGREEMENT.

     

    
      
        
        

      

      
        A-3-1

        
          

        

      

      
        
        

      

    

     

    [With
      respect to the Class B Regulation S Certificate Only:] THE
      HOLDER OF THIS CERTIFICATE BY ITS ACCEPTANCE HEREOF IS DEEMED TO HAVE
      REPRESENTED AND WARRANTED THAT (A) UNTIL THE EXPIRATION OF THE APPLICABLE
“DISTRIBUTION COMPLIANCE PERIOD” WITHIN THE MEANING OF REGULATION S, ANY OFFER,
      SALE, PLEDGE OR OTHER TRANSFER OF THIS CERTIFICATE SHALL NOT BE MADE IN THE
      UNITED STATES OR TO, OR FOR THE ACCOUNT OR BENEFIT OF, ANY U.S. PERSON (EACH
      AS
      DEFINED IN REGULATION S) AND (B) IF THIS CERTIFICATE IS HELD WITHIN THE UNITED
      STATES OR SUCH HOLDER IS A U.S. PERSON OR THIS CERTIFICATES IS HELD FOR THE
      ACCOUNT OR BENEFIT OF, A U.S. PERSON (EACH AS DEFINED IN REGULATION S) SUCH
      CERTIFICATE WAS ACQUIRED ONLY (1) PURSUANT TO A REGISTRATION STATEMENT WHICH
      HAS
      BEEN DECLARED EFFECTIVE UNDER THE 1933 ACT OR (2) BY SUCH HOLDER AS A “QUALIFIED
      INSTITUTIONAL BUYER” AS DEFINED IN RULE 144A UNDER THE 1933 ACT THAT PURCHASES
      FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO
      WHOM NOTICE IS GIVEN THAT THE TRANSFER IS BEING MADE IN RELIANCE ON RULE
      144A.

     

    UNLESS
      THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY
      TRUST COMPANY, A NEW YORK CORPORATION (“DTC”), TO THE ISSUER OR ITS AGENT FOR
      REGISTRATION OF TRANSFER, EXCHANGE, OR PAYMENT, AND ANY CERTIFICATE ISSUED
      IS
      REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED
      BY AN AUTHORIZED REPRESENTATIVE OF DTC AND ANY PAYMENT IS MADE TO CEDE & CO.
      OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF
      DTC,
      ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY
      PERSON IS WRONGFUL, INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS
      AN INTEREST HEREIN. 

     

    
      
         

      

      
        A-3-2

        
          

        

      

      
         

      

    

    NO
      TRANSFER OF THIS CERTIFICATE SHALL BE REGISTERED IF ITS RATING IS BELOW
      INVESTMENT GRADE UPON ACQUISITION UNLESS THE PROSPECTIVE TRANSFEREE PROVIDES
      THE
      TRUSTEE WITH (A) A CERTIFICATION TO THE EFFECT THAT SUCH TRANSFEREE (1) IS
      NEITHER AN EMPLOYEE BENEFIT PLAN OR OTHER RETIREMENT ARRANGEMENT SUBJECT TO
      SECTION 406 OF THE EMPLOYEE RETIREMENT INCOME SECURITY ACT OF 1974, AS AMENDED
      (“ERISA”), OR SECTION 4975 OF THE INTERNAL REVENUE CODE OF 1986, AS AMENDED (THE
“CODE”) (COLLECTIVELY, A “PLAN”), NOR A PERSON ACTING ON BEHALF OF ANY SUCH PLAN
      NOR A PERSON USING THE ASSETS OF ANY SUCH PLAN OR (2) IF SUCH TRANSFEREE IS
      AN
      INSURANCE COMPANY, SUCH TRANSFEREE IS PURCHASING SUCH CERTIFICATES WITH FUNDS
      CONTAINED IN AN “INSURANCE COMPANY GENERAL ACCOUNT” (AS SUCH TERM IS DEFINED IN
      SECTION V(e) OF THE PROHIBITED TRANSACTION CLASS EXEMPTION 95-60 (“PTCE 95-60”))
      AND THE PURCHASE AND HOLDING OF SUCH CERTIFICATES ARE COVERED UNDER SECTIONS
      I
      AND III OF PTCE 95-60; OR (B) AN OPINION OF COUNSEL SATISFACTORY TO THE TRUSTEE,
      AND UPON WHICH THE TRUSTEE, THE MASTER SERVICER AND THE DEPOSITOR SHALL BE
      ENTITLED TO RELY, TO THE EFFECT THAT THE PURCHASE OR HOLDING OF SUCH CERTIFICATE
      BY THE PROSPECTIVE TRANSFEREE WILL NOT RESULT IN ANY NON-EXEMPT PROHIBITED
      TRANSACTIONS UNDER TITLE I OF ERISA OR SECTION 4975 OF THE CODE AND WILL NOT
      SUBJECT THE TRUSTEE, THE MASTER SERVICER OR THE DEPOSITOR TO ANY OBLIGATION
      IN
      ADDITION TO THOSE UNDERTAKEN BY SUCH ENTITIES IN THE TRUST AGREEMENT, WHICH
      OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE TRUST FUND, THE TRUSTEE,
      THE
      MASTER SERVICER OR THE DEPOSITOR. A TRANSFEREE OF A BOOK-ENTRY CERTIFICATE
      SHALL
      BE DEEMED TO HAVE MADE A REPRESENTATION AS REQUIRED HEREIN.

     

    
      
        
        

      

      
        A-3-3

        
          

        

      

      
        
        

      

    

     

    STRUCTURED
      ASSET SECURITIES CORPORATION, SERIES 2006-S4

    MORTGAGE
      PASS-THROUGH CERTIFICATE, CLASS B1

     

    ([RULE
      144A/REGULATION S]) 

     

    Evidencing
      a beneficial interest in a pool consisting primarily of certain conventional,
      second lien, fixed rate, fully amortizing and balloon, residential mortgage
      loans and other assets in a trust fund established by:

     

    STRUCTURED
      ASSET SECURITIES CORPORATION

    

      
        	
                Initial
                  Class Principal

              	 	
                Initial
                  Certificate

              
	
                Amount
                  of the Class B1

              	 	
                Principal
                  Amount of this

              
	
                Certificates:
                  $[__________]

              	 	
                Certificate:
                  $[__________]

              
	 	 	 
	
                Certificate
                  

              	 	
                Cut-off
                  Date: December 1, 2006

              
	
                Interest
                  Rate: Variable* 

                 

              	 	 
	
                NUMBER
                  [__]

              	 	
                CUSIP:
                  [__________]

              
	 	 	
                [ISIN]:
                  [__________]

              


      

      

        
          
            
              

            
*
            Subject
            to the Net Funds Cap, as provided in the Trust
            Agreement.

        

      

    

     

    
      
        
        

      

      
        A-3-4

        
          

        

      

      
        
        

      

    

    


    THIS
      CERTIFIES THAT CEDE & CO. is the registered owner of the Percentage Interest
      evidenced by this Certificate (obtained by dividing the Initial Certificate
      Principal Amount of this Certificate by the Initial Class Principal Amount
      of
      the Class B1 Certificates, both as specified above) evidencing beneficial
      ownership in a Trust Fund consisting primarily of (i) a pool of certain
      conventional, second lien, fixed rate, fully amortizing and balloon, residential
      mortgage loans acquired by the Trust Fund on the Closing Date (the “Mortgage
      Loans”), together with all collections therefrom and proceeds thereof (excluding
      all scheduled payments of principal and interest due on the Mortgage Loans
      on or
      before the Cut-off Date), (ii) any REO Property, together with all collections
      thereon and proceeds thereof, (iii) the Depositor’s rights under the Mortgage
      Loan Sale Agreement and the Servicing Agreement (including any security interest
      created thereby), (iv) the Depositor’s rights under any insurance policies
      related to the Mortgage Loans, (v) amounts on deposit from time to time in
      the Collection Account, the Certificate Account and the Basis Risk Reserve
      Fund
      and (vi) the Supplemental Interest Trust, the primary assets of which are the
      Swap Agreement and all proceeds thereof.

     

    Distributions
      on this Certificate will be made on the 25th day of each month or, if such
      day
      is not a Business Day, then on the next succeeding Business Day, commencing
      in
      January 2007 (each, a “Distribution Date”), to the Person in whose name this
      Certificate is registered at the close of business on the Business Day
      immediately preceding such Distribution Date, so long as such Certificate is
      in
      book-entry form (the “Record Date”), in an amount equal to the product of the
      Percentage Interest evidenced by this Certificate and the amount, if any,
      required to be distributed to all the Certificates of the Class represented
      by
      this Certificate. All sums distributable on this Certificate are payable in
      the
      coin or currency of the United States of America which at the time of payment
      is
      legal tender for the payment of public and private debts.

     

    Reference
      is hereby made to the further provisions of this Certificate set forth on the
      reverse hereof, which shall have the same effect as though fully set forth
      on
      the face of this Certificate.

     

    Unless
      the certificate of authentication hereon has been executed by or on behalf
      of
      the Trustee, whose name appears below by manual signature, this Certificate
      shall not be entitled to any benefit under the Trust Agreement or be valid
      for
      any purpose.

     

    
      
        
        

      

      
        A-3-5

        
          

        

      

      
        
        

      

    

     

    IN
      WITNESS WHEREOF, the Trustee has caused this Certificate to be duly
      executed.

    
       

      
        	 	 	 
	 	CITIBANK,
                N.A., as
                Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                
AUTHORIZED
                SIGNATORY
	 	
                 

                Dated:
                  December _____, 2006

              


      

    

     

    TRUSTEE’S
      CERTIFICATE OF AUTHENTICATION

     

    This
      is
      one of the Certificates referred to in the within-mentioned Trust
      Agreement.

    
      
         

        
          	 	 	 
	 	CITIBANK,
                  N.A., as
                  Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                  
AUTHORIZED
                  SIGNATORY
	 	
                   

                  Dated:
                    December _____, 2006

                


        

      

       

      
        
          
          

        

        
          A-3-6

          
            

          

        

        
          
          

        

      

       

    

    EXHIBIT
      A-4

    


    [FORM
      OF
      CLASS P CERTIFICATE]

    


    SOLELY
      FOR U.S. FEDERAL INCOME TAX PURPOSES, THIS CERTIFICATE REPRESENTS OWNERSHIP
      OF A
“REGULAR INTEREST” IN A “REAL ESTATE MORTGAGE INVESTMENT CONDUIT,” AS THOSE
      TERMS ARE DEFINED, RESPECTIVELY, IN SECTIONS 860G AND 860D OF THE INTERNAL
      REVENUE CODE OF 1986, AS AMENDED (THE “CODE”).

     

    THIS
      CERTIFICATE DOES NOT EVIDENCE AN OBLIGATION OF, OR AN INTEREST IN, AND IS NOT
      GUARANTEED BY, THE DEPOSITOR, THE TRUSTEE, THE MASTER SERVICER OR ANY AFFILIATE
      OF ANY OF THEM AND IS NOT INSURED OR GUARANTEED BY ANY GOVERNMENTAL AGENCY
      OR
      PRIVATE INSURER.

     

    THIS
      CERTIFICATE IS NOT ENTITLED TO SCHEDULED DISTRIBUTIONS OF PRINCIPAL AND WILL
      NOT
      ACCRUE INTEREST. THE HOLDER OF THIS CERTIFICATE WILL BE ENTITLED TO CERTAIN
      DISTRIBUTIONS AS PROVIDED IN THE TRUST AGREEMENT.

     

    THIS
      CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
      AMENDED, (THE “1933 ACT”) OR ANY STATE SECURITIES LAWS. NEITHER THIS CERTIFICATE
      NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE REOFFERED, SOLD, ASSIGNED,
      TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF
      SUCH
      REGISTRATION, UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT SUBJECT TO,
      REGISTRATION.

     

    THE
      HOLDER OF THIS CERTIFICATE BY ITS ACCEPTANCE HEREOF AGREES TO OFFER, SELL OR
      OTHERWISE TRANSFER SUCH CERTIFICATE ONLY (A) PURSUANT TO A REGISTRATION
      STATEMENT WHICH HAS BEEN DECLARED EFFECTIVE UNDER THE 1933 ACT OR (B) TO A
      PERSON IT REASONABLY BELIEVES IS A “QUALIFIED INSTITUTIONAL BUYER” AS DEFINED IN
      RULE 144A UNDER THE 1933 ACT THAT PURCHASES FOR ITS OWN ACCOUNT OR FOR THE
      ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE
      TRANSFER IS BEING MADE IN RELIANCE ON RULE 144A, SUBJECT TO THE TRUSTEE’S RIGHT
      PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER TO REQUIRE THE DELIVERY OF A
      CERTIFICATE OF TRANSFER IN THE FORM APPEARING IN THE TRUST
      AGREEMENT.

