Document:

<PAGE>
                                                                   EXHIBIT 10.59

                      SUMMARY OF APPROVED 2005 BASE SALARY

The Compensation Committee of Genesee & Wyoming Inc. approved increases to
the annual base salary of the following executive officers, effective as of
January 1, 2005:

<TABLE>
<CAPTION>
NAME AND POSITION                                                                        ANNUAL BASE SALARY
-----------------                                                                        ------------------
<S>                                                                                      <C>
Mortimer B. Fuller III, Chairman of the Board and Chief Executive Officer                     $622,000
John C. Hellmann, Chief Financial Officer                                                     $346,000
Charles N. Marshall, President and Chief Operating Officer                                    $346,000
Adam B. Frankel, Senior Vice President, General Counsel & Secretary                           $250,000
James M. Andres, Senior Vice President, Chief Accounting Officer and Global Controller        $170,000
</TABLE><PAGE>

                                                                     EXHIBIT 4.1

             STRUCTURED ASSET SECURITIES CORPORATION, as Depositor,

                  AURORA LOAN SERVICES LLC, as Master Servicer,

                     WELLS FARGO BANK, NATIONAL ASSOCIATION,

                           as Securities Administrator

                                       and

                 HSBC BANK USA, NATIONAL ASSOCIATION, as Trustee

                                 TRUST AGREEMENT

                          Dated as of February 1, 2005

                 STRUCTURED ADJUSTABLE RATE MORTGAGE LOAN TRUST
                       MORTGAGE PASS-THROUGH CERTIFICATES
                                  SERIES 2005-4

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                               PAGE
                                                                                                               ----
<S>                                                                                                            <C>
ARTICLE I DEFINITIONS........................................................................................   14

   Section 1.01.  Definitions................................................................................   14
   Section 1.02.  Calculations Respecting Mortgage Loans.....................................................   52

ARTICLE II DECLARATION OF TRUST; ISSUANCE OF CERTIFICATES....................................................   52

   Section 2.01.  Creation and Declaration of Trust Fund; Conveyance of Mortgage Loans.......................   52
   Section 2.02.  Acceptance of Trust Fund by Trustee: Review of Documentation for Trust Fund................   56
   Section 2.03.  Representations and Warranties of the Depositor............................................   58
   Section 2.04.  Discovery of Breach........................................................................   60
   Section 2.05.  Repurchase, Purchase or Substitution of Mortgage Loans.....................................   60
   Section 2.06.  Grant Clause...............................................................................   61

ARTICLE III THE CERTIFICATES.................................................................................   62

   Section 3.01.  The Certificates...........................................................................   62
   Section 3.02.  Registration...............................................................................   63
   Section 3.03.  Transfer and Exchange of Certificates......................................................   64
   Section 3.04.  Cancellation of Certificates...............................................................   70
   Section 3.05.  Replacement of Certificates................................................................   70
   Section 3.06.  Persons Deemed Owners......................................................................   70
   Section 3.07.  Temporary Certificates.....................................................................   70
   Section 3.08.  Appointment of Paying Agent................................................................   71
   Section 3.09.  Book-Entry Certificates....................................................................   71

ARTICLE IV ADMINISTRATION OF THE TRUST FUND..................................................................   72

   Section 4.01.  Collection Account.........................................................................   72
   Section 4.02.  Application of Funds in the Collection Account.............................................   74
   Section 4.03.  Reports to Certificateholders..............................................................   77
   Section 4.04.  Certificate Account........................................................................   80
   Section 4.05.  Determination of LIBOR.....................................................................   81

ARTICLE V DISTRIBUTIONS TO HOLDERS OF CERTIFICATES...........................................................   82

   Section 5.01.  Distributions Generally....................................................................   82
   Section 5.02.  Distributions from the Certificate Account.................................................   83
   Section 5.03.  Allocation of Realized Losses..............................................................   93
   Section 5.04.  Advances by the Master Servicer and the Securities Administrator...........................   95
   Section 5.05.  Compensating Interest Payments.............................................................   96

ARTICLE VI CONCERNING THE TRUSTEE AND THE SECURITIES ADMINISTRATOR;  EVENTS OF DEFAULT.......................   96

   Section 6.01.  Duties of Trustee and Securities Administrator.............................................   96
</TABLE>

                                        i
<PAGE>

<TABLE>
<S>                                                                                                             <C>
   Section 6.02.  Certain Matters Affecting the Trustee and the Securities Administrator.....................   99
   Section 6.03.  Trustee and Securities Administrator Not Liable for Certificates...........................   100
   Section 6.04.  Trustee and Securities Administrator May Own Certificates..................................   101
   Section 6.05.  Eligibility Requirements for Trustee and Securities Administrator..........................   101
   Section 6.06.  Resignation and Removal of Trustee and Securities Administrator............................   101
   Section 6.07.  Successor Trustee and Successor Securities Administrator...................................   102
   Section 6.08.  Merger or Consolidation of Trustee or Securities Administrator.  ..........................   103
   Section 6.09.  Appointment of Co-Trustee, Separate Trustee or Custodian...................................   103
   Section 6.10.  Authenticating Agents......................................................................   105
   Section 6.11.  Indemnification of Trustee and Securities Administrator....................................   106
   Section 6.12.  Fees and Expenses of Securities Administrator, Trustee and Custodian.......................   107
   Section 6.13.  Collection of Monies.......................................................................   107
   Section 6.14.  Events of Default; Securities Administrator To Act;
                  Appointment of Successor...................................................................   107
   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.  Reporting Requirements of the Commission...................................................   115

ARTICLE VII PURCHASE AND TERMINATION OF THE TRUST FUND.......................................................   115

   Section 7.01.  Termination of Trust Fund Upon Repurchase or Liquidation of All Mortgage Loans.............   115
   Section 7.02.  Procedure Upon Termination of Trust Fund...................................................   116
   Section 7.03.  Additional Requirements under the REMIC Provisions.........................................   117

ARTICLE VIII RIGHTS OF CERTIFICATEHOLDERS....................................................................   118

   Section 8.01.  Limitation on Rights of Holders............................................................   118
   Section 8.02.  Access to List of Holders..................................................................   119
   Section 8.03.  Acts of Holders of Certificates............................................................   119

ARTICLE IX ADMINISTRATION AND SERVICING OF MORTGAGE LOANS BY THE MASTER SERVICER.............................   120

   Section 9.01.  Duties of the Master Servicer..............................................................   120
   Section 9.02.  Master Servicer Fidelity Bond and Master Servicer Errors and Omissions Insurance Policy....   121
   Section 9.03.  Master Servicer's Financial Statements and Related Information.............................   121
   Section 9.04.  Power to Act; Procedures...................................................................   121
   Section 9.05.  Servicing Agreements Between the Master Servicer and Servicers; Enforcement of Servicers'
                  Obligations................................................................................   124
   Section 9.06.  Collection of Taxes, Assessments and Similar Items.........................................   124
   Section 9.07.  Termination of Servicing Agreements; Successor Servicers...................................   125
</TABLE>

                                       ii
<PAGE>

<TABLE>
<S>                                                                                                             <C>
   Section 9.08.  Master Servicer Liable for Enforcement.....................................................   126
   Section 9.09.  No Contractual Relationship Between Servicers and Trustee or Depositor.....................   126
   Section 9.10.  Assumption of Servicing Agreement by Securities Administrator..............................   126
   Section 9.11.  "Due - on - Sale" Clauses; Assumption Agreements...........................................   127
   Section 9.12.  Release of Mortgage Files..................................................................   127
   Section 9.13.  Documents, Records and Funds in Possession of Master Servicer
                  To Be Held for Trustee.....................................................................   128
   Section 9.14.  Representations and Warranties of the Master Servicer......................................   130
   Section 9.15.  Closing Certificate and Opinion............................................................   132
   Section 9.16.  Standard Hazard and Flood Insurance Policies...............................................   132
   Section 9.17.  Presentment of Claims and Collection of Proceeds...........................................   133
   Section 9.18.  Maintenance of the Primary Mortgage Insurance Policies.....................................   133
   Section 9.19.  Trustee To Retain Possession of Certain Insurance Policies and Documents...................   133
   Section 9.20.  Realization Upon Defaulted Mortgage Loans..................................................   134
   Section 9.21.  Compensation to the Master Servicer........................................................   134
   Section 9.22.  REO Property...............................................................................   135
   Section 9.23.  [Reserved].................................................................................   136
   Section 9.24.  Reports to the Trustee and the Securities Administrator....................................   136
   Section 9.25.  Annual Officer's Certificate as to Compliance..............................................   136
   Section 9.26.  Annual Independent Accountants' Servicing Report...........................................   137
   Section 9.27.  Merger or Consolidation....................................................................   138
   Section 9.28.  Resignation of Master Servicer.............................................................   138
   Section 9.29.  Assignment or Delegation of Duties by the Master Servicer..................................   138
   Section 9.30.  Limitation on Liability of the Master Servicer and Others..................................   139
   Section 9.31.  Indemnification; Third-Party Claims........................................................   140

ARTICLE X REMIC ADMINISTRATION...............................................................................   140

   Section 10.01. REMIC and Grantor Trust Administration.....................................................   140
   Section 10.02. Prohibited Transactions and Activities.....................................................   145
   Section 10.03. Indemnification with Respect to Certain Taxes and Loss of REMIC Status.....................   146
   Section 10.04. REO Property...............................................................................   146

ARTICLE XI MISCELLANEOUS PROVISIONS..........................................................................   147

   Section 11.01. Binding Nature of Agreement; Assignment....................................................   147
   Section 11.02. Entire Agreement...........................................................................   147
   Section 11.03. Amendment..................................................................................   147
   Section 11.04. Voting Rights..............................................................................   149
   Section 11.05. Provision of Information...................................................................   149
   Section 11.06. Governing Law..............................................................................   149
   Section 11.07. Notices....................................................................................   149
   Section 11.08. Severability of Provisions.................................................................   150
   Section 11.09. Indulgences; No Waivers....................................................................   150
   Section 11.10. Headings Not To Affect Interpretation......................................................   150
   Section 11.11. Benefits of Agreement......................................................................   150
   Section 11.12. Special Notices to the Rating Agencies.....................................................   151
   Section 11.13. Counterparts...............................................................................   151
</TABLE>

                                       iii
<PAGE>

<TABLE>
<S>                                                                                                          <C>
Section 11.14. Transfer of Servicing......................................................................   151
</TABLE>

                                       iv
<PAGE>

                                   ATTACHMENTS

<TABLE>
<CAPTION>
<S>               <C>
Exhibit A         Forms of Certificates
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-l       Form of Residual Certificate Transfer Affidavit (Transferee)
Exhibit D-2       Form of Residual Certificate Transfer Affidavit (Transferor)
Exhibit E         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         Monthly Remittance Advice
Exhibit J         Monthly Electronic Data Transmission
Exhibit K         Custodial Agreements
Exhibit L-1       Form of Transfer Certificate for Transfer from Restricted Global Security to Regulation S
                  Global Security
Exhibit L-2       Form of Transfer Certificate for Transfer from Regulation S Global Security to Restricted
                  Global Security
Exhibit M         Form of Certification to be Provided to the Depositor and the Master Servicer by the Trustee

Schedule A        Mortgage Loan Schedule
Schedule B        Pool 3 AX Mortgage Loan Schedule
Schedule C        Pool 3 PAX Mortgage Loan Schedule
</TABLE>

<PAGE>

      This TRUST AGREEMENT, dated as of February 1, 2005 (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"), WELLS FARGO BANK, NATIONAL ASSOCIATION, a national banking
corporation, as securities administrator (the "Securities Administrator") and
HSBC BANK USA, NATIONAL ASSOCIATION, a national banking association, as trustee
(the "Trustee").