     

    
      
         

      

      
        A-4-1

        
          

        

      

      
         

      

    

    NO
      TRANSFER OF THIS CERTIFICATE SHALL BE REGISTERED UNLESS THE PROSPECTIVE
      TRANSFEREE PROVIDES THE TRUSTEE WITH (A) A CERTIFICATION TO THE EFFECT THAT
      SUCH
      TRANSFEREE (1) IS NEITHER AN EMPLOYEE BENEFIT PLAN OR OTHER RETIREMENT
      ARRANGEMENT SUBJECT TO SECTION 406 OF THE EMPLOYEE RETIREMENT INCOME SECURITY
      ACT OF 1974, AS AMENDED (“ERISA”), OR SECTION 4975 OF THE INTERNAL REVENUE CODE
      OF 1986, AS AMENDED (THE “CODE”) (COLLECTIVELY, A “PLAN”), NOR A PERSON ACTING
      ON BEHALF OF ANY SUCH PLAN NOR A PERSON USING THE ASSETS OF ANY SUCH PLAN OR
      (2)
      IF THE CERTIFICATE HAS BEEN THE SUBJECT OF AN ERISA-QUALIFYING UNDERWRITING
      AND
      THE TRANSFEREE IS AN INSURANCE COMPANY, SUCH TRANSFEREE IS PURCHASING SUCH
      CERTIFICATE WITH FUNDS CONTAINED IN AN “INSURANCE COMPANY GENERAL ACCOUNT” (AS
      SUCH TERM IS DEFINED IN SECTION V(e) OF THE PROHIBITED TRANSACTION CLASS
      EXEMPTION 95-60 (“PTCE 95-60”)) AND THE PURCHASE AND HOLDING OF SUCH CERTIFICATE
      ARE COVERED UNDER SECTIONS I AND III OF PTCE 95-60; OR (B) AN OPINION OF COUNSEL
      SATISFACTORY TO THE TRUSTEE, AND UPON WHICH THE TRUSTEE, THE MASTER SERVICER
      AND
      THE DEPOSITOR SHALL BE ENTITLED TO RELY, TO THE EFFECT THAT THE PURCHASE OR
      HOLDING OF SUCH CERTIFICATE BY THE PROSPECTIVE TRANSFEREE WILL NOT RESULT IN
      ANY
      NON-EXEMPT PROHIBITED TRANSACTIONS UNDER TITLE I OF ERISA OR SECTION 4975 OF
      THE
      CODE AND WILL NOT SUBJECT THE TRUSTEE, THE MASTER SERVICER OR THE DEPOSITOR
      TO
      ANY OBLIGATION IN ADDITION TO THOSE UNDERTAKEN BY SUCH ENTITIES IN THE TRUST
      AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE TRUST FUND,
      THE TRUSTEE, THE MASTER SERVICER OR THE DEPOSITOR. 

     

    
      
        
        

      

      
        A-4-2

        
          

        

      

      
        
        

      

       

    

    STRUCTURED
      ASSET SECURITIES CORPORATION, SERIES 2006-S4

    MORTGAGE
      PASS-THROUGH CERTIFICATE, CLASS P

     

    Evidencing
      a beneficial interest in a pool consisting primarily of certain conventional,
      second lien, fixed rate, fully amortizing and balloon, residential mortgage
      loans and other assets in a trust fund established by:

     

    STRUCTURED
      ASSET SECURITIES CORPORATION

    


    Percentage
      Interest: 100%                     Cut-off
      Date: December 1, 2006

    


    NUMBER
      [__]

     

    
      
        
        

      

      
        A-4-3

        
          

        

      

      
        
        

      

    

    


    THIS
      CERTIFIES THAT TFINN & CO. (on behalf of Lehman Pass-Through Securities
      Inc.) is the registered owner of the Percentage Interest evidenced by this
      Certificate evidencing a beneficial ownership in certain distributions of
      Prepayment Premiums (as defined in the Trust Agreement) made in respect of
      certain conventional, second lien, fixed rate, fully amortizing and balloon,
      residential mortgage loans (the “Mortgage Loans”) acquired from Structured Asset
      Securities Corporation (the “Depositor”), a Delaware corporation, which from
      time to time may be held in the Trust Fund established pursuant to the Trust
      Agreement (as defined on the reverse hereof).

     

    Distributions
      on this Certificate will be made on the 25th day of each month or, if such
      day
      is not a Business Day, then on the next succeeding Business Day, commencing
      in
      January 2007 (each, a “Distribution Date”), to the Person in whose name this
      Certificate is registered at the close of business on the last Business Day
      of
      the calendar month immediately preceding the month in which such Distribution
      Date occurs (or, in the case of the first Distribution Date, the Closing Date),
      so long as such Certificate is in book-entry form (the “Record Date”), in an
      amount equal to the product of the Percentage Interest evidenced by this
      Certificate and the amount, if any, required to be distributed to all the
      Certificates of the Class represented by this Certificate. All sums
      distributable on this Certificate are payable in the coin or currency of the
      United States of America which at the time of payment is legal tender for the
      payment of public and private debts.

     

    Reference
      is hereby made to the further provisions of this Certificate set forth on the
      reverse hereof, which shall have the same effect as though fully set forth
      on
      the face of this Certificate.

     

    Unless
      the certificate of authentication hereon has been executed by or on behalf
      of
      the Trustee, whose name appears below by manual signature, this Certificate
      shall not be entitled to any benefit under the Trust Agreement or be valid
      for
      any purpose. 

     

    
      
        
        

      

      
        A-4-4

        
          

        

      

      
        
        

      

    

    


    IN
      WITNESS WHEREOF, the Trustee has caused this Certificate to be duly
      executed.

     
      
        
          	 	 	 
	 	CITIBANK,
                  N.A., as
                  Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                  
AUTHORIZED
                  SIGNATORY
	 	
                   

                  Dated:
                    December _____, 2006

                


        

      

    

    


    TRUSTEE’S
      CERTIFICATE OF AUTHENTICATION

     

    This
      is
      one of the Certificates referred to in the within-mentioned Trust
      Agreement.

     
      
      
        
          	 	 	 
	 	CITIBANK,
                  N.A., as
                  Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                  
AUTHORIZED
                  SIGNATORY
	 	
                   

                  Dated:
                    December _____, 2006

                


        

      

       

      
        
          
          

        

        
          A-4-5

          
            

          

        

        
          
          

        

      

    

     

    EXHIBIT
      A-5

    


    [FORM
      OF
      CLASS X CERTIFICATE]

     

    SOLELY
      FOR U.S. FEDERAL INCOME TAX PURPOSES, THIS CERTIFICATE REPRESENTS OWNERSHIP
      OF A
“REGULAR INTEREST” IN A “REAL ESTATE MORTGAGE INVESTMENT CONDUIT,” AS THOSE
      TERMS ARE DEFINED, RESPECTIVELY, IN SECTIONS 860G AND 860D OF THE INTERNAL
      REVENUE CODE OF 1986, AS AMENDED (THE “CODE”), AND A RIGHT TO RECEIVE PAYMENTS
      FROM THE BASIS RISK RESERVE FUND.

     

    THIS
      CERTIFICATE DOES NOT EVIDENCE AN OBLIGATION OF, OR AN INTEREST IN, AND IS NOT
      GUARANTEED BY, THE DEPOSITOR, THE TRUSTEE, THE MASTER SERVICER OR ANY AFFILIATE
      OF ANY OF THEM AND IS NOT INSURED OR GUARANTEED BY ANY GOVERNMENTAL AGENCY
      OR
      PRIVATE INSURER.

     

    THIS
      CERTIFICATE IS NOT ENTITLED TO SCHEDULED DISTRIBUTIONS OF PRINCIPAL AND WILL
      NOT
      ACCRUE INTEREST. THE HOLDER OF THIS CERTIFICATE WILL BE ENTITLED TO CERTAIN
      DISTRIBUTIONS AS PROVIDED IN THE TRUST AGREEMENT.

     

    THIS
      CERTIFICATE IS SUBORDINATE IN RIGHT OF PAYMENT AS DESCRIBED IN THE TRUST
      AGREEMENT REFERRED TO HEREIN.

     

    THIS
      CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS
      AMENDED, (THE “1933 ACT”) OR ANY STATE SECURITIES LAWS. NEITHER THIS CERTIFICATE
      NOR ANY INTEREST OR PARTICIPATION HEREIN MAY BE REOFFERED, SOLD, ASSIGNED,
      TRANSFERRED, PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF
      SUCH
      REGISTRATION, UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT SUBJECT TO,
      REGISTRATION.

     

    THE
      HOLDER OF THIS CERTIFICATE BY ITS ACCEPTANCE HEREOF AGREES TO OFFER, SELL OR
      OTHERWISE TRANSFER SUCH CERTIFICATE ONLY (A) PURSUANT TO A REGISTRATION
      STATEMENT WHICH HAS BEEN DECLARED EFFECTIVE UNDER THE 1933 ACT, (B) TO A PERSON
      IT REASONABLY BELIEVES IS A “QUALIFIED INSTITUTIONAL BUYER” AS DEFINED IN RULE
      144A UNDER THE 1933 ACT THAT PURCHASES FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT
      OF
      A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS
      BEING MADE IN RELIANCE ON RULE 144A, OR (C) TO AN INSTITUTIONAL “ACCREDITED
      INVESTOR” WITHIN THE MEANING OF SUBPARAGRAPH (A)(1), (2), (3) OR (7) OF RULE 501
      UNDER THE 1933 ACT THAT IS ACQUIRING THE CERTIFICATE FOR ITS OWN ACCOUNT, OR
      FOR
      THE ACCOUNT OF SUCH AN INSTITUTIONAL “ACCREDITED INVESTOR,” FOR INVESTMENT
      PURPOSES AND NOT WITH A VIEW TO, OR FOR OFFER OR SALE IN CONNECTION WITH, ANY
      DISTRIBUTION IN VIOLATION OF THE 1933 ACT, SUBJECT TO THE TRUSTEE’S RIGHT PRIOR
      TO ANY SUCH OFFER, SALE OR TRANSFER TO REQUIRE THE DELIVERY OF A CERTIFICATE
      OF
      TRANSFER IN THE FORM APPEARING IN THE TRUST AGREEMENT.

     

    
      
        
        

      

      
        A-5-1

        
          

        

      

      
        
        

      

    

     

    NO
      TRANSFER OF THIS CERTIFICATE SHALL BE REGISTERED UNLESS THE PROSPECTIVE
      TRANSFEREE PROVIDES THE TRUSTEE WITH (A) A CERTIFICATION TO THE EFFECT THAT
      SUCH
      TRANSFEREE (1) IS NEITHER AN EMPLOYEE BENEFIT PLAN OR OTHER RETIREMENT
      ARRANGEMENT SUBJECT TO SECTION 406 OF THE EMPLOYEE RETIREMENT INCOME SECURITY
      ACT OF 1974, AS AMENDED (“ERISA”), OR SECTION 4975 OF THE INTERNAL REVENUE CODE
      OF 1986, AS AMENDED (THE “CODE”) (COLLECTIVELY, A “PLAN”), NOR A PERSON ACTING
      ON BEHALF OF ANY SUCH PLAN NOR A PERSON USING THE ASSETS OF ANY SUCH PLAN OR
      (2)
      IF THE CERTIFICATE HAS BEEN THE SUBJECT OF AN ERISA-QUALIFYING UNDERWRITING
      AND
      THE TRANSFEREE IS AN INSURANCE COMPANY, SUCH TRANSFEREE IS PURCHASING SUCH
      CERTIFICATE WITH FUNDS CONTAINED IN AN “INSURANCE COMPANY GENERAL ACCOUNT” (AS
      SUCH TERM IS DEFINED IN SECTION V(e) OF THE PROHIBITED TRANSACTION CLASS
      EXEMPTION 95-60 (“PTCE 95-60”)) AND THE PURCHASE AND HOLDING OF SUCH CERTIFICATE
      ARE COVERED UNDER SECTIONS I AND III OF PTCE 95-60; OR (B) AN OPINION OF COUNSEL
      SATISFACTORY TO THE TRUSTEE, AND UPON WHICH THE TRUSTEE, THE MASTER SERVICER
      AND
      THE DEPOSITOR SHALL BE ENTITLED TO RELY, TO THE EFFECT THAT THE PURCHASE OR
      HOLDING OF SUCH CERTIFICATE BY THE PROSPECTIVE TRANSFEREE WILL NOT RESULT IN
      ANY
      NON-EXEMPT PROHIBITED TRANSACTIONS UNDER TITLE I OF ERISA OR SECTION 4975 OF
      THE
      CODE AND WILL NOT SUBJECT THE TRUSTEE, THE MASTER SERVICER OR THE DEPOSITOR
      TO
      ANY OBLIGATION IN ADDITION TO THOSE UNDERTAKEN BY SUCH ENTITIES IN THE TRUST
      AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE TRUST FUND,
      THE TRUSTEE, THE MASTER SERVICER OR THE DEPOSITOR. 

    


    
      
        
        

      

      
        A-5-2

        
          

        

      

      
        
        

      

    

     

    STRUCTURED
      ASSET SECURITIES CORPORATION, SERIES 2006-S4

    MORTGAGE
      PASS-THROUGH CERTIFICATE, CLASS X

     

    Evidencing
      a beneficial interest in a pool consisting primarily of certain conventional,
      second lien, fixed rate, fully amortizing and balloon, residential mortgage
      loans and other assets in a trust fund established by:

     

    STRUCTURED
      ASSET SECURITIES CORPORATION

     

    Percentage
      Interest: 100%     Cut-off
      Date: December 1, 2006

     

    NUMBER
      [__]

     

    
      
        
        

      

      
        A-5-3

        
          

        

      

      
        
        

      

    

    


    THIS
      CERTIFIES THAT TFINN & CO. (on behalf of Lehman Pass-Through Securities
      Inc.) is the registered owner of the Percentage Interest evidenced by this
      Certificate evidencing beneficial ownership in a Trust Fund consisting primarily
      of (i) a pool of certain conventional, second lien, fixed rate, fully amortizing
      and balloon, residential mortgage loans acquired by the Trust Fund on the
      Closing Date (the “Mortgage Loans”), together with all collections therefrom and
      proceeds thereof (excluding all scheduled payments of principal and interest
      due
      on the Mortgage Loans on or before the Cut-off Date), (ii) any REO Property,
      together with all collections thereon and proceeds thereof, (iii) the
      Depositor’s rights under the Mortgage Loan Sale Agreement and each Servicing
      Agreement (including any security interest created thereby), (iv) amounts on
      deposit from time to time in the Collection Account, the Certificate Account
      and
      the Basis Risk Reserve Fund and (v) the Supplemental Interest Trust, the primary
      assets of which are the Swap Agreement and all proceeds thereof.

     

    Distributions
      on this Certificate will be made on the 25th day of each month or, if such
      day
      is not a Business Day, then on the next succeeding Business Day, commencing
      in
      January 2007 (each, a “Distribution Date”), to the Person in whose name this
      Certificate is registered at the close of business on the last Business Day
      of
      the calendar month immediately preceding the month in which such Distribution
      Date occurs (or, in the case of the first Distribution Date, the Closing Date),
      so long as such Certificate is in book-entry form (the “Record Date”), in an
      amount equal to the product of the Percentage Interest evidenced by this
      Certificate and the amount, if any, required to be distributed to all the
      Certificates of the Class represented by this Certificate. All sums
      distributable on this Certificate are payable in the coin or currency of the
      United States of America which at the time of payment is legal tender for the
      payment of public and private debts.

     

    Reference
      is hereby made to the further provisions of this Certificate set forth on the
      reverse hereof, which shall have the same effect as though fully set forth
      on
      the face of this Certificate.

     

    Unless
      the certificate of authentication hereon has been executed by or on behalf
      of
      the Trustee, whose name appears below by manual signature, this Certificate
      shall not be entitled to any benefit under the Trust Agreement or be valid
      for
      any purpose. 

     

    
      
        
        

      

      
        A-5-4

        
          

        

      

      
        
        

      

    

     

    IN
      WITNESS WHEREOF, the Trustee has caused this Certificate to be duly
      executed.

     
      
        
          	 	 	 
	 	CITIBANK,
                  N.A., as
                  Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                  
AUTHORIZED
                  SIGNATORY
	 	
                   

                  Dated:
                    December _____, 2006

                


        

      

    

    


    TRUSTEE’S
      CERTIFICATE OF AUTHENTICATION

     

    This
      is
      one of the Certificates referred to in the within-mentioned Trust
      Agreement.

     
      
        
          	 	 	 
	 	CITIBANK,
                  N.A., as
                  Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                  
AUTHORIZED
                  SIGNATORY
	 	
                   

                  Dated:
                    December _____, 2006

                


        

      

       

      
        
          
          

        

        
          A-5-5

          
            

          

        

        
          
          

        

         

      

    

    EXHIBIT
      A-6

     

    [FORM
      OF
      RESIDUAL CERTIFICATE]

     

    THIS
      CERTIFICATE IS A REMIC RESIDUAL INTEREST CERTIFICATE. THIS CERTIFICATE DOES
      NOT
      EVIDENCE AN OBLIGATION OF, OR AN INTEREST IN, AND IS NOT GUARANTEED BY, THE
      DEPOSITOR, THE TRUSTEE, THE MASTER SERVICER OR ANY AFFILIATE OF ANY OF THEM
      AND
      IS NOT INSURED OR GUARANTEED BY ANY GOVERNMENTAL AGENCY OR PRIVATE
      INSURER.

     

    THIS
      CERTIFICATE IS NOT ENTITLED TO DISTRIBUTIONS OF PRINCIPAL AND WILL NOT ACCRUE
      INTEREST. THE HOLDER OF THIS CERTIFICATE WILL BE ENTITLED ONLY TO CERTAIN
      LIMITED DISTRIBUTIONS AS PROVIDED IN THE TRUST AGREEMENT.

     

    THIS
      CERTIFICATE IS SUBORDINATE IN RIGHT OF PAYMENT AS DESCRIBED IN THE TRUST
      AGREEMENT REFERRED TO HEREIN.

     

    THIS
      CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED
      (THE “1933 ACT”), OR ANY STATE SECURITIES LAWS. NEITHER THIS CERTIFICATE NOR ANY
      INTEREST OR PARTICIPATION HEREIN MAY BE REOFFERED, SOLD, ASSIGNED, TRANSFERRED,
      PLEDGED, ENCUMBERED OR OTHERWISE DISPOSED OF IN THE ABSENCE OF SUCH
      REGISTRATION, UNLESS SUCH TRANSACTION IS EXEMPT FROM, OR NOT SUBJECT TO,
      REGISTRATION.

     

    THE
      HOLDER OF THIS CERTIFICATE BY ITS ACCEPTANCE HEREOF AGREES TO OFFER, SELL OR
      OTHERWISE TRANSFER SUCH CERTIFICATE ONLY (A) PURSUANT TO A REGISTRATION
      STATEMENT WHICH HAS BEEN DECLARED EFFECTIVE UNDER THE 1933 ACT, (B) TO A PERSON
      IT REASONABLY BELIEVES IS A “QUALIFIED INSTITUTIONAL BUYER” AS DEFINED IN RULE
      144A UNDER THE 1933 ACT THAT PURCHASES FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT
      OF
      A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE TRANSFER IS
      BEING MADE IN RELIANCE ON RULE 144A, OR (C) PURSUANT TO ANOTHER AVAILABLE
      EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE 1933 ACT, SUBJECT TO THE
      TRUSTEE’S RIGHT PRIOR TO ANY SUCH OFFER, SALE OR TRANSFER TO REQUIRE THE
      DELIVERY OF A CERTIFICATE OF TRANSFER IN THE FORM APPEARING IN THE TRUST
      AGREEMENT.

     

    NEITHER
      THIS CERTIFICATE, NOR ANY BENEFICIAL INTEREST IN THIS CERTIFICATE, MAY BE
      TRANSFERRED, SOLD, PLEDGED, OR OTHERWISE DISPOSED OF UNLESS PRIOR TO SUCH
      DISPOSITION, THE PROPOSED TRANSFEREE DELIVERS TO THE TRUSTEE (I) AN AFFIDAVIT
      STATING (A) THAT THE PROPOSED TRANSFEREE IS NOT A “DISQUALIFIED ORGANIZATION”
WITHIN THE MEANING OF SECTION 860E(E)(5) OF THE INTERNAL REVENUE CODE OF 1986,
      AS AMENDED (THE “CODE”) AND IS NOT PURCHASING THE CERTIFICATE ON BEHALF OF A
      DISQUALIFIED ORGANIZATION, (B) THAT NO PURPOSE OF SUCH TRANSFER IS TO AVOID
      OR
      IMPEDE THE ASSESSMENT OR COLLECTION OF TAX, (C) IN THE CASE OF A NON-U.S.
      PERSON, THAT THE PROPOSED TRANSFEREE IS A NON-U.S. PERSON THAT HOLDS A RESIDUAL
      CERTIFICATE IN CONNECTION WITH THE CONDUCT OF A TRADE OR BUSINESS WITHIN THE
      UNITED STATES AND HAS FURNISHED THE TRANSFEROR AND THE TRUSTEE WITH AN EFFECTIVE
      INTERNAL REVENUE SERVICE FORM 4224 OR SUCCESSOR FORM AT THE TIME AND IN THE
      MANNER REQUIRED BY THE CODE.

     

    
      
        
        

      

      
        A-6-1

        
          

        

      

      
        
        

      

    

     

    NO
      TRANSFER OF THIS CERTIFICATE SHALL BE REGISTERED UNLESS THE PROSPECTIVE
      TRANSFEREE PROVIDES THE TRUSTEE WITH (A) A CERTIFICATION TO THE EFFECT THAT
      SUCH
      TRANSFEREE (1) IS NEITHER AN EMPLOYEE BENEFIT PLAN OR OTHER RETIREMENT
      ARRANGEMENT SUBJECT TO SECTION 406 OF THE EMPLOYEE RETIREMENT INCOME SECURITY
      ACT OF 1974, AS AMENDED (“ERISA”), OR SECTION 4975 OF THE INTERNAL REVENUE CODE
      OF 1986, AS AMENDED (THE “CODE”) (COLLECTIVELY, A “PLAN”), NOR A PERSON ACTING
      ON BEHALF OF ANY SUCH PLAN NOR A PERSON USING THE ASSETS OF ANY SUCH PLAN OR
      (2)
      IF THE CERTIFICATE HAS BEEN THE SUBJECT OF AN ERISA-QUALIFYING UNDERWRITING
      AND
      THE TRANSFEREE IS AN INSURANCE COMPANY, SUCH TRANSFEREE IS PURCHASING SUCH
      CERTIFICATE WITH FUNDS CONTAINED IN AN “INSURANCE COMPANY GENERAL ACCOUNT” (AS
      SUCH TERM IS DEFINED IN SECTION V(e) OF THE PROHIBITED TRANSACTION CLASS
      EXEMPTION 95-60 (“PTCE 95-60”)) AND THE PURCHASE AND HOLDING OF SUCH CERTIFICATE
      ARE COVERED UNDER SECTIONS I AND III OF PTCE 95-60; OR (B) AN OPINION OF COUNSEL
      SATISFACTORY TO THE TRUSTEE, AND UPON WHICH THE TRUSTEE, THE MASTER SERVICER
      AND
      THE DEPOSITOR SHALL BE ENTITLED TO RELY, TO THE EFFECT THAT THE PURCHASE OR
      HOLDING OF SUCH CERTIFICATE BY THE PROSPECTIVE TRANSFEREE WILL NOT RESULT IN
      ANY
      NON-EXEMPT PROHIBITED TRANSACTIONS UNDER TITLE I OF ERISA OR SECTION 4975 OF
      THE
      CODE AND WILL NOT SUBJECT THE TRUSTEE, THE MASTER SERVICER OR THE DEPOSITOR
      TO
      ANY OBLIGATION IN ADDITION TO THOSE UNDERTAKEN BY SUCH ENTITIES IN THE TRUST
      AGREEMENT, WHICH OPINION OF COUNSEL SHALL NOT BE AN EXPENSE OF THE TRUST FUND,
      THE TRUSTEE, THE MASTER SERVICER OR THE DEPOSITOR. 

     

    
      
        
        

      

      
        A-6-2

        
          

        

      

      
        
        

      

    

     

    STRUCTURED
      ASSET SECURITIES CORPORATION, SERIES 2006-S4

    MORTGAGE
      PASS-THROUGH CERTIFICATE, CLASS [___]

     

    Evidencing
      a beneficial interest in a pool consisting primarily of certain conventional,
      second lien, fixed rate, fully amortizing and balloon, residential mortgage
      loans and other assets in a trust fund established by:

     

    STRUCTURED
      ASSET SECURITIES CORPORATION

     

    Percentage
      Interest: 100%    Cut-off
      Date: December 1, 2006

    


    NUMBER
      [__]  

     

    
      
        
        

      

      
        A-6-3

        
          

        

      

      
        
        

      

    

     

    THIS
      CERTIFIES THAT TFINN & CO. is the registered owner of the Percentage
      Interest evidenced by this Certificate evidencing beneficial ownership in a
      Trust Fund consisting primarily of (i) a pool of certain conventional, second
      lien, fixed rate, fully amortizing and balloon, residential mortgage loans
      acquired by the Trust Fund on the Closing Date (the “Mortgage Loans”), together
      with all collections therefrom and proceeds thereof (excluding all scheduled
      payments of principal and interest due on the Mortgage Loans on or before the
      Cut-off Date), (ii) any REO Property, together with all collections thereon
      and
      proceeds thereof, (iii) the Depositor’s rights under the Mortgage Loan Sale
      Agreement and each Servicing Agreement (including any security interest created
      thereby), (iv) amounts on deposit from time to time in the Collection Account,
      the Certificate Account and the Basis Risk Reserve Fund and (v) the Supplemental
      Interest Trust, the primary assets of which are the Swap Agreement and all
      proceeds thereof.

     

    Distributions
      on this Certificate will be made on the 25th day of each month or, if such
      day
      is not a Business Day, then on the next succeeding Business Day, commencing
      in
      January 2007 (each, a “Distribution Date”), to the Person in whose name this
      Certificate is registered at the close of business on the last Business Day
      of
      the calendar month immediately preceding the month in which such Distribution
      Date occurs (or, in the case of the first Distribution Date, the Closing Date),
      so long as such Certificate is in book-entry form (the “Record Date”), in an
      amount equal to the product of the Percentage Interest evidenced by this
      Certificate and the amount, if any, required to be distributed to all the
      Certificates of the Class represented by this Certificate. All sums
      distributable on this Certificate are payable in the coin or currency of the
      United States of America which at the time of payment is legal tender for the
      payment of public and private debts.

     

    Reference
      is hereby made to the further provisions of this Certificate set forth on the
      reverse hereof, which shall have the same effect as though fully set forth
      on
      the face of this Certificate.

     

    Unless
      the certificate of authentication hereon has been executed by or on behalf
      of
      the Trustee, whose name appears below by manual signature, this Certificate
      shall not be entitled to any benefit under the Trust Agreement or be valid
      for
      any purpose.

     

    
      
        
        

      

      
        A-6-4

        
          

        

      

      
        
        

      

    

     

    IN
      WITNESS WHEREOF, the Trustee has caused this Certificate to be duly
      executed.