                              PRELIMINARY STATEMENT

      The Depositor has acquired the Mortgage Loans from Lehman Brothers
Holdings (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 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
Depositor, the Master Servicer, the Securities Administrator 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. The Depositor, the Securities Administrator and the Master
Servicer 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, the Trustee shall elect that the Trust Fund (other
than the rights to Prepayment Penalty Amounts) be treated for federal income tax
purposes as comprising six real estate mortgage investment conduits (each a
"REMIC" or, in the alternative, REMIC I-1, REMIC I-2, REMIC I-3, REMIC I-4,
REMIC II-1 and REMIC II-2). As is described in Section 10.01 hereof, the Trust
Fund will also be treated for federal income tax purposes as including five
grantor trusts.

      Each Group I Certificate, other than the Class R Certificates, represents
ownership of a regular interest in REMIC I-4 for purposes of the REMIC
Provisions. Each Group II Certificate represents ownership of one or more
regular interests in REMIC II-2 for purposes of the REMIC Provisions. The Class
R Certificate represents ownership of the sole class of residual interest in
each of REMIC I-1, REMIC I-2, REMIC I-3, REMIC I-4, REMIC II-1 and REMIC II-2
for purposes of the REMIC Provisions.

      Each REMIC I-4 Regular Interest is hereby designated as a regular interest
in REMIC I-4. REMIC I-4 shall hold as assets the several classes of
uncertificated REMIC I-3 Regular Interests, the Class LTI2-3AXIO Interest and
the Class LTI2-3PAXIO Interest. Each REMIC I-3 Regular Interest is hereby
designated as a regular interest in REMIC I-3. REMIC I-3 shall hold as assets
the several classes of uncertificated REMIC I-2 Regular Interests, other than
the Class LTI2-3AXIO Interest and the Class LTI2-3PAXIO Interest. Each REMIC I-2
Regular Interest is hereby designated as a regular interest in REMIC I-2. REMIC
I-2 shall hold as assets the several classes of uncertificated REMIC I-1 Regular
Interests. Each REMIC I-1 Regular Interest is hereby designated as a regular
interest in REMIC I-1. REMIC I-1 shall hold as assets all property of the Trust
Fund relating to Mortgage Group I other than the REMIC I-1 Interests, the

<PAGE>

REMIC I-2 Interests, the REMIC I-3 Interests, the REMIC I-4 Regular Interests,
the REMIC I-4 Residual Interest and the rights to Prepayment Penalty Amounts.

      Each REMIC II-2 Regular Interest is hereby designated as a regular
interest in REMIC II-2. REMIC II-2 shall hold as assets the several classes of
uncertificated REMIC II-1 Regular Interests. Each REMIC II-1 Regular Interest is
hereby designated as a regular interest in REMIC II-1. REMIC II-1 shall hold as
assets all property of the Trust Fund relating to Mortgage Group II other than
the REMIC II-1 Interests, the REMIC II-2 Regular Interests, the REMIC II-2
Residual Interest and the rights to Prepayment Penalty Amounts.

REMIC I-1

      The following table specifies the class designation, interest rate,
principal amount and related Mortgage Pool for each class of REMIC I-1
Interests.

<TABLE>
<CAPTION>
REMIC I-1 Class                    Initial Class or Principal
  Designation       Interest Rate            Amount             Related Pool or Pools
---------------     -------------  --------------------------   ---------------------
<S>                 <C>            <C>                          <C>
Class LTI1-1             (1)          $  249,297,474.86               Pool 1
Class LTI1-2             (2)          $  180,910,330.56               Pool 2
Class LTI1-3AX           (3)          $  154,251,544.68               Pool 3
Class LTI1-3PAX          (4)          $   59,900,276.73               Pool 3
Class LTI1-4             (5)          $  105,979,073.16               Pool 4
Class LTI1-5             (6)          $   46,702,425.11               Pool 5
Class LTI1-R             (7)                         (7)               N/A
</TABLE>

---------------------

(1)   For any Distribution Date, the interest rate for the Class LTI1-1
      Interest shall be a per annum rate equal to the weighted average of the
      Net Mortgage Rates of the Pool 1 Mortgage Loans at the beginning of the
      related Due Period, weighted on the basis of their respective Scheduled
      Principal Balances.

(2)   For any Distribution Date, the interest rate for the Class LTI1-2
      Interest shall be a per annum rate equal to the weighted average of the
      Net Mortgage Rates of the Pool 2 Mortgage Loans at the beginning of the
      related Due Period, weighted on the basis of their respective Scheduled
      Principal Balances.

(3)   For any Distribution Date prior to the Distribution Date in December
      2009, the interest rate for the Class LTI1-3AX Interest shall be a per
      annum rate equal to the weighted average of the Net Mortgage Rates of the
      Pool 3 AX Mortgage Loans at the beginning of the related Due Period,
      weighted on the basis of their respective Scheduled Principal Balances.
      For each Distribution Date starting with the Distribution Date in December
      2009, the interest rate for the Class LTI1-3AX Interest shall be a per
      annum rate equal to the weighted average of the Net Mortgage Rates of the
      Pool 3 Mortgage Loans at the beginning of the related Due Period, weighted
      on the basis of their respective Scheduled Principal Balances.

                                        2
<PAGE>

(4)   For any Distribution Date prior to the Distribution Date in December
      2009, the interest rate for the Class LTI1-3PAX Interest shall be a per
      annum rate equal to the weighted average of the Net Mortgage Rates of the
      Pool 3 PAX Mortgage Loans at the beginning of the related Due Period,
      weighted on the basis of their respective Scheduled Principal Balances.
      For each Distribution Date starting with the Distribution Date in December
      2009, the interest rate for the Class LTI1-3PAX Interest shall be a per
      annum rate equal to the weighted average of the Net Mortgage Rates of the
      Pool 3 Mortgage Loans at the beginning of the related Due Period, weighted
      on the basis of their respective Scheduled Principal Balances.

(5)   For any Distribution Date, the interest rate for the Class LTI1-4
      Interest shall be a per annum rate equal to the weighted average of the
      Net Mortgage Rates of the Pool 4 Mortgage Loans at the beginning of the
      related Due Period, weighted on the basis of their respective Scheduled
      Principal Balances.

(6)   For any Distribution Date, the interest rate for the Class LTI1-5
      Interest shall be a per annum rate equal to the weighted average of the
      Net Mortgage Rates of the Pool 5 Mortgage Loans at the beginning of the
      related Due Period, weighted on the basis of their respective Scheduled
      Principal Balances.

(7)   The Class LTI1-R Interest shall represent the sole class of residual
      interest in REMIC I-1. The Class LTI1-R Interest will not have a principal
      amount or an interest rate. The Class LTI1-R Interest shall be represented
      by the Class R Certificate.

      All Realized Losses from the Pool 1 Mortgage Loans shall be allocated to
the Class LTI1-1 Interest and all payments of principal and interest received
with respect to the Pool 1 Mortgage Loans shall be paid on the Class LTI1-1
Interest in payment of accrued interest and principal until the principal
balance of such Class is reduced to zero and any losses allocated to such Class
have been reimbursed.

      All Realized Losses from the Pool 2 Mortgage Loans shall be allocated to
the Class LTI1-2 Interest and all payments of principal and interest received
with respect to the Pool 2 Mortgage Loans shall be paid on the Class LTI1-2
Interest in payment of accrued interest and principal until the principal
balance of such Class is reduced to zero and any losses allocated to such Class
have been reimbursed.

      All Realized Losses from the Pool 3 AX Mortgage Loans shall be allocated
to the Class LTI1-3AX Interest and all payments of principal and, for
Distribution Dates prior to the Distribution Date in December 2009, interest
received with respect to the Pool 3 AX Mortgage Loans shall be paid on the Class
LTI1-3AX Interest in payment of accrued interest and principal until the
principal balance of such Class is reduced to zero and any losses allocated to
such Class have been reimbursed.

      All Realized Losses from the Pool 3 PAX Mortgage Loans shall be allocated
to the Class LTI1-3PAX Interest and all payments of principal and, for
Distribution Dates prior to the Distribution Date in December 2009, interest
received with respect to the Pool 3 PAX Mortgage Loans shall be paid on the
Class LTI1-3PAX Interest in payment of accrued interest and

                                        3
<PAGE>

principal until the principal balance of such Class is reduced to zero and any
losses allocated to such Class have been reimbursed.

      For each Distribution Date starting with the Distribution Date in December
2009, interest received on the Pool 3 Mortgage Loans will be distributed in
respect of the Class LTI1-3AX Interest and the Class LTI1-3PAX Interest in
proportion to the relative outstanding unpaid interest amounts for those
Interests.

      All Realized Losses from the Pool 4 Mortgage Loans shall be allocated to
the Class LTI1-4 Interest and all payments of principal and interest received
with respect to the Pool 4 Mortgage Loans shall be paid on the Class LTI1-4
Interest in payment of accrued interest and principal until the principal
balance of such Class is reduced to zero and any losses allocated to such Class
have been reimbursed.

      All Realized Losses from the Pool 5 Mortgage Loans shall be allocated to
the Class LTI1-5 Interest and all payments of principal and interest received
with respect to the Pool 5 Mortgage Loans shall be paid on the Class LTI1-5
Interest in payment of accrued interest and principal until the principal
balance of such Class is reduced to zero and any losses allocated to such Class
have been reimbursed.

      If on any Distribution Date there is an increase in the Certificate
Principal Amount of any Class of Certificates as a result of the proviso in the
definition of Certificate Principal Amount, then there shall be a corresponding
increase in the principal amount of the REMIC I-1 Interests, with the increase
allocated among such REMIC I-1 Interests in a manner that reflects the Mortgage
Pool with respect to which the Subsequent Recovery was made (and, in the case of
Subsequent Recoveries with respect to Pool 3, whether the Subsequent Recovery
was in respect of a Pool 3 AX Mortgage Loan or a Pool 3 PAX Mortgage Loan).

REMIC I-2

      The following table specifies the class designation, interest rate,
principal amount and related Mortgage Pool for each class of REMIC I-2
Interests.

                                        4
<PAGE>

<TABLE>
<CAPTION>
    REMIC I-2                     Initial Class or Principal  Related Pool or
Class Designation  Interest Rate            Amount                  Pools
-----------------  -------------  --------------------------  ---------------
<S>                <C>            <C>                         <C>
Class LTI2-1           (1)             $ 249,297,474.86           Pool 1
Class LTI2-2           (2)             $ 180,910,330.56           Pool 2
Class LTI2-3AX         (3)             $ 154,251,544.68           Pool 3
Class LTI2-3AXIO       (4)                          (10)          Pool 3
Class LTI2-3PAX        (5)             $  59,900,276.73           Pool 3
Class LTI2-3PAXIO      (6)                          (11)          Pool 3
Class LTI2-4           (7)             $ 105,979,073.16           Pool 4
Class LTI2-5           (8)             $  46,702,425.11           Pool 5
Class LTI2-R           (9)                           (9)           N/A
</TABLE>

---------------------

(1)   For any Distribution Date, the interest rate for the Class LTI2-1
      Interest shall be the interest rate on the Class LTI1-1 Interest.

(2)   For any Distribution Date, the interest rate for the Class LTI2-2
      Interest shall be the interest rate on the Class LTI1-2 Interest.

(3)   For any Distribution Date prior to the Distribution Date in December
      2009, the interest rate for the Class LTI2-3AX Interest shall be the
      lesser of (i) 5.12% and (ii) the interest rate on the Class LTI1-3AX
      Interest. For each Distribution Date starting with the Distribution Date
      in December 2009, the interest rate for the Class LTI2-3AX Interest shall
      be the interest rate on the Class LTI1-3AX Interest.

(4)   For any Distribution Date prior to the Distribution Date in December
      2009, the interest rate for the Class LTI2-3AXIO Interest shall be equal
      to the excess, if any, of (i) the interest rate on the Class LTI1-3AX
      Interest over (ii) 5.12%. The Class LTI2-3AXIO Interest shall not be
      entitled to any distributions in respect of Distribution Dates after
      November 2009.

(5)   For any Distribution Date prior to the Distribution Date in December
      2009, the interest rate for the Class LTI2-3PAX Interest shall be the
      lesser of (i) 5.12% and (ii) the interest rate on the Class LTI1-3PAX
      Interest. For each Distribution Date starting with the Distribution Date
      in December 2009, the interest rate for the Class LTI2-3PAX Interest shall
      be the interest rate on the Class LTI1-3PAX Interest.

(6)   For any Distribution Date prior to the Distribution Date in December
      2009, the interest rate for the Class LTI2-3PAXIO Interest shall be equal
      to the excess, if any, of (i) the interest rate on the Class LTI1-3PAX
      Interest over (ii) 5.12%. The Class LTI2-3PAXIO Interest shall not be
      entitled to any distributions in respect of Distribution Dates after
      November 2009.

(7)   For any Distribution Date, the interest rate for the Class LTI2-4
      Interest shall be the interest rate on the Class LTI1-4 Interest.

(8)   For any Distribution Date, the interest rate for the Class LTI2-5
      Interest shall be the interest rate on the Class LTI1-5 Interest.

                                        5
<PAGE>

(9)   The Class LTI2-R Interest shall represent the sole class of residual
      interest in REMIC I-2. The Class LTI2-R Interest will not have a principal
      amount or an interest rate. The Class LTI2-R Interest shall be represented
      by the Class R Certificate.

(10)  For any Distribution Date prior to the Distribution Date in December
      of 2009, the Class LTI2-3AXIO Interest shall bear interest on a notional
      amount equal to the aggregate Scheduled Principal Balance of the Pool 3 AX
      Mortgage Loans. For any subsequent Distribution Date, the notional amount
      of the Class LTI2-3AXIO Interest shall be zero.

(11)  For any Distribution Date prior to the Distribution Date in December
      of 2009, the Class LTI2-3PAXIO Interest shall bear interest on a notional
      amount equal to the aggregate Scheduled Principal Balance of the Pool 3
      PAX Mortgage Loans. For any subsequent Distribution Date, the notional
      amount of the Class LTI2-3PAXIO Interest shall be zero.

      All losses and shortfalls allocated to the Class LTI1-1 Interest shall be
allocated to the Class LTI2-1 Interest. All distributions in respect of
principal, interest and reimbursements of previously allocated losses and
shortfalls on the Class LTI1-1 Interest shall be made to the Class LTI2-1
Interest.

      All losses and shortfalls allocated to the Class LTI1-2 Interest shall be
allocated to the Class LTI2-2 Interest. All distributions in respect of
principal, interest and reimbursements of previously allocated losses and
shortfalls on the Class LTI1-2 Interest shall be made to the Class LTI2-2
Interest.

      An amount of losses and shortfalls equal to the amount of losses and
shortfalls allocated to the Class 3-AX Certificates shall be allocated to the
Class LTI2-3AXIO Interest. An amount equal to the amount of all distributions
made, or deemed made under Section 5.02(j) hereof, to the Class 3-AX
Certificates shall be distributed to the Class LTI2-3AXIO Interest.

      All losses and shortfalls on the Pool 3 AX Mortgage Loans not allocated to
the Class 3-AX Certificates will be allocated to the Class LTI2-3AX Interest.
All distributions in respect of principal, interest and reimbursements of
previously allocated losses and shortfalls on the Class LTI1-3AX Interest in
excess of such amounts distributed or treated as distributed to the Class
LTI2-3AXIO Interest shall be treated as made in respect of the Class LTI2-3AX
Interest.

      An amount of losses and shortfalls equal to the amount of losses and
shortfalls allocated to the Class 3-PAX Certificates shall be allocated to the
Class LTI2-3PAXIO Interest. An amount equal to the amount of all distributions
made, or deemed made under Section 5.02(j) hereof, to the Class 3-PAX
Certificates shall be distributed to the Class LTI2-3PAXIO Interest.

      All losses and shortfalls on the Pool 3 PAX Mortgage Loans not allocated
to the Class 3-PAX Certificates will be allocated to the Class LTI2-3PAX
Interest. All distributions in respect of principal, interest and reimbursements
of previously allocated losses and shortfalls on the Class LTI1-3PAX Interest in
excess of such amounts distributed or treated as distributed to the Class
LTI2-3PAXIO Interest shall be treated as made in respect of the Class LTI2-3PAX
Interest.

                                        6
<PAGE>

      All losses and shortfalls allocated to the Class LTI1-4 Interest shall be
allocated to the Class LTI2-4 Interest. All distributions in respect of
principal, interest and reimbursements of previously allocated losses and
shortfalls on the Class LTI1-4 Interest shall be made to the Class LTI2-4
Interest.

      All losses and shortfalls allocated to the Class LTI1-5 Interest shall be
allocated to the Class LTI2-5 Interest. All distributions in respect of
principal, interest and reimbursements of previously allocated losses and
shortfalls on the Class LTI1-5 Interest shall be made to the Class LTI2-5
Interest.

      If on any Distribution Date there is an increase in the Certificate
Principal Amount of any Class of Certificates as a result of the proviso in the
definition of Certificate Principal Amount, then there shall be a corresponding
increase in the principal amount of the REMIC I-2 Interests (other than the
Class LTI2-3AXIO Interest and the Class LTI2-3PAXIO Interest), with the increase
allocated among such REMIC I-2 Interests in a manner that reflects the Mortgage
Pool with respect to which the Subsequent Recovery was made (and, in the case of
Subsequent Recoveries with respect to Pool 3, whether the Subsequent Recovery
was in respect of a Pool 3 AX Mortgage Loan or a Pool 3 PAX Mortgage Loan).

REMIC I-3

      The following table specifies the class designation, interest rate,
principal amount and related Mortgage Pool for each class of REMIC I-3
Interests.

<TABLE>
<CAPTION>
REMIC I-3 Class                 Initial Class or Principal
  Designation    Interest Rate            Amount             Related Pool or Pools
---------------  -------------  --------------------------   ---------------------
<S>              <C>            <C>                          <C>
Class LTI3-1A         (1)            $    168,283.7486             Pool 1
Class LTI3-1B         (2)            $  2,492,974.7486             Pool 1
Class LTI3-2A         (1)            $    122,123.3056             Pool 2
Class LTI3-2B         (3)            $  1,809,103.3056             Pool 2
Class LTI3-3A         (1)            $    144,558.2141             Pool 3
Class LTI3-3B         (4)            $  2,141,518.2141             Pool 3
Class LTI3-4A         (1)            $     71,540.7316             Pool 4
Class LTI3-4B         (5)            $  1,059,790.7316             Pool 4
Class LTI3-5A         (1)            $     31,524.2511             Pool 5
Class LTI3-5B         (6)            $    467,024.2511             Pool 5
Class LTI3-Z          (1)            $788,532,683.5980             N/A
Class LTI3-R          (7)                           (7)            N/A
</TABLE>

-----------------------

(1)   For any Distribution Date, the interest rate for the Class LTI3-1A,
      Class LTI3-2A, Class LTI3-3A, Class LTI3-4A, Class LT3-I5A and Class
      LTI3-Z Interest shall be the weighted average of the interest rates on the
      Class LTI2-1, Class LTI2-2, Class LTI2-3AX, Class LTI2-3PAX, Class LTI2-4
      and Class LTI2-5 Interests.

(2)   For any Distribution Date, the interest rate for the Class LTI3-1B
      Interest shall be the interest rate on the Class LTI2-1 Interest for such
      Distribution Date.

                                        7
<PAGE>

(3)   For any Distribution Date, the interest rate for the Class LTI3-2B
      Interest shall be the interest rate on the Class LTI2-2 Interest for such
      Distribution Date.