     
      
        
          	 	 	 
	 	CITIBANK,
                  N.A., as
                  Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                  
AUTHORIZED
                  SIGNATORY
	 	
                   

                  Dated:
                    December _____, 2006

                


        

      

    

    


    TRUSTEE’S
      CERTIFICATE OF AUTHENTICATION

     

    This
      is
      one of the Certificates referred to in the within-mentioned Trust
      Agreement.

     
      
        
          	 	 	 
	 	CITIBANK,
                  N.A., as
                  Trustee
	 
 	 
 	 
 
	 	By:  	 
	 	
                  
AUTHORIZED
                  SIGNATORY
	 	
                   

                  Dated:
                    December _____, 2006

                


        

      

       

      
        
          
          

        

        
          A-6-5

          
            

          

        

        
          
          

        

         

      

    

    EXHIBIT
      A-7

    


    [FORM
      OF
      REVERSE OF CERTIFICATE]

     

    STRUCTURED
      ASSET SECURITIES CORPORATION

    MORTGAGE
      PASS-THROUGH CERTIFICATE, SERIES 2006-S4

     

    This
      Certificate is one of a duly authorized issue of certificates designated as
      Structured Asset Securities Corporation Mortgage Pass-Through Certificates,
      Series 2006-S4 (the “Certificates”), representing all or part of a beneficial
      ownership interest in the Trust Fund established pursuant to a Trust Agreement
      dated as of December 1, 2006 (the “Trust Agreement”), among Structured
      Asset Securities Corporation, as Depositor, Citibank, N.A., as Trustee, Aurora
      Loan Services LLC, as Master Servicer, and Clayton Fixed Income Services Inc.,
      as Credit Risk Manager, to which terms, provisions and conditions thereof the
      Holder of this Certificate by virtue of the acceptance hereof assents, and
      by
      which such Holder is bound. The Certificates consist of the following Classes:
      the Class A, Class M1, Class M2, Class M3, Class M4, Class M5, Class M6, Class
      M7, Class M8, Class M9, Class B1, Class B2, Class P, Class X, Class LT-R and
      Class R Certificates.

     

    On
      each
      Distribution Date, the Total Distribution Amount for such date will be
      distributed from the Certificate Account to Holders of the Certificates
      according to the terms of the Trust Agreement. All distributions or allocations
      made with respect to each Class of Certificates on each Distribution Date shall
      be allocated among the outstanding Certificates of such Class based on the
      Certificate Principal Amount (or Percentage Interest) of each such
      Certificate.

     

    Distributions
      on this Certificate will be made by wire transfer in immediately available
      funds
      to the Holder of record of this Certificate on the immediately preceding Record
      Date to an account specified in writing by such Holder to the Trustee at least
      five (5) Business Days prior to the first Distribution Date to such Holder.
      Wire
      transfers will be made at the expense of the Holder requesting the same by
      deducting a wire transfer fee from the related distribution. The final
      distribution on this Certificate will be made, after due notice to the Holder
      of
      the pendency of such distribution, only upon presentation and surrender of
      this
      Certificate at the Corporate Trust Office (as defined below).

     

    The
      Corporate Trust Office with respect to the presentment and surrender of
      Certificates for the final distribution thereon and the presentment and
      surrender of the Certificates for any other purpose is the corporate trust
      office of the Trustee at Citibank, N.A., 111 Wall Street, 15th
      Floor,
      New York, New York 10005, Attention: 15th
      Floor
      Window. The Trustee may designate another address from time to time by notice
      to
      the Holders of the Certificates and the Depositor. The Trustee has executed
      this
      Certificate solely in its capacity as Trustee under the Trust Agreement and
      not
      individually, and the Trustee shall be liable hereunder only in respect of
      the
      assets of the Trust Fund.

    


    The
      Trust
      Agreement permits the amendment thereof from time to time by the Depositor,
      the
      Master Servicer and the Trustee with the consent of the Holders of not less
      than
      66 2/3% of the Class Principal Amount (or Percentage Interest) of each Class
      of
      Certificates affected thereby for the purpose of adding, changing or eliminating
      any provisions of the Trust Agreement or modifying the rights of the Holders
      of
      the Certificates thereunder, as provided in the Trust Agreement. Any consent
      by
      the Holder of this Certificate will be conclusive and binding on such Holder
      and
      upon all future Holders of this Certificate and of any Certificate issued upon
      the transfer hereof or in exchange herefor or in lieu hereof whether or not
      notation of such consent is made upon this Certificate. The Trust Agreement
      also
      permits the amendment thereof, in certain limited circumstances, without the
      consent of the Holders of any of the Certificates.

     

    
      
        
        

      

      
        A-7-1

        
          

        

      

      
        
        

      

    

     

    As
      provided in the Trust Agreement and subject to certain limitations therein
      set
      forth, the transfer of this Certificate is registerable in the Certificate
      Register upon surrender of this Certificate for registration of transfer at
      the
      applicable Corporate Trust Office, duly endorsed by, or accompanied by a written
      instrument of transfer in form satisfactory to the Certificate Registrar, duly
      executed by the Holder hereof or such Holder’s attorney duly authorized in
      writing, and thereupon one or more new Certificates of the same Class of
      authorized denominations evidencing the same initial Certificate Principal
      Amount (or Percentage Interest) will be issued to the designated transferee
      or
      transferees. As provided in the Trust Agreement and subject to certain
      limitations therein set forth, this Certificate is exchangeable for new
      Certificates of the same Class evidencing the same aggregate initial Certificate
      Principal Amount (or Percentage Interest) as requested by the Holder
      surrendering the same. No service charge will be made for any such registration
      of transfer or exchange, but the Certificate Registrar may require payment
      of a
      sum sufficient to cover any tax or other governmental charge payable in
      connection therewith.

     

    The
      Class
      A Certificates are issuable only in registered form, in minimum denominations
      of
      $25,000 in initial Certificate Principal Amount and in integral multiples of
      $1
      in excess thereof registered in the name of the nominee of the Clearing Agency,
      which shall maintain such Certificates through its book-entry facilities. The
      Class M1, Class M2, Class M3, Class M4, Class M5, Class M6, Class M7, Class
      M8,
      Class M9, Class B1 and Class B2 Certificates are issuable only in registered
      form, in denominations of $100,000 and in integral multiples of $1 in excess
      thereof registered in the name of the nominee of the Clearing Agency, which
      shall maintain such Certificates through its book-entry facilities. Each of
      the
      Class P and Class X Certificates are issuable in minimum denominations of 10%
      Percentage Interest and will be maintained in physical form. The Class LT-R
      and
      Class R Certificates will each be issued as a single Certificate and maintained
      in physical form. The Class R Certificates shall remain outstanding until the
      latest final Distribution Date for the Certificates (other than the Class LT-R
      Certificates), and the Class LT-R Certificates shall remain outstanding until
      the termination of the Trust Fund.

     

    The
      Certificates are subject to optional prepayment in full in accordance with
      the
      Trust Agreement on any Distribution Date after the date on which the Pool
      Balance is less than 10% of the sum of the Cut-off Date Balance, for an amount
      as specified in the Trust Agreement. In no event will the trust created by
      the
      Trust Agreement continue beyond the expiration of 21 years from the death of
      the
      last survivor of the descendants living at the date of the Trust Agreement
      of a
      certain person named in the Trust Agreement.

     

    
      
        
        

      

      
        A-7-2

        
          

        

      

      
        
        

      

    

     

    The
      Depositor, the Trustee and the Certificate Registrar and any agent of any of
      them may treat the Person in whose name this Certificate is registered as the
      owner hereof for all purposes, and neither the Depositor, the Trustee, nor
      the
      Certificate Registrar nor any such agent shall be affected by any notice to
      the
      contrary.

     

    As
      provided in the Trust Agreement, this Certificate and the Trust Agreement shall
      be construed in accordance with and governed by the laws of the State of New
      York, without regard to the conflict of laws provisions (other than Section
      5-1401 of the General Obligations Law) applied in the State of New York. In
      the
      event of any conflict between the provisions of this Certificate and the Trust
      Agreement, the Trust Agreement shall be controlling. Any term used herein and
      not otherwise defined shall be as defined in the Trust Agreement.

     

    
      
        
        

      

      
        A-7-3

        
          

        

      

      
        
        

      

    

     

    ASSIGNMENT

     

    

      
        	
                FOR
                  VALUE RECEIVED, the undersigned hereby sell(s) and assign(s) and
                  transfer(s) unto

              
	 
	 
	 
	 
	
                (Please
                  print or type name and address, including postal zip code, of assignee
                  and
                  social security number or employer identification
                  number)

              
	 
	 
	
                the
                  within Certificate stating in the names of the undersigned in the
                  Certificate Register and does hereby irrevocably constitute and
                  appoint

              
	 
	 
	
                to
                  transfer such Certificate in such Certificate Register of the
                  Trust.

              
	 
	
                I
                  [we] further direct the Certificate Registrar to issue a new Certificate
                  of the same Class of like principal to the above-named assignee
                  and
                  deliver such Certificate to the following address:

              
	 
	 
	 
	 
	 	 	 	 
	
                Dated:

              	 	 	 
	 	 	 	
                Signature
                  by or on behalf of Assignor

              
	 	 	 
	
                Authorized
                  Officer

              	 	
                Signature
                  Guaranteed

              
	 	 	 
	
                Name
                  of Institution

              	 	
                NOTICE:
                  The signature(s) of this assignment must correspond with the name(s)
                  on
                  the face of this Certificate without alteration or any change whatsoever.
                  The signature must be guaranteed by a participant in the Securities
                  Transfer Agents Medallion Program, the New York Stock Exchange
                  Medallion
                  Signature Program or the Stock Exchanges Medallion Program. Notarized
                  or
                  witnessed signatures are not acceptable as guaranteed
                  signatures.

              


      

    

    


    
      
        
          
          

        

        
          A-7-4

          
            

          

        

        
          
          

        

      

    

    


    DISTRIBUTION
      INSTRUCTIONS

     

    

      
        	
                The
                  assignee should include the following for the information of the
                  Certificate Registrar. Distributions shall be made by wire transfer
                  in
                  immediately available funds to

                ______________________________________________________________________________
                  for
                  the account of
                  _______________________________________________________________
                  account
                  number __________________ or, if mailed by check, to ____________________________________________________________________________
                  

                 

                Applicable
                  reports and statements should be mailed to
                  ________________________________________________________________________________________
                  

                 

                This
                  information is provided by _____________________________________________
                  the
                  assignee named above, or ____________________________________ as
                  its
                  agent. 

                 

              


      

      
        
          
          

        

        
          A-7-5

          
            

          

        

        
          
          

        

         

      

    

    EXHIBIT
      B-1

     

    FORM
      OF
      INITIAL CERTIFICATION

     

    
      	 
	
               Date

            


    

     

    Citibank,
      N.A.

    388
      Greenwich Street, 14th
      Floor


    New
      York,
      New York 10013

    Attention:
      Agency and Trust SASCO Series 2006-S4

    


    Aurora
      Loan Services, as Master Servicer

    327
      Inverness Drive South, Mail Stop 3195

    Englewood,
      Colorado 80112

    


    Structured
      Asset Securities Corporation,

    as
      Depositor

    745
      Seventh Avenue, 7th Floor

    New
      York,
      New York 10019

    


    
      	
            	Re:	
              Trust
                Agreement dated as of December 1,
                2006 (the “Trust Agreement”), by and among Structured Asset Securities
                Corporation, as Depositor, Aurora Loan Services LLC, as Master Servicer,
                Citibank, N.A., as Trustee and Clayton Fixed Income Services Inc.,
                as
                Credit Risk Manager with respect to Structured Asset Securities
                Corporation Mortgage Pass-Through Certificates, Series 2006-S4 

            


    

    


    Ladies
      and Gentlemen:

     

    In
      accordance with Section 2.02(a) of the Trust Agreement, subject to review of
      the
      contents thereof, the undersigned, as Custodian, hereby certifies that it has
      received the documents listed in Section 2.01(b) of the Trust Agreement for
      each
      Mortgage File pertaining to each Mortgage Loan listed on Schedule A, to the
      Trust Agreement, subject to any exceptions noted on Schedule I
      hereto.

     

    Capitalized
      words and phrases used herein and not otherwise defined herein shall have the
      respective meanings assigned to them in the Trust Agreement. This Certificate
      is
      subject in all respects to the terms of Section 2.02 of the Trust Agreement
      and
      the Trust Agreement sections cross-referenced therein.

     

    [Custodian]

    


    By:_____________________________________

    Name:
      

    Title:

    


    
      
        
        

      

      
        B-1-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      B-2

     

    FORM
      OF
      INTERIM CERTIFICATION

     

    
      
        	 
	
                 Date

              


      

    

     

    Citibank,
      N.A.