(4)   For any Distribution Date, the interest rate for the Class LTI3-3B
      Interest shall be the weighted average of the interest rates on the Class
      LTI2-3AX and LTI2-3PAX Interests for such Distribution Date.

(5)   For any Distribution Date, the interest rate for the Class LTI3-4B
      Interest shall be the interest rate on the Class LTI2-4 Interest for such
      Distribution Date.

(6)   For any Distribution Date, the interest rate for the Class LTI3-5B
      Interest shall be the interest rate on the Class LTI2-5 Interest for such
      Distribution Date.

(7)   The Class LTI3-R Interest shall represent the sole class of residual
      interest in REMIC I-3. The Class LTI3-R Interest will not have a principal
      amount or an interest rate. The Class LTI3-R Interest shall be represented
      by the Class R Certificate.

      Distributions shall be deemed to be made to the REMIC I-3 Regular
Interests first, so as to keep the principal balance of each REMIC I-3 Regular
Interest ending with the designation "B" equal to 1% of the aggregate Scheduled
Principal Balance of the Mortgage Loans in the related Mortgage Pool; second, to
each REMIC I-3 Regular Interest ending with the designation "A" so that the
principal balance of each such REMIC I-3 Regular Interest is equal to 1% of the
excess of (x) the aggregate Scheduled Principal Balance of the Mortgage Loans in
the related Mortgage Pool over (y) the aggregate Class Principal Amounts of the
Certificate Group related to such Mortgage Pool (except that if 1% of any such
excess is greater than the principal amount of the corresponding REMIC I-3
Regular Interest ending with the designation "A", the least amount of principal
shall be distributed to such REMIC I-3 Regular Interests such that the REMIC I-3
Subordinated Balance Ratio is maintained); and finally, any remaining principal
to the Class LTI3-Z Interest. Realized Losses shall be applied after all
distributions have been made on each Distribution Date first, so as to keep the
principal balance of each REMIC I-3 Regular Interest ending with the designation
"B" equal to 1% of the aggregate Scheduled Principal Balance of the Mortgage
Loans in the related Mortgage Pool; second, to each REMIC I-3 Regular Interest
ending with the designation "A" so that the principal balance of each such REMIC
I-3 Regular Interest is equal to 1% of the excess of (x) the aggregate Scheduled
Principal Balance of the Mortgage Loans in the related Mortgage Pool over (y)
the aggregate Class Principal Amounts of the Certificate Group related to such
Mortgage Pool (except that if 1% of any such excess is greater than the
principal amount of the corresponding REMIC I-3 Regular Interest ending with the
designation "A", the least amount of Realized Losses shall be allocated to such
REMIC I-3 Regular Interests such that the REMIC I-3 Subordinated Balance Ratio
is maintained); and third, the remaining Realized Losses shall be allocated to
the Class LTI3-Z Interest. All computations with respect to any REMIC I-3
Interest shall be taken out to eight decimal places.

      If on any Distribution Date there is an increase in the Certificate
Principal Amount of any Class of Certificates as a result of the proviso in the
definition of Certificate Principal Amount, then, prior to distributions of
principal and allocations of losses on such Distribution Date with respect to
REMIC I-3, there shall be a corresponding increase in the principal amount of
the REMIC I-3 Regular Interests, with such increase allocated among the REMIC
I-3 Regular Interests as follows: (i) first, to each REMIC I-3 Regular Interest
ending with the designation

                                        8
<PAGE>

"B" so as to keep the principal balance of such REMIC I-3 Regular Interest equal
to 1% of the aggregate Scheduled Principal Balance of the Mortgage Loans in the
related Mortgage Pool, (ii) second, to each REMIC I-3 Regular Interest ending
with the designation "A", so that the principal balance of each such REMIC I-3
Regular Interest is as close as possible to (but does not exceed) 1% of the
excess of (x) the aggregate Scheduled Principal balance of the Mortgage Loans in
the related Mortgage Pool over (y) the aggregate Class Principal Amounts of the
Senior Certificates of the Certificate Group related to such Mortgage Pool;
provided, however, that (a) the REMIC I-3 Subordinated Balance Ratio is
maintained and (b) amounts allocated to any REMIC I-3 Regular Interest pursuant
to this clause (ii) shall not exceed the amount of any previous realized losses
allocated to such REMIC I-3 Regular Interest not previously offset by
distributions or increases in the principal amount of such REMIC I-3 Regular
Interest and (iii) finally, all remaining increases are allocated to the Class
LTI3-Z Interest.

REMIC II-1

      The following table specifies the class designation, interest rate, and
initial principal amount for each class of REMIC II-1 Interests.

<TABLE>
<CAPTION>
  Designation    Interest Rate  Initial Principal Amount  Corresponding Certificates or Components
  -----------    -------------  ------------------------  ----------------------------------------
<S>              <C>            <C>                       <C>
LTII1-6A              (1)           $122,583,000.00          6-A1, 6-A2, 6-A3, 6-AX1, 6-AX2
LTII1-B1-II           (2)           $  2,980,000.00          B1-II, B1X-II Component
LTII1-B2-II           (2)           $    860,000.00          B2-II, B2X-II Component
LTII1-B3-II           (2)           $  2,052,000.00          B3-II, B3X-II Component
LTII1-B4-II           (2)           $  1,059,000.00          B4-II, B4X-II Component
LTII1-B5-II           (1)           $    794,000.00          B5-II
LTII1-B6-II           (1)           $    927,000.00          B6-II
LTII1-B7-II           (1)           $    662,000.00          B7-II
LTII1-B8-II           (1)           $    534,371.52          B8-II
LTII1-R               (3)                        (3)          N/A
</TABLE>

---------------------

(1)   For any Distribution Date, the interest rate for these interests
      shall be a per annum rate equal to the Net WAC for Pool 6 for such
      Distribution Date.

(2)   For any Distribution Date, the interest rate for these interests
      shall be a per annum rate equal to the Net WAC for Pool 6 for such
      Distribution Date multiplied by 30 and divided by the actual number of
      days in the related Accrual Period.

(3)   The Class LTII1-R Interest shall represent the sole class of
      residual interest in REMIC II-1. The Class LTII1-R Interest will not have
      a principal amount or an interest rate. The Class LTII1-R Interest shall
      be represented by the Class R Certificate.

Principal and interest shall be payable to, and shortfalls, losses, prepayments
and increases in principal amounts pursuant to the proviso in the definition of
Certificate Principal Amount are allocable to, the Class LTII1-6A Interest,
Class LTII1-B1-II Interest, Class LTII1-B2-II Interest, Class LTII1-B3-II
Interest, Class LTII1-B4-II Interest, Class LTII1-B5-II Interest, Class
LTII1-B6-II Interest, Class LTII1-B7-II Interest and Class LTII1-B8-II Interest
in the same amounts as such items (including distributions deemed made under
Section 5.02(a)(v)(O)) are allocated among the Corresponding Certificates or
Components (disregarding payments in respect of

                                        9
<PAGE>
Subordinate Floating Rate Certificate Shortfalls and Unpaid Subordinate
Floating Rate Certificate Shortfalls). Notwithstanding the preceding sentence,
(i) the first $0.52 of losses with respect to principal on the Mortgage Loans in
Pool 6 shall be allocated to the Class LTII1-B8-II Interest and (ii) immediately
preceding any payment to the Class R Certificate pursuant to Section 5.02(g)
attributable to principal received with respect to any Mortgage Loan, a payment
shall be treated as made to the Class LTII1-B8-II Interest in reduction of the
principal balance thereof, if any, to zero.

THE CERTIFICATES

The following table specifies the Class designation, Certificate Interest Rate,
initial Class Principal Amount or Class Notional Amount, and minimum
denomination (by dollar amount or Percentage Interest) for each Class of
Certificates representing the interests in the Trust Fund created hereunder.
Each Group I Certificate (other than the Class R Certificates) represents
ownership of a regular interest in REMIC I-4 for purposes of the REMIC
provisions. Each Group II Certificate represents ownership of one or more
regular interests in REMIC II-2 for purposes of the REMIC provisions.

                                       10
<PAGE>

<TABLE>
<CAPTION>
                                          Initial Class
                                        Principal Amount
                     Certificate            or Class
Class Designation   Interest Rate       Notional Amount      Minimum Denomination
-----------------   -------------       ---------------      --------------------
<S>                 <C>                 <C>                  <C>
 Class 1-A1              (1)            $   224,367,000           $   25,000
 Class 1-A2              (1)            $     8,102,000           $   25,000
 Class 2-A               (2)            $   168,698,000           $   25,000
 Class 3-A1            5.12%(3)         $   185,241,000           $   25,000
 Class 3-A2            5.12%(3)         $    14,455,000           $   25,000
 Class 3-AX            5.12%(4)         $   6,932,730(4)          $1,000,000
 Class 3-PAX           5.12%(4)         $   7,086,778(4)          $1,000,000
 Class 4-A               (5)            $    98,825,000           $   25,000
 Class 5-A               (6)            $    43,550,000           $   25,000
 Class 6-A1              (7)            $    45,000,000           $   25,000
 Class 6-A2              (7)            $    71,800,000           $   25,000
 Class 6-A3              (7)            $     5,783,000           $   25,000
 Class 6-AX1             (8)            $ 122,583,000(8)          $1,000,000
 Class 6-AX2             (9)            $ 122,583,000(9)          $1,000,000
 Class B1-I             (10)            $    25,901,000           $  100,000
 Class B2-I             (10)            $     9,561,000           $  100,000
 Class B3-I             (10)            $     3,185,000           $  100,000
 Class B4-I             (10)            $     2,388,000           $  100,000
 Class B5-I             (10)            $     3,982,000           $  250,000
 Class B6-I             (10)            $     4,779,000           $  250,000
 Class B7-I             (10)            $     4,007,025           $  250,000
 Class B1-II            (11)            $     2,980,000           $  100,000
 Class B2-II            (12)            $       860,000           $  100,000
 Class B3-II            (13)            $     2,052,000           $  100,000
 Class B4-II            (14)            $     1,059,000           $  100,000
 Class B5-II            (15)            $       794,000           $  100,000
 Class B6-II            (15)            $       927,000           $  250,000
 Class B7-II            (15)            $       662,000           $  250,000
 Class B8-II            (15)            $       534,371           $  250,000
 Class BX-II            (16)            $  6,951,000(17)          $1,000,000
 Class R                 (1)            $           100           $      100
 Class P-I              (17)                        (17)                  25%
 Class P-II             (18)                        (18)                  25%
 Class P-III            (19)                        (19)                  25%
</TABLE>

---------------------------

(1)   For any Distribution Date, the Certificate Interest Rate on the
      Class 1-A1, Class 1-A2 and Class R Certificates shall be a per annum rate
      equal to the Net WAC for Pool 1 for such Distribution Date.

(2)   For any Distribution Date, the Certificate Interest Rate on the
      Class 2-A Certificates shall be a per annum rate equal to the Net WAC for
      Pool 2 for such Distribution Date.

(3)   For any Distribution Date on or prior to November 2009, the
      Certificate Interest Rate on the Class 3-A1 and Class 3-A2 Certificates
      shall be a per annum rate equal to 5.12%%; provided, however, that with
      respect to any Distribution Date as to which the Pool 3 Adjusted Net WAC
      is less than 5.12%, the Certificate Interest Rate for the Class 3-A1 and
      Class 3-A2 Certificates shall equal the Pool 3 Adjusted Net WAC for such
      Distribution Date. Beginning with the Distribution Date in December 2009,
      the Certificate

                                       11
<PAGE>

      Interest Rate on the Class 3-A1 and Class 3-A2 Certificates shall be a per
      annum rate equal to the Net WAC for Pool 3 for such Distribution Date.

(4)   The Class 3-AX and Class 3-PAX Certificates are Notional
      Certificates. For any Distribution Date, the Certificate Interest Rate for
      the Class 3-AX and Class 3-PAX Certificates for each Distribution Date on
      or prior to November 2009 will be an annual rate equal to 5.12%.
      Thereafter, the Class 3-AX and Class 3-PAX Certificates will not accrue
      interest and will not be entitled to any distributions related to
      subsequent Distribution Dates. For any Distribution Date on or prior to
      the Distribution Date in November 2009, the Class Notional Amount of the
      Class 3-AX Certificates shall be equal to the product of (i) a fraction,
      the numerator of which is the excess, if any, of (1) the weighted average
      of the Net Mortgage Rates of the Pool 3 AX Mortgage Loans at the beginning
      of the related Due Period based on their Scheduled Principle Balances as
      of the beginning of the related Due period over (2) 5.12%, and the
      denominator of which is 5.12% and (ii) the total Scheduled Principal
      Balance of the Pool 3 AX Mortgage Loans as of the beginning of the related
      Due Period. For any Distribution Date on or prior to the Distribution Date
      in November 2009, the Class Notional Amount of the Class 3-PAX
      Certificates shall be equal to the product of (i) a fraction, the
      numerator of which is the excess, if any, of (1) the weighted average of
      the Net Mortgage Rates of the Pool 3 PAX Mortgage Loans at the beginning
      of the related Due Period over (2) 5.12%, and the denominator of which is
      5.12% and (ii) the total Scheduled Principal Balance of the Pool 3 PAX
      Mortgage Loans as of the beginning of the related Due Period. Beginning
      with the Distribution Date in December 2009, the Class 3-AX and Class
      3-PAX Certificates shall have a Class Notional Amount of zero.

(5)   For any Distribution Date, the Certificate Interest Rate on the
      Class 4-A Certificates shall be a per annum rate equal to the Net WAC for
      Pool 4 for such Distribution Date.

(6)   For any Distribution Date, the Certificate Interest Rate for the
      Class 5-A Certificates shall be a per annum rate equal to the Net WAC for
      Pool 5 for such Distribution Date.

(7)   For any Distribution Date, the Certificate Interest Rate on the
      Class 6-A1, Class 6-A2 and Class 6-A3 Certificates shall be a per annum
      rate equal to the lesser of (i) LIBOR plus 0.24% and (ii) LIBOR Available
      Funds Cap for such Distribution Date.

(8)   For any Distribution Date, the Certificate Interest Rate for the
      Class 6-AX1 Certificates shall be equal to the greater of (i) (x) the Net
      WAC for Pool 6 minus (y) LIBOR plus 0.25% per annum and (ii) 0.00% per
      annum; provided, however, that solely for the first Distribution Date,
      clause (y) shall be substituted with the sum of (1) 0.01% per annum and
      (2) the product of (a) LIBOR plus 0.24% per annum and (b) a fraction, the
      numerator of which is the actual number of days in the initial Accrual
      Period for the Class 6-A1, Class 6-A2 and Class 6-A3 Certificates and the
      denominator of which is 30. For purposes of the REMIC Provisions, the
      Class 6-AX1 Certificates shall represent a specified portion of the
      interest accrued on the Class LTII1-6A Interest with such portion being
      all interest accrued on the Class LTII1-6A Interest in excess of the
      interest accrued thereon at a variable rate. Such variable rate shall be a
      per annum rate equal to (i) for the first Distribution Date, the excess of
      (x) LIBOR plus 0.25% over (y) the product of (I) LIBOR plus 0.24% and (II)
      a fraction the numerator of which is the excess of (A) 30 over (B) the
      actual number of days in the initial Accrual Period for the Class 6-A1
      Certificates and the denominator of which is 30 and (ii) for all
      subsequent Distribution Dates, LIBOR plus 0.25%. The Class 6-AX1
      Certificates are Notional Certificates. For any Distribution Date, the
      Class Notional Amount of the Class 6-AX1 Certificates will be equal to the
      Class Principal Amount of the Class 6-A1, Class 6-A2 and Class 6-A3
      Certificates immediately prior to such Distribution Date. The initial
      Class Notional Amount of the Class 6-AX1 Certificates is $122,583,000.

(9)   For any Distribution Date, the Certificate Interest Rate for the
      Class 6-AX2 Certificates shall be equal to the lesser of (i) 0.01% per
      annum and (ii) the greater of (a) 0.00% per annum and (b) the difference
      between (x) the Net WAC for Pool 6 and (y) the lesser of LIBOR plus 0.24%
      and the Net WAC for Pool 6. For purposes of the REMIC Provisions, the
      Class 6-AX2 Certificates shall represent a specified portion of the
      interest accrued on the Class LTII1-6A Interest with such portion being
      all interest accrued on the Class LTII1-6A Interest in excess of a
      variable rate. Such variable rate shall be a per annum rate equal to LIBOR
      plus 0.24%; provided, however, that such variable rate shall be subject to
      a floor equal to a per annum rate equal to the Net WAC for Pool 6 minus
      0.01%. For any Distribution Date, the Class Notional Amount of the Class
      6-AX2 Certificates will be equal to the Class Principal Amount of the
      Class 6-A1, Class 6-A2

                                       12
<PAGE>

      and Class 6-A3 Certificates immediately prior to such Distribution
      Date. The initial Class Notional Amount of the Class 6-AX2
      Certificates is $122,583,000.

(10)  For any Distribution Date, the Certificate Interest Rate for the
      Class B1-I, Class B2-I, Class B3-I, Class B4-I, Class B5-I, Class B6-I and
      Class B7-I Certificates shall be equal to an annual rate equal to the Pool
      1-5 Underlying Subordinate Rate.

(11)  The Certificate Interest Rate for the Class B1-II Certificates for
      each Distribution Date will be equal to the lesser of (i) LIBOR plus 0.47%
      per annum and (ii) the LIBOR Available Funds Cap.

(12)  The Certificate Interest Rate for the Class B2-II Certificates for
      each Distribution Date will be equal to the lesser of (i) LIBOR plus 0.52%
      per annum and (ii) the LIBOR Available Funds Cap.

(13)  The Certificate Interest Rate for the Class B3-II Certificates for
      each Distribution Date will be equal to the lesser of (i) LIBOR plus 0.77%
      per annum and (ii) the LIBOR Available Funds Cap.

(14)  The Certificate Interest Rate for the Class B4-II Certificates for
      each Distribution Date will be equal to the lesser of (i) LIBOR plus 1.30%
      per annum and (ii) the LIBOR Available Funds Cap.

(15)  For any Distribution Date, the Certificate Interest Rate for the
      Class B5-II, Class B6-II, Class B7-II and Class B8-II Certificates shall
      be an annual rate equal to the Net WAC for Pool 6 for such Distribution
      Date.

(16)  The Class BX-II Certificates are Notional Certificates comprised of
      four components: the B1X-II Component, the B2X-II Component, the B3X-II
      Component and the B4X-II Component. With respect to each Distribution Date
      and the related Accrual Period, the Class BX-II Certificates will be
      entitled to the interest accrued on each of its four components. On each
      Distribution Date, the B1X-II Component shall be entitled to current
      interest equal to the amount of interest accrued during the related
      Accrual Period on the B1X-II Component Notional Amount at the B1X-II
      Component Interest Rate. On each Distribution Date, the B2X-II Component
      shall be entitled to current interest equal to the amount of interest
      accrued during the related Accrual Period on the B2X-II Component Notional
      Amount at the B2X-II Component Interest Rate. On each Distribution Date,
      the B3X-II Component shall be entitled to current interest equal to the
      amount of interest accrued during the related Accrual Period on the B3X-II
      Component Notional Amount at the B3X-II Component Interest Rate. On each
      Distribution Date, the B4X-II Component shall be entitled to current
      interest equal to the amount of interest accrued during the related
      Accrual Period on the B4X-II Component Notional Amount at the B4X-II
      Component Interest Rate. On each Distribution Date, the Class Notional
      Amount of the Class BX-II Certificates will be equal to the sum of the
      B1X-II Component Notional Amount, the B2X-II Component Notional Amount,
      the B3X-II Component Notional Amount and the B4X-II Component Notional
      Amount. The Class Notional Amount of the Class BX-II Certificates will be
      $6,951,000 for the first Distribution Date.

(17)  The Class P-I Certificates will be entitled to receive Prepayment
      Penalty Amounts paid by borrowers upon voluntary full or partial
      prepayment of the Mortgage Loans in Pool 1, Pool 2, Pool 4 and Pool 5.

(18)  The Class P-II Certificates will be entitled to receive Prepayment
      Penalty Amounts paid by borrowers upon voluntary full or partial
      prepayment of the Mortgage Loans in Pool 3.

(19)  The Class P-III Certificates will be entitled to receive Prepayment
      Penalty Amounts paid by borrowers upon voluntary full or partial
      prepayment of the Mortgage Loans in Pool 6.

      As of the Cut-off Date, the Mortgage Loans had an aggregate Scheduled
Principal Balance of $929,492,496.62.

      For purposes hereof, each pool of Mortgage Loans constitutes a fully
separate and distinct sub-trust.