    388
      Greenwich Street, 14th
      Floor


    New
      York,
      New York 10013

    Attention:
      Agency and Trust SASCO Series 2006-S4

    


    Aurora
      Loan Services, as Master Servicer

    327
      Inverness Drive South, Mail Stop 3195

    Englewood,
      Colorado 80112

     

    Structured
      Asset Securities Corporation,

    as
      Depositor

    745
      Seventh Avenue, 7th Floor

    New
      York,
      New York 10019

     

    
      	
            	Re:	
              Trust
                Agreement dated as of December 1,
                2006 (the “Trust Agreement”), by and among Structured Asset Securities
                Corporation, as Depositor, Aurora Loan Services LLC, as Master Servicer,
                Citibank, N.A., as Trustee and Clayton Fixed Income Services Inc.,
                as
                Credit Risk Manager with respect to Structured Asset

              Securities
                Corporation Mortgage Pass-Through Certificates, Series 2006-S4 

            


    

     

    Ladies
      and Gentlemen:

     

    In
      accordance with Section 2.02(b) of the Trust Agreement, the undersigned, as
      Custodian, hereby certifies that as to each Mortgage Loan listed in the Mortgage
      Loan Schedule (other than any Mortgage Loan paid in full or listed on Schedule
      I
      hereto) it has received the applicable documents listed in Section 2.01(b)
      of
      the Trust Agreement.

     

    The
      undersigned hereby certifies that as to each Mortgage Loan identified on the
      Mortgage Loan Schedule, other than any Mortgage Loan listed on Schedule I
      hereto, it has reviewed the documents listed in Section 2.01(b) of the Trust
      Agreement and has determined that each such document appears regular on its
      face
      and appears to relate to the Mortgage Loan identified in such
      document.

     

    Capitalized
      words and phrases used herein shall have the respective meanings assigned to
      them in the Trust Agreement. This Certificate is qualified in all respects
      by
      the terms of said Trust Agreement including, but not limited to, Section
      2.02(b).

     

    
      
        
          
          

        

        
          B-2-1

          
            

          

        

        
          
          

        

      

    

    


    [Custodian]

    


    By:______________________________

    Name:
      

    Title:

     

    
      
        
        

      

      
        B-2-2

        
          

        

      

      
        
        

      

       

    

    EXHIBIT
      B-3

     

    FORM
      OF
      FINAL CERTIFICATION

    
       

      
        
          	 
	
                   Date

                


        

      

       
Citibank,
      N.A.

    388
      Greenwich Street, 14th
      Floor


    New
      York,
      New York 10013

    Attention:
      Agency and Trust SASCO Series 2006-S4

    


    Aurora
      Loan Services, as Master Servicer

    327
      Inverness Drive South, Mail Stop 3195

    Englewood,
      Colorado 80112

     

    Structured
      Asset Securities Corporation,

    as
      Depositor

    745
      Seventh Avenue, 7th Floor

    New
      York,
      New York 10019

    


    
      	
            	Re:	
              Trust
                Agreement dated as of December 1,
                2006 (the “Trust Agreement”), by and among Structured Asset Securities
                Corporation, as Depositor, Aurora Loan Services LLC, as Master Servicer,
                Citibank, N.A., as Trustee and Clayton Fixed Income Services Inc.,
                as
                Credit Risk Manager with respect to Structured Asset

              Securities
                Corporation Mortgage Pass-Through Certificates, Series 2006-S4 

            


    

    


    Ladies
      and Gentlemen:

     

    In
      accordance with Section 2.02(d) of the Trust Agreement, the undersigned, as
      Custodian on behalf of the Trustee, hereby certifies that as to each Mortgage
      Loan listed in the Mortgage Loan Schedule (other than any Mortgage Loan paid
      in
      full or listed on Schedule I hereto) it has received the applicable documents
      listed in Section 2.01(b) of the Trust Agreement.

     

    The
      undersigned hereby certifies that as to each Mortgage Loan identified in the
      Mortgage Loan Schedule, other than any Mortgage Loan listed on Schedule I
      hereto, it has reviewed the documents listed in Section 2.01(b) of the Trust
      Agreement and has determined that each such document appears to be complete
      and,
      based on an examination of such documents, the information set forth in items
      (i) through (vi) of the definition of Mortgage Loan Schedule is
      correct.

     

    Capitalized
      words and phrases used herein shall have the respective meanings assigned to
      them in the Trust Agreement. This Certificate is qualified in all respects by
      the terms of said Trust Agreement.

     

    


    
      
        
          
          

        

        
          B-3-1

          
            

          

        

        
          
          

        

      

    

    


    [Custodian]

    


    By:_____________________________________

    Name:

    Title:
      

    


    
      
        
        

      

      
        B-3-2

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      B-4

     

    FORM
      OF
      ENDORSEMENT

     

    Pay
      to
      the order of Citibank, N.A., as Trustee (the “Trustee”),
      under a Trust Agreement dated as of December 1, 2006, among Structured
      Asset Securities Corporation, as depositor, Aurora Loan Services LLC, as master
      servicer, Clayton Fixed Income Services Inc., as credit risk manager, and the
      Trustee, relating to Structured Asset Securities Corporation Mortgage
      Pass-Through Certificates, Series 2006-S4, without recourse. 

     

    


     

    __________________________________

    [current
      signatory on note]

     

    By:_______________________________

    Name:

    Title:

    


    
      
        
        

      

      
        B-4-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      C

     

    REQUEST
      FOR RELEASE OF DOCUMENTS AND RECEIPT

    
       

      
        
          	 
	
                   Date

                


        

      

       

    

    [Addressed
      to Trustee

    or,
      if
      applicable, Custodian]

     

    In
      connection with the administration of the mortgages held by you as Trustee
      under
      a certain Trust Agreement dated as of December 1,
      2006, by and among Structured Asset Securities Corporation, as Depositor,
      Citibank, N.A., as Trustee, Aurora Loan Services LLC, as Master Servicer and
      Clayton Fixed Income Services Inc., as Credit Risk Manager (the “Trust
      Agreement”), the undersigned Servicer hereby requests a release of the Mortgage
      File held by you as Trustee with respect to the following described Mortgage
      Loan for the reason indicated below.

     

    Mortgagor’s
      Name:

     

    Address:

     

    Loan
      No.:

     

    Reason
      for requesting file:

     

    1. Mortgage
      Loan paid in full. (The Servicer hereby certifies that all amounts received
      in
      connection with the loan have been or will be credited to the Certificate
      Account pursuant to the Trust Agreement.)

     

    2. The
      Mortgage Loan is being foreclosed.

     

    3. Mortgage
      Loan substituted. (The Servicer hereby certifies that a Qualifying Substitute
      Mortgage Loan has been assigned and delivered to you along with the related
      Mortgage File pursuant to the Trust Agreement.)

     

    4. Mortgage
      Loan repurchased. (The Servicer hereby certifies that the Purchase Price has
      been credited to the Certificate Account pursuant to the Trust
      Agreement.)

     

    5. Other.
      (Describe)

     

    The
      undersigned acknowledges that the above Mortgage File will be held by the
      undersigned in accordance with the provisions of the Trust Agreement and will
      be
      returned to you within ten (10) days of our receipt of the Mortgage File, except
      if the Mortgage Loan has been paid in full, or repurchased or substituted for
      a
      Qualifying Substitute Mortgage Loan (in which case the Mortgage File will be
      retained by us permanently) and except if the Mortgage Loan is being foreclosed
      (in which case the Mortgage File will be returned when no longer required by
      us
      for such purpose).

     

    
      
        
        

      

      
        C-1

        
          

        

      

      
        
        

      

    

     

    Capitalized
      terms used herein shall have the meanings ascribed to them in the Trust
      Agreement.

     

    _____________________________________

    [Name
      of
      Servicer]

     

    By:__________________________________

    Name:

    Title:
      Servicing Officer

    


    
      
        
        

      

      
        C-2

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      D-1

     

    FORM
      OF
      RESIDUAL CERTIFICATE TRANSFER AFFIDAVIT (TRANSFEREE)

     

    

      
        	
                STATE
                  OF

              	
                )

              
	 	
                )
                  ss.:

              
	
                COUNTY
                  OF

              	
                )

              


      

    

     

    [NAME
      OF
      OFFICER], _________________ being first duly sworn, deposes and
      says:

     

    
      	 	
              1.

            	
              That
                he [she] is [title of officer] ________________________ of [name
                of
                Purchaser] _________________________________________ (the “Purchaser”),
                a _______________________ [description of type of entity] duly organized
                and existing under the laws of the [State of __________] [United
                States],
                on behalf of which he [she] makes this
                affidavit.

            


    

     

    
      	 	
              2.

            	
              That
                the Purchaser’s Taxpayer Identification Number is
                [           ].

            


    

     

    
      	 	
              3.

            	
              That
                the Purchaser is not a “disqualified organization” within the meaning of
                Section 860E(e)(5) of the Internal Revenue Code of 1986, as amended
                (the
                “Code”) and will not be a “disqualified organization” as of [date of
                transfer], and that the Purchaser is not acquiring a Residual Certificate
                (as defined in the Agreement) for the account of, or as agent (including
                a
                broker, nominee, or other middleman) for, any person or entity from
                which
                it has not received an affidavit substantially in the form of this
                affidavit. For these purposes, a “disqualified organization” means the
                United States, any state or political subdivision thereof, any foreign
                government, any international organization, any agency or instrumentality
                of any of the foregoing (other than an instrumentality if all of
                its
                activities are subject to tax and a majority of its board of directors
                is
                not selected by such governmental entity), any cooperative organization
                furnishing electric energy or providing telephone service to persons
                in
                rural areas as described in Code Section 1381(a)(2)(C), any “electing
                large partnership” within the meaning of Section 775 of the Code, or any
                organization (other than a farmers’ cooperative described in Code Section
                521) that is exempt from federal income tax unless such organization
                is
                subject to the tax on unrelated business income imposed by Code Section
                511.

            


    

     

    
      	 	
              4.

            	
              That
                the Purchaser (x) is not, and on __________________ [date of transfer]
                will not be, an employee benefit plan or other retirement arrangement
                subject to Section 406 of the Employee Retirement Income Security
                Act of
                1974, as amended (“ERISA”), or Section 4975 of the Code (collectively, a
                “Plan”) or a person acting on behalf of any such Plan or investing the
                assets of any such Plan to acquire a Residual Certificate; (y) if
                the
                Residual Certificate has been the subject of an ERISA-Qualifying
                Underwriting, is an insurance company that is purchasing the Residual
                Certificate with funds contained in an “insurance company general account”
                as defined in Section V(e) of Prohibited Transaction Class Exemption
                (“PTCE”) 95-60 and the purchase and holding of the Residual Certificate
                are covered under Sections I and III of PTCE 95-60; or (z) herewith
                delivers to the Trustee an opinion of counsel (a “Benefit Plan Opinion”)
                satisfactory to the Trustee, and upon which the Trustee, the Master
                Servicer and the Depositor shall be entitled to rely, to the effect
                that
                the purchase or holding of such Residual Certificate by the Investor
                will
                not result in any non-exempt prohibited transactions under Title
                I of
                ERISA or Section 4975 of the Code and will not subject the Trustee,
                the
                Master Servicer or the Depositor to any obligation in addition to
                those
                undertaken by such entities in the Trust Agreement, which opinion
                of
                counsel shall not be an expense of the Trust Fund or any of the above
                parties.

            


    

     

    
      
        
        

      

      
        D-1-1

        
          

        

      

      
        
        

      

    

     

    
      	 	
              5.

            	
              That
                the Purchaser hereby acknowledges that under the terms of the Trust
                Agreement (the “Agreement”) by and among Structured Asset Securities
                Corporation, as Depositor, Aurora Loan Services LLC, as Master Servicer,
                Clayton Fixed Income Services Inc., as Credit Risk Manager, and Citibank,
                N.A., as Trustee, dated as of December 1, 2006, relating to
                Structured Asset Securities Corporation Mortgage Pass-Through
                Certificates, Series 2006-S4, no transfer of the Residual Certificate
                shall be permitted to be made to any person unless the Depositor
                and
                Trustee have received a certificate from such transferee containing
                the
                representations in paragraphs 3 and 4
                hereof.

            


    

     

    
      	 	
              6.

            	
              That
                the Purchaser does not hold REMIC residual securities as nominee
                to
                facilitate the clearance and settlement of such securities through
                electronic book-entry changes in accounts of participating organizations
                (such entity, a “Book-Entry
                Nominee”).

            


    

     

    
      	 	
              7.

            	
              That
                the Purchaser does not have the intention to impede the assessment
                or
                collection of any federal, state or local taxes legally required
                to be
                paid with respect to such Residual
                Certificate.

            


    

     

    
      	 	
              8.

            	
              That
                the Purchaser will not transfer a Residual Certificate to any person
                or
                entity (i) as to which the Purchaser has actual knowledge that the
                requirements set forth in paragraph 3, paragraph 6 or paragraph 10
                hereof
                are not satisfied or that the Purchaser has reason to believe does
                not
                satisfy the requirements set forth in paragraph 7 hereof, and (ii)
                without
                obtaining from the prospective Purchaser an affidavit substantially
                in
                this form and providing to the Trustee a written statement substantially
                in the form of Exhibit D-2 to the
                Agreement.

            


    

     

    
      	 	
              9.

            	
              That
                the Purchaser understands that, as the holder of a Residual Certificate,
                the Purchaser may incur tax liabilities in excess of any cash flows
                generated by the interest and that it intends to pay taxes associated
                with
                holding such Residual Certificate as they become
                due.

            


    

     

    
      	 	
              10.