      In consideration of the mutual agreements herein contained, the Depositor,
the Master Servicer, the Securities Administrator and the Trustee hereby agree
as follows:

                                       13
<PAGE>

                                    ARTICLE I

                                   DEFINITIONS

      Section 1.01. Definitions.

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

      Accepted Servicing Practices: With respect to any Mortgage Loan, as
applicable, either (x) those customary mortgage master servicing practices of
prudent mortgage servicing institutions that 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
Securities Administrator (as successor Master Servicer) or the Master Servicer
or (y) as provided in the applicable Servicing Agreement, to the extent
applicable to the related 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.

      Accretion Directed Certificate: Not applicable.

      Accretion Termination Date: Not applicable.

      Accrual Amount: As to any Class of Accrual Certificates and each
Distribution Date through the Credit Support Depletion Date, the sum of (x) any
amount of Accrued Certificate Interest allocable to such Class pursuant to
Section 5.02(a)(i) on such Distribution Date and (y) any Interest Shortfall
allocable to such Class pursuant to Section 5.02(a)(ii) on such Distribution
Date. As to any Class of Accrual Certificates and each Distribution Date after
the Credit Support Depletion Date, zero.

      Accrual Certificate: None.

      Accrual Component: None.

      Accrual Period: With respect to any Distribution Date and any Class of
Certificates (except for the Class 6-A1, Class 6-A2, Class 6-A3 and Subordinate
LIBOR Certificates), REMIC I-1 Interests, REMIC I-2 Interests, REMIC I-3
Interests and REMIC II-1 Interests (except for the Class LTII1-B1-II Interest,
Class LTII1-B2-II Interest, Class LTII1-B3-II Interest and Class LTII1-B4-II
Interest), the one-month period beginning immediately following the end of the
preceding Accrual Period (or from the Cut-off Date, in the case of the first
Accrual Period) and ending on the last day of the month immediately preceding
the month in which such Distribution Date occurs. In the case of the Class 6-A1,
Class 6-A2, Class 6-A3 and Subordinate LIBOR Certificates and the Class
LTII1-B1-II Interest, Class LTII1-B2-II Interest, Class LTII1-B3-II Interest and
Class LTII1-B4-II Interest, the Accrual Period will be the period from and
including the preceding Distribution Date (or, in the case of the first
Distribution Date, from February 28, 2005 in the case of the Class 6-A1, Class
6-A2 and Class 6-A3 Certificates or from February 25, 2005 in the case of the
Subordinate LIBOR Certificates and the Class LTII1-B1-II

                                       14
<PAGE>

Interest, Class LTII1-B2-II Interest, Class LTII1-B3-II Interest and Class
LTII1-B4-II Interest) to and including the day prior to such Distribution Date.

      Accrued Certificate Interest: As to any Class of Certificates (other than
the Class 3-AX, Class 3-PAX, Class 6-AX1, Class 6-AX2, and Class BX-II
Certificates) and any Distribution Date, the amount of interest accrued during
the related Accrual Period on the related Class Principal Amount immediately
prior to that Distribution Date or, in the case of the Class 3-AX, Class 3-PAX,
Class 6-AX1, Class 6-AX2 Certificates and each Component, the related Class
Notional Amount or Component Notional Amount for that Distribution Date at the
applicable Certificate Interest Rate or Component Interest Rate, as reduced by
such Class's or Component's share of the interest portion of (i) any Excess
Losses for the related Mortgage Pool or Mortgage Pools for such Distribution
Date and (ii) any Relief Act Reduction for the related Mortgage Pool or Mortgage
Pools for such Distribution Date, in each case allocable among the Senior
Certificates of the related Certificate Group and the related Subordinate
Certificates (or each Component in the case of the Class BX-II Certificates)
proportionately based on (1) in the case of the Senior Certificates and the
Group II Subordinate Certificates, the Accrued Certificate Interest otherwise
distributable thereon, and (2) in the case of the Group I Subordinate
Certificates interest accrued (at the Underlying Subordinate Rate for the
relevant Mortgage Pool) on their respective Apportioned Principal Balances. All
calculations of interest on each Class of Certificates (other than the
Subordinate LIBOR Certificates) and each of the REMIC I-1 Interests, REMIC I-2
Interests, REMIC I-3 Interests and REMIC II-I Interests (other than the Class
LTII1-B1-II Interest, Class LTII1-B2-II Interest, Class LTII1-B3-II Interest and
Class LTII1-B4-II Interest) shall be calculated on the basis of a 360-day year
consisting of twelve 30-day months. All calculations of interest on the
Subordinate LIBOR Certificates and the Class LTII1-B1-II Interest, Class
LTII1-B2-II Interest, Class LTII1-B3-II Interest and Class LTII1-B4-II Interest
will be made on the basis of a 360-day year and the actual number of days
elapsed in the applicable Accrual Period. The Accrued Certificate Interest with
respect to the Class BX-II Certificates shall be the sum of the Accrued
Certificate Interest with respect to each Component. The interest shall accrue
during the related Accrual Period. Act: As defined in Section 3.03(c).

      Additional Collateral: None.

      Additional Collateral Servicing Agreement: None.

      Advance: An advance of the aggregate of payments of principal and interest
(net of the Retained Interest Rate (if applicable), the Master Servicing Fee and
the applicable Servicing Fee) on one or more Mortgage Loans that were due on the
Due Date in the related Due Period and not received as of the close of business
on the related Determination Date, required to be made by or on behalf of the
Master Servicer and the related Servicer (or by the Securities Administrator
solely in its capacity as successor Master Servicer in accordance with Section
6.14) pursuant to Section 5.04.

      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

                                       15
<PAGE>

ownership of voting securities, by contract or otherwise; and the terms
"controlling" and "controlled" have meanings correlative to the foregoing.

      Aggregate Master Servicing Compensation: Not applicable.

      Aggregate Principal Balance: The aggregate of the Scheduled Principal
Balances for all Mortgage Loans at any date of determination.

      Aggregate Subordinate Percentage: With respect to any Distribution Date,
the sum of the Class Principal Amounts of the Group I Subordinate Certificates
immediately prior to such date divided by the sum of the Pool Balances for all
of the Mortgage Pools in Mortgage Group I for the immediately preceding
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.

      AP Percentage: Not applicable.

      AP Principal Distribution Amount: Not applicable.

      Applicants: As defined in Section 8.02(b).

      Apportioned Principal Balance: As to any Class of Group I Subordinate
Certificates and any Distribution Date, the Class Principal Amount of such Class
immediately prior to such Distribution Date multiplied by a fraction, the
numerator of which is the applicable Group Subordinate Amount for such date and
the denominator of which is the sum of the Group Subordinate Amounts for each
Mortgage Pool in Mortgage Group I for such date.

      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.

      Associated Mortgage Loan: Not applicable.

      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 the Trustee shall not
be responsible for determining whether any such assignment is in recordable
form.

      Aurora: Aurora Loan Services LLC or its successor in interest, in its
capacity as a Servicer.

                                       16
<PAGE>

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

      Authorized Officer: Not applicable.

      Available Distribution Amount: As to each Mortgage Pool and on any
Distribution Date, the sum of the

following amounts:

            (i) the total amount of all cash received by the Master Servicer
      through the Remittance Date applicable to each Servicer and deposited with
      the Securities Administrator by the Master Servicer by the Deposit Date
      for such Distribution Date on the Mortgage Loans of such Mortgage Pool
      (including proceeds of any Insurance Policy and any other credit support
      relating to such Mortgage Loans and including any Subsequent Recovery),
      plus all Advances made by the Master Servicer or any Servicer (or the
      Securities Administrator, solely in its capacity as successor Master
      Servicer) for such Distribution Date, any Compensating Interest Payment
      for such date and Mortgage Pool, any amounts received with respect to any
      Additional Collateral, if any, or any surety bond, if any, related thereto
      and any amounts paid by any Servicer in respect of Prepayment Interest
      Shortfalls in respect of the related Mortgage Loans for such date, but not
      including:

            (A) all amounts distributed pursuant to Section 5.02 on prior
      Distribution Dates;

            (B) all Scheduled Payments of principal and interest collected but
      due on a date subsequent to the related Due Period;

            (C) all Principal Prepayments received or identified by the
      applicable Servicer after the applicable Prepayment Period (together with
      any interest payments received with such prepayments to the extent that
      they represent the payment of interest accrued on the related Mortgage
      Loans for the period subsequent to the applicable Prepayment Period);

            (D) any other unscheduled collection, including Net Liquidation
      Proceeds, Subsequent Recoveries and Insurance Proceeds, received by the
      Master Servicer after the applicable Prepayment Period;

            (E) all fees and amounts due or reimbursable to the Master Servicer,
      the Trustee (or its custodian) , the Securities Administrator, the
      Custodian or a Servicer pursuant to the terms of this Agreement, the
      applicable Custodial Agreement or the applicable Servicing Agreement;

            (F) [Reserved];

            (G) [Reserved];

            (H) Prepayment Interest Excess, to the extent not offset by
      Prepayment Interest Shortfalls; and

                                       17
<PAGE>

            (ii) any other payment made by the Master Servicer, any Servicer,
      the Securities Administrator, the Trustee, the Seller, the Depositor, or
      any other Person with respect to such Distribution Date (including the
      Purchase Price with respect to any Mortgage Loan purchased by the Seller,
      the Depositor or any other Person).

      B1X-II Component: One of the four components of the Class BX-II
Certificates.

      B1X-II Component Interest Rate: With respect to each Distribution Date,
the excess, if any, of (x) the Net WAC for Pool 6 for such Distribution Date
over (y) the product of (i) the Certificate Interest Rate on the Class B1-II
Certificates for such Distribution Date and (ii) a fraction the numerator of
which is the actual number of days in the related Accrual Period for the Class
B1-II Certificates and the denominator of which is 30.

      B1X-II Component Notional Amount: The Class Principal Amount of the Class
B1-II Certificates immediately prior to the Distribution Date.

      B2X-II Component: One of the four components of the Class BX-II
Certificates.

      B2X-II Component Interest Rate: With respect to each Distribution Date,
the excess, if any, of (x) the Net WAC for Pool 6 for such Distribution Date
over (y) the product of (i) the Certificate Interest Rate on the Class B2-II
Certificates for such Distribution Date and (ii) a fraction the numerator of
which is the actual number of days in the related Accrual Period for the Class
B2-II Certificates and the denominator of which is 30.

      B2X-II Component Notional Amount: The Class Principal Amount of the Class
B2-II Certificates immediately prior to the Distribution Date.