            	
              That
                the Purchaser (i) is not a Non-U.S. Person or (ii) is a Non-U.S.
                Person
                that holds a Residual Certificate in connection with the conduct
                of a
                trade or business within the United States and has furnished the
                transferor and the Trustee with an effective Internal Revenue Service
                Form
                W-8ECI (Certificate of Foreign Person’s Claim for Exemption From
                Withholding on Income Effectively Connected With the Conduct of a
                Trade or
                Business in the United States) or successor form at the time and
                in the
                manner required by the Code or (iii) is a Non-U.S. Person that has
                delivered to both the transferor and the Trustee an opinion of a
                nationally recognized tax counsel to the effect that the transfer
                of such
                Residual Certificate to it is in accordance with the requirements
                of the
                Code and the regulations promulgated thereunder and that such transfer
                of
                a Residual Certificate will not be disregarded for federal income
                tax
                purposes. “Non-U.S. Person” means any person other than a “United States
                person” within the meaning of Section 7701(a)(30) of the
                Code.

            


    

     

    
      
        
        

      

      
        D-1-2

        
          

        

      

      
        
        

      

    

     

    
      	 	
              11.

            	
              That
                the Purchaser agrees to such amendments of the Trust Agreement as
                may be
                required to further effectuate the restrictions on transfer of any
                Residual Certificate to such a “disqualified organization,” an agent
                thereof, a Book-Entry Nominee, or a person that does not satisfy
                the
                requirements of paragraph 7 and paragraph 10
                hereof.

            


    

     

    
      	 	
              12.

            	
              That
                the Purchaser consents to the designation of the Trustee as its agent
                to
                act as “tax matters person” of the Trust Fund pursuant to the Trust
                Agreement.

            


    

     

    IN
      WITNESS WHEREOF, the Purchaser has caused this instrument to be executed on
      its
      behalf, pursuant to authority of its Board of Directors, by its [title of
      officer] this _____ day of __________, 20__.

     

    _________________________________

    [name
      of
      Purchaser]

     

    By:______________________________

    Name:
      

    Title:
      

     

    Personally
      appeared before me the above-named [name of officer] ________________, known
      or
      proved to me to be the same person who executed the foregoing instrument and
      to
      be the [title of officer] _________________ of the Purchaser, and acknowledged
      to me that he [she] executed the same as his [her] free act and deed and the
      free act and deed of the Purchaser.

     

    Subscribed
      and sworn before me this _____ day of __________, 20__.

     

    NOTARY
      PUBLIC

     

    ______________________________

     

    COUNTY
      OF_____________________

     

    
      
         

      

      
        D-1-3

        
          

        

      

      
         

      

    

    STATE
      OF______________________

     

    My
      commission expires the _____ day of __________, 20__.

     

    
      
        
        

      

      
        D-1-4

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      D-2

     

    FORM
      OF
      RESIDUAL CERTIFICATE TRANSFER AFFIDAVIT (TRANSFEROR)

    
      
         

        
          
            	 
	
                     Date

                  


          

        

         

      

    

    
      	
            	Re:	
              Structured
                Asset Securities Corporation

              Mortgage
                Pass-Through Certificates, Series
                2006-S4

            


    

     

     

    _______________________
      (the “Transferor”)
      has reviewed the attached affidavit of _____________________________ (the
“Transferee”), and has no actual knowledge that such affidavit is not true and
      has no reason to believe that the information contained in paragraph 7 thereof
      is not true, and has no reason to believe that the Transferee has the intention
      to impede the assessment or collection of any federal, state or local taxes
      legally required to be paid with respect to a Residual Certificate. In addition,
      the Transferor has conducted a reasonable investigation at the time of the
      transfer and found that the Transferee had historically paid its debts as they
      came due and found no significant evidence to indicate that the Transferee
      will
      not continue to pay its debts as they become due.

     

    Very
      truly yours,

     

    _______________________________

    Name:

    Title:

    


    


    
      
        
        

      

      
        D-2-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      E

     

    SERVICING
      AGREEMENTS

    


    LIST
      OF
      SERVICING AGREEMENTS

    


    


    


    
      	 	
              1.

            	
              Securitization
                Servicing Agreement dated as of December 1, 2006, among Aurora Loan
                Services LLC, as servicer and as master servicer (in such capacity,
                the
                “Master Servicer”) and Lehman Brothers Holdings Inc., as seller (the
                “Seller”).

            


    

    


    


    
      
        
        

      

      
        E-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      F

     

    FORM
      OF
      RULE 144A TRANSFER CERTIFICATE

     

    
      	
            	Re:	
              Structured
                Asset Securities Corporation 
                Mortgage
                  Pass-Through Certificates

                Series
                  2006-S4   

              

            


    

    
    

     

    Reference
      is hereby made to the Trust Agreement dated as of December 1,
      2006 (the “Trust Agreement”), by and among Structured Asset Securities
      Corporation, as Depositor, Aurora Loan Services LLC, as Master Servicer, Clayton
      Fixed Income Services Inc., as Credit Risk Manager, and Citibank, N.A., as
      Trustee. Capitalized terms used but not defined herein shall have the meanings
      given to them in the Trust Agreement.

     

    This
      letter relates to $__________ initial Certificate Balance of Class     
      Certificates
      which are held in the form of Definitive Certificates registered in the name
      of
                                
      (the
“Transferor”). The Transferor has requested a transfer of such Definitive
      Certificates for Definitive Certificates of such Class registered in the name
      of
      [insert name of transferee].

     

    In
      connection with such request, and in respect of such Certificates, the
      Transferor hereby certifies that such Certificates are being transferred in
      accordance with (i) the transfer restrictions set forth in the Trust Agreement
      and the Certificates and (ii) Rule 144A under the Securities Act to a purchaser
      that the Transferor reasonably believes is a “qualified institutional buyer”
within the meaning of Rule 144A purchasing for its own account or for the
      account of a “qualified institutional buyer,” which purchaser is aware that the
      sale to it is being made in reliance upon Rule 144A, in a transaction meeting
      the requirements of Rule 144A and in accordance with any applicable securities
      laws of any state of the United States or any other applicable
      jurisdiction.

     

    This
      certificate and the statements contained herein are made for your benefit and
      the benefit of the Depositor.

     

    _____________________________________

    [Name
      of
      Transferor]

     

    By:__________________________________

    Name:

    Title:

     

    Dated:
      ___________, ____

    


    
      
        
        

      

      
        F-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      G

     

    FORM
      OF
      PURCHASER’S LETTER FOR

    INSTITUTIONAL
      ACCREDITED INVESTOR

    
      
         

        
          
            	 
	
                     Date

                  


          

        

         

      
Citibank,
      N.A.

    111
      Wall
      Street

    New
      York,
      New York 10005

    Attention:
      15th
      Floor
      Window

    


    Structured
      Asset Securities Corporation,

    as
      Depositor

    745
      Seventh Avenue, 7th Floor

    New
      York,
      New York 10019

    


    
      	
            	Re:	
              Structured
                Asset Securities Corporation Mortgage Pass-Through Certificates,
                Series
                2006-S4

            


    

    


    Dear
      Sirs:

     

    In
      connection with our proposed purchase of $______________ principal amount of
      Structured Asset Securities Corporation Mortgage Pass-Through Certificates,
      Series 2006-S4 (the “Privately Offered Certificates”) of the Structured Asset
      Securities Corporation (the “Depositor”), we confirm that:

     

    
      	
              (1)

            	
              We
                understand that the Privately Offered Certificates have not been,
                and will
                not be, registered under the Securities Act of 1933, as amended (the
                “Securities Act”), and may not be sold except as permitted in the
                following sentence. We agree, on our own behalf and on behalf of
                any
                accounts for which we are acting as hereinafter stated, that if we
                should
                sell any Privately Offered Certificates within two years of the later
                of
                the date of original issuance of the Privately Offered Certificates
                or the
                last day on which such Privately Offered Certificates are owned by
                the
                Depositor or any affiliate of the Depositor we will do so only (A)
                to the
                Depositor, (B) to “qualified institutional buyers” (within the meaning of
                Rule 144A under the Securities Act) in accordance with Rule 144A
                under the
                Securities Act (“QIBs”), (C) pursuant to the exemption from registration
                provided by Rule 144 under the Securities Act, or (D) to an institutional
                “accredited investor” within the meaning of Rule 501(a)(1), (2), (3) or
                (7) of Regulation D under the Securities Act that is not a QIB (an
                “Institutional Accredited Investor”) which, prior to such transfer,
                delivers to the Trustee under the Trust Agreement dated as of
                December 1, 2006, by and among the Depositor, Aurora Loan Services
                LLC, as Master Servicer, Clayton Fixed Income Services Inc., as Credit
                Risk Manager, and Citibank, N.A., as Trustee (the “Trustee”), a signed
                letter in the form of this letter; and we further agree, in the capacities
                stated above, to provide to any person purchasing any of the Privately
                Offered Certificates from us a notice advising such purchaser that
                resales
                of the Privately Offered Certificates are restricted as stated
                herein.

            


    

     

    
      
        
        

      

      
        G-1

        
          

        

      

      
        
        

      

    

     

    
      	
              (2)

            	
              We
                understand that, in connection with any proposed resale of any Privately
                Offered Certificates to an Institutional Accredited Investor, we
                will be
                required to furnish to the Trustee and the Depositor a certification
                from
                such transferee in the form hereof to confirm that the proposed sale
                is
                being made pursuant to an exemption from, or in a transaction not
                subject
                to, the registration requirements of the Securities Act. We further
                understand that the Privately Offered Certificates purchased by us
                will
                bear a legend to the foregoing
                effect.

            


    

     

    
      	
              (3)

            	
              We
                are acquiring the Privately Offered Certificates for investment purposes
                and not with a view to, or for offer or sale in connection with,
                any
                distribution in violation of the Securities Act. We have such knowledge
                and experience in financial and business matters as to be capable
                of
                evaluating the merits and risks of our investment in the Privately
                Offered
                Certificates, and we and any account for which we are acting are
                each able
                to bear the economic risk of such
                investment.

            


    

     

    
      	
              (4)

            	
              We
                are an Institutional Accredited Investor and we are acquiring the
                Privately Offered Certificates purchased by us for our own account
                or for
                one or more accounts (each of which is an Institutional Accredited
                Investor) as to each of which we exercise sole investment
                discretion.

            


    

     

    
      	(5)    	
              We
                have received such information as we deem necessary in order to make
                our
                investment decision.

            


    

     

    
      	(6)    	
              If
                we are acquiring ERISA-Restricted Certificates, we understand that
                in
                accordance with ERISA, the Code and the Exemption, no Plan and no
                person
                acting on behalf of such a Plan may acquire such Certificate except
                in
                accordance with Section 3.03(d) of the Trust
                Agreement.

            


    

     

    Terms
      used in this letter which are not otherwise defined herein have the respective
      meanings assigned thereto in the Trust Agreement.

     

    
      
        
          
          

        

        
          G-2

          
            

          

        

        
          
          

        

      

    

    


    You
      and
      the Depositor are entitled to rely upon this letter and are irrevocably
      authorized to produce this letter or a copy hereof to any interested party
      in
      any administrative or legal proceeding or official inquiry with respect to
      the
      matters covered hereby.

     

    Very
      truly yours,

     

    __________________________________

    [Purchaser]

     

    By:
      ________________________________

    Name:

    Title:

     

    


    
      
        
        

      

      
        G-3

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      H

     

    FORM
      OF
      ERISA TRANSFER AFFIDAVIT

     

    
      
        	
                STATE
                  OF

              	
                )

              
	 	
                )
                  ss.:

              
	
                COUNTY
                  OF

              	
                )

              


      

       

    

    The
      undersigned, being first duly sworn, deposes and says as follows:

     

    1. The
      undersigned is the ______________________ of (the “Investor”),
      a [corporation duly organized] and existing under the laws of __________, on
      behalf of which he makes this affidavit.

     

    2. In
      the
      case of an ERISA-Restricted Certificate, the Investor (x) is not, and on
      ___________ [date of transfer] will not be, an employee benefit plan or other
      retirement arrangement subject to Section 406 of the Employee Retirement Income
      Security Act of 1974, as amended (“ERISA”), or Section 4975 of the Internal
      Revenue Code of 1986, as amended (the “Code”) (collectively, a “Plan”) or a
      person acting on behalf of any such Plan or investing the assets of any such
      Plan to acquire a Certificate; (y) if the Certificate has been the subject
      of an
      ERISA-Qualifying Underwriting, is an insurance company that is purchasing the
      Certificate with funds contained in an “insurance company general account” as
      defined in Section V(e) of Prohibited Transaction Class Exemption (“PTCE”) 95-60
      and the purchase and holding of the Certificate are covered under Sections
      I and
      III of PTCE 95-60; or (z) herewith delivers to the Trustee an opinion of counsel
      (a “Benefit Plan Opinion”) satisfactory to the Trustee, and upon which the
      Trustee, the Master Servicer and the Depositor shall be entitled to rely, to
      the
      effect that the purchase or holding of such Certificate by the Investor will
      not
      result in any non-exempt prohibited transactions under Title I of ERISA or
      Section 4975 of the Code and will not subject the Trustee, the Master Servicer
      or the Depositor to any obligation in addition to those undertaken by such
      entities in the Trust Agreement, which opinion of counsel shall not be an
      expense of the Trust Fund or any of the above parties.

     

    3. In
      the
      case of an ERISA-Restricted Swap Certificate, prior to the termination of the
      Swap Agreement, either (i) the Investor is neither a Plan nor a person acting
      on
      behalf of any such Plan or using the assets of any such Plan to effect such
      transfer or (ii) the acquisition and holding of the ERISA-Restricted Swap
      Certificate are eligible for exemptive relief under PTCE 84-14, PTCE 90-1,
      PTCE
      91-38, PTCE 95-60 or PTCE 96-23.