      B3X-II Component: One of the four components of the Class BX-II
Certificates.

      B3X-II Component Interest Rate: With respect to each Distribution Date,
the excess, if any, of (x) the Net WAC for Pool 6 for such Distribution Date
over (y) the product of (i) the Certificate Interest Rate on the Class B3-II
Certificates for such Distribution Date and (ii) a fraction the numerator of
which is the actual number of days in the related Accrual Period for the Class
B3-II Certificates and the denominator of which is 30.

      B3X-II Component Notional Amount: The Class Principal Amount of the Class
B3-II Certificates immediately prior to the Distribution Date.

      B4X-II Component: One of the four components of the Class BX-II
Certificates.

      B4X-II Component Interest Rate: With respect to each Distribution Date,
the excess, if any, of (x) the Net WAC for Pool 6 for such Distribution Date
over (y) the product of (i) the Certificate Interest Rate on the Class B4-II
Certificates for such Distribution Date and (ii) a fraction the numerator of
which is the actual number of days in the related Accrual Period for the Class
B4-II Certificates and the denominator of which is 30.

      B4X-II Component Notional Amount: The Class Principal Amount of the Class
B4-II Certificates immediately prior to the Distribution Date.

                                       18
<PAGE>

      Balloon Mortgage Loan: Not applicable.

      Balloon Payment: None.

      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 United States Bankruptcy Code of 1986, as amended, or
any other similar state laws.

      Bankruptcy Coverage Termination Date: As to any Mortgage Pool, the
Distribution Date on which the Bankruptcy Loss Limit has been reduced to zero
(or less than zero).

      Bankruptcy Loss Limit: As of the Cut-off Date, $304,050 for Pools 1
through 5 and $100,000 for Pool 6, each such amount shall be reduced from time
to time by the amount of Bankruptcy Losses in the related Pool or Pools that are
allocated to the Certificates.

      Bankruptcy Losses: With respect to the Mortgage Loans in the related
Mortgage Pool, losses that are incurred as a result of Deficient Valuations and
any reduction, in a bankruptcy proceeding, of the amount of the Scheduled
Payment on a Mortgage Loan other than as a result of a Deficient Valuation.

      Basis Risk Shortfall: For any Distribution Date on or prior to the
Distribution Date in November 2009, to the extent that the interest distributed
on the Class 3-A1, Class 3-A2, Class B1-I, Class B2-I, Class B3-I, Class B4-I,
Class B5-I, Class B6-I and Class B7-I Certificates is limited due to either the
weighted average Net Mortgage Rate on the Pool 3 AX Mortgage Loans or the
weighted average Net Mortgage Rate on the Pool 3 PAX Mortgage Loans being below
5.12%, the amount of any such shortfall.

      Blanket Mortgage: Not applicable.

      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, all of the Classes of Certificates listed in the table in the Preliminary
Statement entitled "The Certificates", other than the Class R and Class P
Certificates, will constitute Book-Entry Certificates.

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

                                       19
<PAGE>

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

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

      Certificate Group: The Group 1 Certificates, the Group 2 Certificates, the
Group 3 Certificates, the Group 4 Certificates, the Group 5 Certificates or the
Group 6 Certificates, as applicable.

      Certificate Interest Rate: With respect to each Class of Certificates and
any Distribution Date, the applicable per annum rate specified or determined as
provided 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
Notional Certificate, at the time of determination, the maximum specified dollar
amount of principal to which the Holder thereof is then entitled hereunder, such
amount being equal to the initial principal amount set forth on the face of such
Certificate (plus, in the case of any Negative Amortization Certificate, any
Deferred Interest allocated thereto on previous Distribution Dates, and plus, in
the case of any Accrual Certificate, its Percentage Interest of any related
Accrual Amount for each previous Distribution Date), less the amount of all
principal distributions previously made with respect to such Certificate, and
all Realized Losses allocated to such Certificate and, in the case of a
Subordinate Certificate, any Subordinate Certificate Writedown Amount allocated
to such Certificates; provided, however, that on any Distribution Date on which
a Subsequent Recovery for a Mortgage Pool is distributed, the Certificate
Principal Amount of any Class of related Certificates then outstanding for which
any Realized Loss or any Subordinate Certificate Writedown Amount has been
applied will be increased, in order of seniority, by an amount equal to the
lesser of (i) the amount the Class of Certificates has been reduced by any
Realized Losses or any Subordinate Certificate Writedown Amount which have not
been previously offset by any Subsequent Recovery pursuant to this proviso and
(ii) the total amount of any Subsequent Recovery for such Mortgage Pool
distributed on such date to Certificateholders (as reduced (x) by increases in
the Certificate Principal Amount of more senior Classes of Certificates related
to such Mortgage Pool on such Distribution Date and (y) to reflect a
proportionate amount of what would (but for this clause (y) have been the
increases in the Certificate Principal Amount of Classes of Certificates related
to such Mortgage Pool of equal seniority on such Distribution Date). For
purposes of Article V hereof, unless specifically provided to the contrary,
Certificate Principal Amounts shall be determined as of the close of business of
the immediately preceding Distribution Date, after giving effect to all
distributions made on such date. Notional Certificates are issued without
Certificate Principal Amounts.

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

                                       20
<PAGE>

      Class: All Certificates bearing the same class designation, and, in the
case of REMIC I-1, REMIC I-2, REMIC I-3 or REMIC II-1, all interests bearing the
same designation.

      Class AP Certificate: None.

      Class AP Deferred Amount: Not applicable.

      Class B Certificate: Any Class B1-I, Class B2-I, Class B3-I, Class B4-I,
Class B5-I, Class B6-I, Class B7-I, Class B1-II, Class B2-II, Class B3-II, Class
B4-II, Class B5-II, Class B6-II, Class B7-II, Class B8-II or Class BX-II
Certificate.

      Class BX-II Notional Amount: The sum of the Component Notional Amounts of
the Components.

      Class Notional Amount: With respect to each Class of Notional Certificates
the applicable class notional amount calculated as provided in the Preliminary
Statement hereto.

      Class P Certificate: Any Class P-I, Class P-II or Class P-III
Certificates.

      Class Percentage: With respect to each Class of Subordinate Certificates,
for each Distribution Date, the percentage obtained by dividing the Class
Principal Amount of such Class immediately prior to such Distribution Date by
the sum of the Class Principal Amounts of all Certificates related to the same
Mortgage Group immediately prior to such date.

      Class Principal Amount: With respect to each Class of Certificates other
than any Class of Notional Certificates, the aggregate of the Certificate
Principal Amounts of all Certificates of such Class at the date of
determination. With respect to each Class of Notional Certificates and the Class
P Certificates, zero.

      Clearing Agency: An organization registered as a "clearing agency"
pursuant to Section 17A of the Securities Exchange Act of 1934, as amended. As
of the Closing Date, the Clearing Agency shall be The Depository Trust Company.

      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, societe anonyme, and any successor
thereto.

      Closing Date: February 28, 2005.

      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.

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

                                       21
<PAGE>

      Commission: As defined in Section 6.20(a).

      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 Servicers with respect to such Distribution Date. The
Master Servicer shall not be responsible to make any Compensating Interest
Payment.

      Component: Any of the B1X-II Component, the B2X-II Component, the B3X-II
Component and the B4X-II Component.

      Component Certificate: The Class BX-II Certificates.

      Component Interest Rate: Any of the B1X-II Component Interest Rate, the
B2X-II Component Interest Rate.

the B3X-II Component Interest Rate or the B4X-II Component Interest Rate.

      Component Notional Amount: Any of the B1X-II Component Notional Amount,
the B2X-II Component Notional Amount, the B3X-II Component Notional Amount or
the B4X-II Component Notional Amount.

      Component Principal Amount: Not applicable.

      Component Writedown Amount: Not applicable.

      Conventional Loan: A Mortgage Loan that is not insured by the United
States Federal Housing Administration or guaranteed by the United States
Veterans Administration.

      Converted Mortgage Loan: Not applicable.

      Convertible Mortgage Loan: Not applicable.

      Cooperative Corporation: The entity that holds title (fee or an acceptable
leasehold estate) to the real property and improvements constituting the
Cooperative Property and which governs the Cooperative Property, which
Cooperative Corporation must qualify as a Cooperative Housing Corporation under
Section 216 of the Code.

      Cooperative Loan: Any Mortgage Loan secured by Cooperative Shares and a
Proprietary Lease.

      Cooperative Loan Documents: As to any Cooperative Loan, (i) the
Cooperative Shares, together with a stock power in blank; (ii) the original
executed Security Agreement and the assignment of the Security Agreement
endorsed in blank; (iii) the original executed Proprietary Lease and the
assignment of the Proprietary Lease endorsed in blank; (iv) the original
executed Recognition Agreement and the assignment of the Recognition Agreement
(or a blanket assignment of all Recognition Agreements) endorsed in blank; (v)
the executed UCC-1 financing statement with evidence of recording thereon, which
has been filed in all places required to perfect the security interest in the
Cooperative Shares and the Proprietary Lease; and (vi) executed UCC-3 financing
statements (or copies thereof) or other appropriate UCC financing

                                       22
<PAGE>

statements required by state law, evidencing a complete and unbroken line from
the mortgagee to the Trustee with evidence of recording thereon (or in a form
suitable for recordation).

      Cooperative Property: The real property and improvements owned by the
Cooperative Corporation, that includes the allocation of individual dwelling
units to the holders of the Cooperative Shares of the Cooperative Corporation.

      Cooperative Shares: Shares issued by a Cooperative Corporation.

      Cooperative Unit: A single-family dwelling located in a Cooperative
Property.

      Corporate Trust Office: With respect to the Trustee, the principal
corporate trust office of the Trustee located at 452 Fifth Avenue, New York, New
York 10018, Attention: SARM 2005-4, or at such other address as the Trustee may
designate from time to time by notice to the Certificateholders, the Depositor,
the Master Servicer and the Securities Administrator or the principal corporate
trust office of any successor Trustee. With respect to the Securities
Administrator for purposes of presentment of Certificates for registration of
transfer, exchange or final payment, Wells Fargo Bank, National Association,
Sixth Street and Marquette Avenue, Minneapolis, Minnesota 55479, Attention: SARM
2005-4.

      Corresponding Certificates or Components: With respect to any class of
REMIC II-1 Interests, the Class or Classes of Certificates or Components so
designated in the Preliminary Statement hereto.

      Corresponding Class: Not applicable.