     

    
      
         

      

      
        H-1

        
          

        

      

      
         

      

    

    4. The
      Investor hereby acknowledges that under the terms of the Trust Agreement (the
      “Agreement”) by and among Structured Asset Securities Corporation, as Depositor,
      Aurora Loan Services LLC, as Master Servicer, Clayton Fixed Income Services
      Inc., as Credit Risk Manager, and Citibank, N.A., as Trustee, dated as of
      December 1, 2006, regarding Structured Asset Securities Corporation
      Mortgage Pass-Through Certificates, Series 2006-S4, no transfer of the
      ERISA-Restricted Certificates or the ERISA-Restricted Swap Certificates shall
      be
      permitted to be made to any person unless the Depositor and Trustee have
      received a certificate from such transferee in the form hereof.

     

    


    
      
        
          
          

        

        
          H-2

          
            

          

        

        
          
          

        

      

    

    


    IN
      WITNESS WHEREOF, the Investor has caused this instrument to be executed on
      its
      behalf, pursuant to proper authority, by its duly authorized officer, duly
      attested, this ____ day of _______________, 20___.

     

    _________________________________

    [Investor]

     

    By:______________________________

    Name:

    Title:

     

    ATTEST:

     

    


     

    _________________________

     

    STATE
      OF               
      )

    )
      ss:

    COUNTY
      OF            )

     

    Personally
      appeared before me the above-named ________________, known or proved to me
      to be
      the same person who executed the foregoing instrument and to be the
      ____________________ of the Investor, and acknowledged that he executed the
      same
      as his free act and deed and the free act and deed of the Investor.

     

    Subscribed
      and sworn before me this _____ day of _________ 20___.

     

    ______________________________

    NOTARY
      PUBLIC

     

    My
      commission expires the

    _____
      day
      of __________, 20___.

     

    


    
      
        
        

      

      
        H-3

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      I

     

    [Reserved]

     

    


    
      
        
        

      

      
        I-1

        
          

        

      

      
        
        

      

    

    
 

    EXHIBIT
      J

     

    [Reserved]

     

    


    
      
        
        

      

      
        J-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      K

     

    LIST
      OF
      CUSTODIAL AGREEMENTS

     

    
      	 	
              1.

            	
              Custodial
                Agreement dated as of December 1, 2006, between LaSalle Bank National
                Association, as Custodian and the
                Trustee.

            


    

     

    
      	 	
              2.

            	
              Custodial
                Agreement dated as of December 1, 2006, between U.S. Bank National
                Association, as Custodian and the
                Trustee.

            


    

     

    


    
      
        
        

      

      
        K-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      L

     

    LIST
      OF
      CREDIT RISK MANAGEMENT AGREEMENTS

     

    


     

    
      	 	
              1.

            	
              Credit
                Risk Management Agreement dated December 28, 2006, between Clayton
                Fixed Income Services Inc., as credit risk manager (the “Credit Risk
                Manager”) and Aurora Loan Services LLC, as
                servicer.

            


    

     

    
      
        
        

      

      
        L-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      M

     

    FORM
      OF
      BACK-UP CERTIFICATION TO BE PROVIDED TO

    THE
      DEPOSITOR AND/OR THE MASTER SERVICER BY THE TRUSTEE

    


    Structured
      Asset Securities Corporation

    745
      Seventh Avenue, 7th Floor

    New
      York,
      New York 10019

    Attention:
      Mortgage Finance, SASCO 2006-S4

    


    Aurora
      Loan Services LLC

    327
      Inverness Drive South

    Englewood,
      Colorado 80112

    


    
      	
            	Re:	
              Structured
                Asset Securities Corporation

              Mortgage
                Pass-Through Certificates, Series
                2006-S4

            


    

     

    Reference
      is made to the Trust Agreement dated as of December 1, 2006 (the “Trust
      Agreement”), by and among Citibank, N.A. (the “Trustee”), Aurora Loan Services
      LLC, as master servicer (the “Master Servicer”), Structured Asset Securities
      Corporation, as depositor (the “Depositor”), and Clayton Fixed Income Services
      Inc., as credit risk manager. The Trustee hereby certifies to the Depositor
      and
      the Master Servicer, and their respective officers, directors and affiliates,
      and with the knowledge and intent that they will rely upon this certification,
      that:

    


    
      	 	
              (i)
                

            	
              The
                Trustee has reviewed the annual report on Form 10-K for the fiscal
                year [
                ], and all reports on Form 10-D containing distribution reports filed
                in
                respect of periods included in the year covered by that annual report,
                relating to the above-referenced
                trust;

            


    

    


    
      	 	
              (ii)
                

            	
              Based
                solely upon the information provided to us pursuant to Sections 6.20(d)
                and 6.20(e) and the information provided by us pursuant to Sections
                6.20(d) and 6.20(e), the information set forth in the reports referenced
                in (i) above does not contain any untrue statement of material fact;
                and

            


    

    


    
      	 	
              (iii)
                

            	
              Based
                on my knowledge, the distribution information required to be provided
                by
                the Trustee under the Trust Agreement, together with the information
                specific to and required to be provided by the Trustee pursuant to
                Sections 6.20(d) and 6.20(e) is included in these
                reports.

            


    

    


    Date:

    CITIBANK,
      N.A., as Trustee

    


    By: ____________________________

    Name: __________________________

    Title: ___________________________

    


    
      
        
        

      

      
        M-1

        
          

        

      

      
        
        

      

    

    


    EXHIBIT
      N-1

    


    FORM
      OF
      TRANSFER CERTIFICATE

    FOR
      TRANSFER FROM RESTRICTED GLOBAL SECURITY

    TO
      REGULATION S GLOBAL SECURITY

    (Transfers
      pursuant to Sec. 3.03(g)(B)

                          
      of the
      Agreement)                            

     

    
      	
            	Re:	
              Structured
                Asset Securities Corporation
Mortgage Pass-Through Certificates
                Series 2006-S4

            


    

     

    Reference
      is hereby made to the Trust Agreement (the “Agreement”)
      by and among Structured Asset Securities Corporation, as Depositor, Aurora
      Loan
      Services LLC, as Master Servicer, Clayton Fixed Income Services Inc., as Credit
      Risk Manager and Citibank, N.A., as Trustee, dated as of December 1, 2006.
      Capitalized terms used but not defined herein shall have the meanings given
      to
      them in the Agreement.

     

    This
      letter relates to U.S. $                            
      aggregate
      principal amount of Securities which are held in the form of a Restricted Global
      Security with DTC in the name of [name of transferor]                                                       
      (the
“Transferor”) to effect the transfer of the Securities in exchange for an
      equivalent beneficial interest in a Regulation S Global Security.

     

    In
      connection with such request, the Transferor does hereby certify that such
      transfer has been effected in accordance with the transfer restrictions set
      forth in the Agreement and the Securities and in accordance with Rule 904 of
      Regulation S, and that:

     

    a. the
      offer
      of the Securities was not made to a person in the United States; 

     

    b. at
      the
      time the buy order was originated, the transferee was outside the United States
      or the Transferor and any person acting on its behalf reasonably believed that
      the transferee was outside the United States;

     

    c. no
      directed selling efforts have been made in contravention of the requirements
      of
      Rule 903 or 904 of Regulation S, as applicable;

     

    d. the
      transaction is not part of a plan or scheme to evade the registration
      requirements of the United States Securities Act of 1933, as amended;
      and

     

    
      
        e.
          the
          transferee is not a U.S. person (as defined in Regulation
          S).

      

    

     

    


    
      
        
          
          

        

        
          N-1-1

          
            

          

        

        
          
          

        

      

    

    


    You
      are
      entitled to rely upon this letter and are irrevocably authorized to produce
      this
      letter or a copy hereof to any interested party in any administrative or legal
      proceedings or official inquiry with respect to the matters covered hereby.
      Terms used in this certificate have the meanings set forth in Regulation
      S.

     

    


                                                                
      

    [Name
      of
      Transferor]

    


    


    By:
                                                              

    Name:

           
      Title:

     

    Date:             
        ,
             

    


    


    
      
        
        

      

      
        N-1-2

        
          

        

      

      
        
        

      

    

    


    EXHIBIT
      N-2

    


    FORM
      OF
      TRANSFER CERTIFICATE FOR TRANSFER 

    FROM
      REGULATION S GLOBAL SECURITY

    TO
      RESTRICTED GLOBAL SECURITY

    (Transfers
      pursuant to Sec. 3.03(g)(C)

                              of
      the
      Agreement)                          

     

    
      	
            	Re:	
              Structured
                Asset Securities Corporation
Mortgage Pass-Through Certificates
                Series 2006-S4

            


    

     

    Reference
      is hereby made to the Trust Agreement (the “Agreement”)
      by and among Structured Asset Securities Corporation, as Depositor, Aurora
      Loan
      Services LLC, as Master Servicer, Clayton Fixed Income Services Inc., as Credit
      Risk Manager, Citibank, N.A., as Trustee, dated as of December 1, 2006.
      Capitalized terms used but not defined herein shall have the meanings given
      to
      them in the Agreement.

     

    This
      letter relates to U.S. $                            
      aggregate
      principal amount of Securities which are held in the form of a Regulations
      S
      Global Security in the name of [name of transferor]                                                       
      (the
      “Transferor”) to effect the transfer of the Securities in exchange for an
      equivalent beneficial interest in a Restricted Global Security.

     

    In
      connection with such request, and in respect of such Securities, the Transferor
      does hereby certify that such Securities are being transferred in accordance
      with (i) the transfer restrictions set forth in the Agreement and the Securities
      and (ii) Rule 144A under the United States Securities Act of 1933, as amended,
      to a transferee that the Transferor reasonably believes is purchasing the
      Securities for its own account or an account with respect to which the
      transferee exercises sole investment discretion, the transferee and any such
      account is a qualified institutional buyer within the meaning of Rule 144A,
      in a
      transaction meeting the requirements of Rule 144A and in accordance with any
      applicable securities laws of any state of the United States or any other
      jurisdiction.

     

                                                                
      

    [Name
      of
      Transferor]

    


    By:                                                        

    Name:

    Title:

     

    Date:             
        ,
             

    


    


    
      
        
        

      

      
        N-2-1

        
          

        

      

      
        
        

      

    

    
EXHIBIT
      O

     

    [Reserved]

     

    


     

    
      
        
        

      

      
        O-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      P

     

    SWAP
      AGREEMENT

     

    See
      closing book or exhibit to Form 8-K filed 

    with
      the
      SEC under SASCO
      2006-S4

     

    


    
      
        
        

      

      
        P-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      Q

    


    [Reserved]

    
 

    
      
        
        

      

      
        Q-1

        
          

        

      

      
        
        

      

    

    


    EXHIBIT
      R

    


    [Reserved]

    


    


     

    
      
        
        

      

      
        R-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      S-1

    


    FORM
      OF
      WATCHLIST REPORT

    


    
      
        
        

      

      
        S-1-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      S-2

    


    FORM
      OF
      LOSS SEVERITY REPORT

    


     

    
      
        
        

      

      
        S-2-1

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      S-3

    


    FORM
      OF
      PREPAYMENT PREMIUMS REPORT

    


    
      
        
        

      

      
        S-3-1

        
          

        

      

      
        
        

      

    

    


    EXHIBIT
      S-4

    


    FORM
      OF
      ANALYTICS REPORT

    


    
      
        
        

      

      
        S-4-1

        
          

        

      

      
        
        

      

       

    

    EXHIBIT
      T

    


    SERVICING
      CRITERIA TO BE ADDRESSED IN 

    REPORT
      ON
      ASSESSMENT OF COMPLIANCE

    


    Where
      there are multiple checks for criteria the attesting party will identify in
      their management assertion that they are attesting only to the portion of the
      distribution chain they are responsible for in the related transaction
      agreements. Capitalized terms used herein but not defined herein shall have
      the
      meanings assigned to them in the Trust Agreement dated as of December 1,
      2006 (the “Trust Agreement”), by and among Structured Asset Securities
      Corporation, as depositor (the “Depositor”), Citibank, N.A., (the “Trustee”),
      Aurora Loan Services LLC, as master servicer (the “Master Servicer”), and
      Clayton Fixed Income Services Inc., as credit risk manager (the “Credit Risk
      Manager”). 

    


    


    
      	
              Regulation
                AB

              Reference

            	
              Servicing
                Criteria

            	
              Credit
                Risk Manager

            	
              Trustee

            	
              Master
                Servicer

            
	 	
              General Servicing
                 Considerations

            	 	 	 
	
              1122(d)(1)(i)

            	
              Policies
                and procedures are instituted to monitor any performance or other
                triggers
                and events of default in accordance with the transaction
                agreements.

            	 	 	
              X

            
	
              1122(d)(1)(ii)

            	
              If
                any material servicing activities are outsourced to third parties,
                policies and procedures are instituted to monitor the third party’s
                performance and compliance with such servicing activities.


            	 	
              X

            	
              X

            
	
              1122(d)(1)(iii)

            	
              Any
                requirements in the transaction agreements to maintain a back-up
                servicer
                for the pool assets are maintained. 

            	 	 	
              X

            
	
              1122(d)(1)(iv)

            	
              A
                fidelity bond and errors and omissions policy is in effect on the
                party
                participating in the servicing function throughout the reporting
                period in
                the amount of coverage required by and otherwise in accordance with
                the
                terms of the transaction agreements. 

            	 	 	
              X

            
	 	
              Cash Collection and Administration

            	 	 	 
	
              1122(d)(2)(i)

            	
              Payments
                on pool assets are deposited into the appropriate custodial bank
                accounts
                and related bank clearing accounts no more than two business days
                following receipt, or such other number of days specified in the
                transaction agreements. 

            	 	
              X

            	
              X

            
	
              1122(d)(2)(ii)

            	
              Disbursements
                made via wire transfer on behalf of an obligor or to an investor
                are made
                only by authorized personnel. 

            	 	
              X

            	
              X

            


    

     

    
      
        
        

      

      
        T-1

        
          

        

      

      
        
        

      

    

     

    
      	
              Regulation
                AB

              Reference

            	
              Servicing
                Criteria

            	
              Credit
                Risk Manager

            	
              Trustee

            	
              Master
                Servicer

            
	
              1122(d)(2)(iii)

            	
              Advances
                of funds or guarantees regarding collections, cash flows or distributions,
                and any interest or other fees charged for such advances, are made,
                reviewed and approved as specified in the transaction agreements.
                

            	 	 	
              X

            
	
              1122(d)(2)(iv)

            	
              The
                related accounts for the transaction, such as cash reserve accounts
                or
                accounts established as a form of over collateralization, are separately
                maintained (e.g., with respect to commingling of cash) as set forth
                in the
                transaction agreements. 

            	 	
              X

            	
              X

            
	
              1122(d)(2)(v)

            	
              Each
                custodial account is maintained at a federally insured depository
                institution as set forth in the transaction agreements. For purposes
                of
                this criterion, “federally insured depository institution” with respect to
                a foreign financial institution means a foreign financial institution
                that
                meets the requirements of Rule 13k-1(b)(1) of the Securities Exchange
                Act.
                

            	 	
              X

            	
              X

            
	
              1122(d)(2)(vi)

            	
              Unissued
                checks are safeguarded so as to prevent unauthorized access.
                

            	 	
              X

            	
              X

            
	
              1122(d)(2)(vii)
                

            	
              Reconciliations
                are prepared on a monthly basis for all asset-backed securities related
                bank accounts, including custodial accounts and related bank clearing
                accounts. These reconciliations are (A) mathematically accurate;
                (B)
                prepared within 30 calendar days after the bank statement cutoff
                date, or
                such other number of days specified in the transaction agreements;
                (C)
                reviewed and approved by someone other than the person who prepared
                the
                reconciliation; and (D) contain explanations for reconciling items.
                These
                reconciling items are resolved within 90 calendar days of their original
                identification, or such other number of days specified in the transaction
                agreements. 

            	 	
              X

            	
              X

            
	 	
              Investor
                Remittances and Reporting

            	 	 	 
	
              1122(d)(3)(i)

            	
              Reports
                to investors, including those to be filed with the Commission, are
                maintained in accordance with the transaction agreements and applicable
                Commission requirements. Specifically, such reports (A) are prepared
                in
                accordance with timeframes and other terms set forth in the transaction
                agreements; (B) provide information calculated in accordance with
                the
                terms specified in the transaction agreements; (C) are filed with
                the
                Commission as required by its rules and regulations; and (D) agree
                with
                investors’ or the trustee’s records as to the total unpaid principal
                balance and number of pool assets serviced by the Servicer.
                

            	
              X

            	
              X

            	
              X

            


    

     

    
      
        
        

      

      
        T-2

        
          

        

      

      
        
        

      

    

     

    
      	
              Regulation
                AB

              Reference

            	
              Servicing
                Criteria

            	
              Credit
                Risk Manager

            	 

              Trustee

            	
              Master
                Servicer

            
	
              1122(d)(3)(ii)

            	
              Amounts
                due to investors are allocated and remitted in accordance with timeframes,
                distribution priority and other terms set forth in the transaction
                agreements. 

            	 	
              X

            	
              X

            
	
              1122(d)(3)(iii)

            	
              Disbursements
                made to an investor are posted within two business days to the Servicer’s
                investor records, or such other number of days specified in the
                transaction agreements. 

            	 	
              X

            	
              X

            
	
              1122(d)(3)(iv)

            	
              Amounts
                remitted to investors per the investor reports agree with cancelled
                checks, or other form of payment, or custodial bank statements.
                

            	 	
              X

            	
              X

            
	 	
              Pool
                Asset Administration

            	 	 	 
	
              1122(d)(4)(i)
                

            	
              Collateral
                or security on pool assets is maintained as required by the transaction
                agreements or related pool asset documents. 

            	 	 	 
	
              1122(d)(4)(ii)

            	
              Pool
                assets and related documents are safeguarded as required by the
                transaction agreements 

            	 	 	 
	
              1122(d)(4)(iii)

            	
              Any
                additions, removals or substitutions to the asset pool are made,
                reviewed
                and approved in accordance with any conditions or requirements in
                the
                transaction agreements. 

            	 	
              X

            	 
	
              1122(d)(4)(iv)

            	
              Payments
                on pool assets, including any payoffs, made in accordance with the
                related
                pool asset documents are posted to the Servicer’s obligor records
                maintained no more than two business days after receipt, or such
                other
                number of days specified in the transaction agreements, and allocated
                to
                principal, interest or other items (e.g., escrow) in accordance with
                the
                related pool asset documents. 

            	 	 	 


    

     

    
      
        
        

      

      
        T-3

        
          

        

      

      
        
        

      

    

     

    
      	
              Regulation
                AB

              Reference

            	
              Servicing
                Criteria

            	
              Credit
                Risk Manager

            	
              Trustee

            	
              Master
                Servicer

            
	
              1122(d)(4)(v)

            	
              The
                Servicer’s records regarding the pool assets agree with the Servicer’s
                records with respect to an obligor’s unpaid principal balance.
                

            	 	 	 
	
              1122(d)(4)(vi)

            	
              Changes
                with respect to the terms or status of an obligor's pool assets (e.g.,
                loan modifications or re-agings) are made, reviewed and approved
                by
                authorized personnel in accordance with the transaction agreements
                and
                related pool asset documents. 

            	 	 	
              X

            
	
              1122(d)(4)(vii)

            	
              Loss
                mitigation or recovery actions (e.g., forbearance plans, modifications
                and
                deeds in lieu of foreclosure, foreclosures and repossessions, as
                applicable) are initiated, conducted and concluded in accordance
                with the
                timeframes or other requirements established by the transaction
                agreements. 

            	 	 	
              X

            
	
              1122(d)(4)(viii)

            	
              Records
                documenting collection efforts are maintained during the period a
                pool
                asset is delinquent in accordance with the transaction agreements.
                Such
                records are maintained on at least a monthly basis, or such other
                period
                specified in the transaction agreements, and describe the entity’s
                activities in monitoring delinquent pool assets including, for example,
                phone calls, letters and payment rescheduling plans in cases where
                delinquency is deemed temporary (e.g., illness or unemployment).
                

            	 	 	 
	
              1122(d)(4)(ix)

            	
              Adjustments
                to interest rates or rates of return for pool assets with variable
                rates
                are computed based on the related pool asset documents. 

            	 	 	 
	
              1122(d)(4)(x)

            	
              Regarding
                any funds held in trust for an obligor (such as escrow accounts):
                (A) such
                funds are analyzed, in accordance with the obligor’s pool asset documents,
                on at least an annual basis, or such other period specified in the
                transaction agreements; (B) interest on such funds is paid, or credited,
                to obligors in accordance with applicable pool asset documents and
                state
                laws; and (C) such funds are returned to the obligor within 30 calendar
                days of full repayment of the related pool assets, or such other
                number of
                days specified in the transaction agreements. 

            	 	 	 


    

     

    
      
        
        

      

      
        T-4

        
          

        

      

      
        
        

      

    

     

    
      	
              Regulation
                AB

              Reference

            	
              Servicing
                Criteria

            	
              Credit
                Risk Manager

            	
              Trustee

            	
              Master
                Servicer

            
	
              1122(d)(4)(xi)

            	
              Payments
                made on behalf of an obligor (such as tax or insurance payments)
                are made
                on or before the related penalty or expiration dates, as indicated
                on the
                appropriate bills or notices for such payments, provided that such
                support
                has been received by the servicer at least 30 calendar days prior
                to these
                dates, or such other number of days specified in the transaction
                agreements. 

            	 	 	
               

            
	
              1122(d)(4)(xii)

            	
              Any
                late payment penalties in connection with any payment to be made
                on behalf
                of an obligor are paid from the Servicer’s funds and not charged to the
                obligor, unless the late payment was due to the obligor’s error or
                omission. 

            	 	 	
               

            
	
              1122(d)(4)(xiii)

            	
              Disbursements
                made on behalf of an obligor are posted within two business days
                to the
                obligor’s records maintained by the servicer, or such other number of days
                specified in the transaction agreements. 

            	 	 	
               

            
	
              1122(d)(4)(xiv)
                

            	
              Delinquencies,
                charge-offs and uncollectible accounts are recognized and recorded
                in
                accordance with the transaction agreements. 

            	 	 	
              X

            
	
              1122(d)(4)(xv)

            	
              Any
                external enhancement or other support, identified in Item 1114(a)(1)
                through (3) or Item 1115 of Regulation AB, is maintained as set forth
                in
                the transaction agreements. 

            	 	
              X*

            	 


    

     

    *
      Only
      with respect to the Certificate Insurance Policy, if applicable.

    


    
      
        
        

      

      
        T-5

        
          

        

      

      
        
        

      

    

     

    EXHIBIT
      U

     

    FORM
      OF
      CERTIFICATION TO BE PROVIDED 

     

    BY
      THE
      CREDIT RISK MANAGER

     

    


    Re:
      Structured Asset Securities Corporation Mortgage Pass-Through Certificates,
      Series 2006-S4 issued pursuant to the Trust Agreement dated as of
      December 1, 2006, among Structured Asset Securities Corporation, as the
      Depositor (the “Depositor”), Aurora Loan Services LLC, as Master Servicer,
      Clayton Fixed Income Services Inc. as Credit Risk Manager, and Citibank, N.A.,
      as Trustee (the “Trustee”).

    


    CLAYTON
      FIXED INCOME SERVICES INC. (the “Credit Risk Manager”) certifies to the
      Depositor, the Trustee, and [10-K Signatory Entity], its officers, directors
      and
      affiliates, and with the knowledge and intent that they will rely upon this
      certification, that: 

    


    
      	 	
              1.

            	
              Based
                on the knowledge of the Credit Risk Manager taken as a whole, the
                information in the reports provided during the calendar year immediately
                preceding the date of this certificate (the “Relevant Year”) by the Credit
                Risk Manager pursuant to the Master Consulting Agreement dated as
                of
                January 28, 2004 (the “Master Consulting Agreement”), by and between the
                Credit Risk Manager and Lehman Brothers Holdings, Inc. and pursuant
                to
                Transaction Addendum SASCO 2006-S4 (the “Transaction Addendum SASCO
                2006-S4”), does not contain any untrue statement of a material fact or
                omit to state a material fact necessary to make the statements made,
                in
                light of the circumstances under which such statements were made,
                not
                misleading as of the date that each of such reports was provided;
                and
                

            


    

     

    
      	 	
              2.

            	
              The
                Credit Risk Manager has fulfilled its obligations under the Master
                Consulting Agreement and the Transaction Addendum SASCO 2006-S4 throughout
                the Relevant Year. 

            


    

     

    CLAYTON
      FIXED INCOME SERVICES INC.

     

    By:
      ________________________     

    


    Name:
      ______________________ 

    


    Title:
      _______________________

    


    
      
        
        

      

      
        U-1

        
          

        

      

      
        
        

      

    

    


    EXHIBIT
      V

     

    


    TRANSACTION
      PARTIES

    


    

      
        	
                Sponsor
                  and Seller:

              	
                Lehman
                  Brothers Holdings Inc.

              
	 	 
	
                Depositor:

              	
                Structured
                  Asset Securities Corporation

              
	 	 
	
                Trustee:

              	
                Citibank,
                  N.A.

              
	 	 
	
                Master
                  Servicer:

              	
                Aurora
                  Loan Services LLC

              
	 	 
	
                Credit
                  Risk Manager:

              	
                Clayton
                  Fixed Income Services Inc.

              
	 	 
	
                Swap
                  Counterparty:

              	
                Wachovia
                  Bank, National Association

              
	 	 
	
                Servicer(s):

              	
                Aurora
                  Loan Services LLC

              
	 	 
	
                Originator(s):

              	
                Lehman
                  Brothers Bank FSB

              
	 	 
	
                Custodian(s):

              	
                LaSalle
                  Bank National Association and U.S. Bank National
                  Association

              


      



    
      
        
        

      

      
        V-1

        
          

        

      

      
        
        

      

    

     

    SCHEDULE
      A

     

    MORTGAGE
      LOAN SCHEDULE

    


    [To
      be
      retained in a separate closing binder entitled “SASCO 2006-S4 Mortgage Loan
      Schedules” at the Seattle, Washington offices of Heller Ehrman LLP]

     

    


    
      
        
        

      

      
        Sch.
          A-1

        
          

        

      

      
        
        

      

    

     

    SCHEDULE
      B

     

    FIRST
      PAYMENT DEFAULT MORTGAGE LOANS

    


    [To
      be
maintained
      in a separate closing binder entitled “SASCO 2006-S4 First Payment Default
      Mortgage Loans” at the Seattle, Washington offices of Heller Ehrman
      LLP]

    


    
      
        
        

      

      
        Sch.
          B-1