      Credit Score: With respect to any Mortgage Loan, a numerical assessment of
default risk with respect to the Mortgagor under such Mortgage Loan, determined
on the basis of a methodology developed by Fair, Isaac & Co., Inc.

      Credit Support Depletion Date: The Distribution Date on which, after
giving effect to all distributions on such date, the aggregate Certificate
Principal Amount of the Group I Subordinate Certificates is reduced to zero.

      Credit Support Percentage: As to any Class of Subordinate Certificates and
any Distribution Date, the sum of the Class Percentages of all Classes of
Certificates that rank lower in priority than such Class.

      Custodial Agreement: Each custodial agreement attached as Exhibit K
hereto, and any custodial agreement subsequently executed by the Trustee
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, U.S. Bank National Association and Wells Fargo Bank, N.A.

      Cut-off Date: February 1, 2005.

      Cut-off Date Aggregate Principal Balance: Not applicable.

                                       23
<PAGE>

      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 any proceeding under Bankruptcy law or any similar
proceeding.

      Deferred Interest: None.

      Deficient Valuation: With respect to any Mortgage Loan, a valuation by a
court of competent jurisdiction of the Mortgaged Property in an amount less than
the then outstanding indebtedness under such Mortgage Loan, which valuation
results from a proceeding under Bankruptcy law or any similar proceeding.

      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.

      Deposit Date: With respect to each Distribution Date, the Business Day
immediately preceding such Distribution Date.

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

      Designated Rate: Not applicable.

      Determination Date: With respect to each Distribution Date, the Remittance
Date immediately preceding such Distribution Date.

      Direct Obligations: As defined in the definition of Eligible Investments.

      Discount Mortgage Loan: None.

      Disqualified Organization: Either (i) the United States, (ii) any state or
political subdivision thereof, (iii) any foreign government, (iv) any
international organization, (v) any agency or instrumentality of any of the
foregoing, (vi) any tax-exempt organization (other than a cooperative described
in section 521 of the Code) which is exempt from the tax imposed by Chapter 1 of
the Code unless such organization is subject to the tax imposed by section 511
of the Code, (vii) any organization described in section 1381(a)(2)(C) of the
Code, (viii) any "electing large partnership" described in section 775 of the
Code, or (ix) any other entity designated as a Disqualified Organization by
relevant legislation amending the REMIC Provisions and in effect at or proposed
to be effective as of the time of the determination. In addition, a corporation
will not be treated as an instrumentality of the United States or of any state
or political subdivision thereof if all of its activities are subject to tax
and, with the exception of the Federal Home Loan Mortgage Corporation, a
majority of its board of directors is not selected by such governmental unit.

                                       24
<PAGE>

      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 March 2005.

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

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

      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, the Securities Administrator 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 or the Securities Administrator,
      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;

                                       25
<PAGE>

            (iii) repurchase agreements collateralized by Direct Obligations or
      securities guaranteed by GNMA, FNMA or FHLMC with any registered
      broker/dealer subject to Securities Investors' 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 one of the two highest short-term credit
      ratings of each 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 Aggregate Principal 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 either Rating Agency;

            (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 ratings;

            (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 fund, common trust fund or
      time deposit or obligation, or interest-bearing or other security or
      investment (including those managed or advised by the Securities
      Administrator or an Affiliate thereof), (A) rated in the highest rating
      category by each Rating Agency (if rated by such Rating Agency) or (B)
      that would not adversely affect the then current rating by either 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 for which the
      Trustee, the Securities Administrator, the Master Servicer or an affiliate
      thereof serves as an investment advisor, administrator, shareholder
      servicing agent, and/or custodian or subcustodian, notwithstanding that
      (i) any such Person or an Affiliate thereof charges and collects fees and
      expenses from such funds for services rendered, (ii) any such Person or an
      Affiliate thereof charges and collects fees and expenses for services
      rendered pursuant to this Agreement, and (iii) services performed for such
      funds and pursuant to this Agreement may converge

                                       26
<PAGE>

      at any time. The Trustee specifically authorizes any such Person or an
      Affiliate thereof to charge and collect from the Trust Fund 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 (x) 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 and (y) each such investment must
be a "permitted investment" within the meaning of Section 860G(a)(5) of the
Code.

      Employee Mortgage Loan: None.

      ERISA: The Employee Retirement Income Security Act of 1974, as amended,
and as it may be further amended from time to time, any successor statutes
thereto, and applicable U.S. Department of Labor regulations issued pursuant
thereto in temporary or final form.

      ERISA-Qualifying Underwriting: A best efforts or firm commitment
underwriting or private placement that would satisfy the requirements of the
Underwriter's Exemption, except, in relevant part, for the requirement that the
certificates have received a rating at the time of acquisition that is in one of
the three (or four, in the case of a "designated transaction") highest generic
rating categories by at least one of the Rating Agencies.

      ERISA-Restricted Certificate: Any Class R, Class P, Class B5-I, Class
B6-I, Class B7-I, Class B6-II, Class B7-II or Class B8-II Certificate and any
other Certificate, unless the acquisition and holding of such other Certificate
is covered by and exempt under the Underwriter's Exemption.

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

      Euroclear: Euroclear 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).

      Excess Loss: Any Bankruptcy Loss, or portion thereof, in excess of the
then-applicable Bankruptcy Loss Limit, any Fraud Loss, or portion thereof, in
excess of the then-applicable Fraud Loss Limit, and any Special Hazard Loss, or
portion thereof, in excess of the then-applicable Special Hazard Loss Limit.

      Extended Period: As defined in Section 10.04(b).

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

                                       27
<PAGE>

      FHLMC: 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.

      Final Scheduled Distribution Date: For the Certificates (other than the
Class 3-AX and Class 3-PAX Certificates), the Distribution Date in March 2035;
for the Class 3-AX and Class 3-PAX Certificates, the Distribution Date in
November 2009.

      Financial Intermediary: Not applicable.

      Fitch: Not applicable.

      FNMA: 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.

      Form 10-K Certification: As defined in Section 6.20(a) hereof.

      Fraud Loss: Any Realized Loss on a Liquidated Mortgage Loan sustained by
reason of a default arising from fraud, dishonesty or misrepresentation in
connection with the related Mortgage Loan, as reported by the applicable
Servicer to the Master Servicer.

      Fraud Loss Limit: With respect to any Distribution Date (x) prior to the
first anniversary of the Cut-off Date, (i) $15,940,822 for Pools 1 through 5 and
(ii) $2,649,027 for Pool 6, less the aggregate of Fraud Losses in the related
Pool or Pools since the Cut-off Date and (y) from the first anniversary to the
fifth anniversary of the Cut-off Date, an amount equal to (1) the lesser of (a)
the applicable Fraud Loss Limit as of the most recent anniversary of the Cut-off
Date and (b) 1% of the aggregate principal balance of all the Mortgage Loans in
the related Pool or Pools as of the most recent anniversary of the Cut-off Date
less (2) the aggregate of Fraud Losses in the related Pool or Pools since the
most recent anniversary of the Cut-off Date. On or after the fifth anniversary
of the Cut-off Date, the Fraud Loss Limit shall be zero.

      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.

      Grantor Trust: Any of Grantor Trust I, Grantor Trust II, Grantor Trust III
or any grantor trust described in Section 10.01 hereof.

      Grantor Trust I: That certain "grantor trust" (within the meaning of the
Grantor Trust Provisions) consisting of the Grantor Trust I Assets.

      Grantor Trust I Assets: Any Prepayment Penalty Amounts collected with
respect to Pool 1, Pool 2, Pool 4 or Pool 5.

      Grantor Trust II: That certain "grantor trust" (within the meaning of the
Grantor Trust Provisions) consisting of the Grantor Trust II Assets.

                                       28
<PAGE>

      Grantor Trust II Assets: Any Prepayment Penalty Amounts collected with
respect to Pool 3.

      Grantor Trust III: That certain "grantor trust" (within the meaning of the
Grantor Trust Provisions) consisting of the Grantor Trust III Assets.

      Grantor Trust III Assets: Any Prepayment Penalty Amounts collected with
respect to Pool 6.

      Grantor Trust Provisions: Subpart E of Subchapter J of the Code, including
Treasury regulation section 301.7701-4(c)(2).

      Group 1: All of the Group 1 Certificates.

      Group 1 Certificate: Any Class 1-A1, Class 1-A2 or Class R Certificate.

      Group 2: All of the Group 2 Certificates.

      Group 2 Certificate: Any Class 2-A Certificate.

      Group 3: All of the Group 3 Certificates.

      Group 3 Certificate: Any Class 3-A1, Class 3-A2, Class 3-AX or Class 3-PAX
Certificate.

      Group 4: All of the Group 4 Certificates.

      Group 4 Certificate: Any Class 4-A Certificate.

      Group 5: All of the Group 5 Certificates.

      Group 5 Certificate: Any Class 5-A Certificate.

      Group 6: All of the Group 6 Certificates.

      Group 6 Certificate: Any Class 6-A1, Class 6-A2, Class 6-A3, Class 6-AX1
or Class 6-AX2 Certificate.

      Group I Certificate: Any of the Class 1-A1, Class 1-A2, Class 2-A, Class
3-A1, Class 3-A2, Class 3-AX, Class 3-PAX, Class 4-A, Class 5-A, Class B1-I,
Class B2-I, Class B3-I, Class B4-I, Class B5-I, Class B6-I, Class B7-I or Class
R Certificates.

      Group I Subordinate Certificate: Any of the Class B1-I, Class B2-I, Class
B3-I, Class B4-I, Class B5-I, Class B6-I or Class B7-I Certificates.

      Group II Certificate: Any of the Class 6-A1, Class 6-A2, Class 6-A3, Class
6-AX1, Class 6-AX2, Class B1-II, Class B2-II, Class B3-II, Class B4-II, Class
B5-II, Class B6-II, Class B7-II, Class B8-II or Class BX-II Certificates.

                                       29
<PAGE>

      Group II Subordinate Certificate: Any of the Class B1-II, Class B2-II,
Class B3-II Class B4-II, Class B5-II, Class B6-II, Class B7-II, Class B8-II or
Class BX-II Certificates.

      Group Subordinate Amount: With respect to any Mortgage Pool and any
Distribution Date, the excess, if any, of the Pool Balance of such Mortgage Pool
for the immediately preceding Distribution Date (or in the case of the first
Distribution Date, the aggregate Scheduled Principal Balance of the Mortgage
Loans in such Mortgage Pool as of the Cut-off Date) over the sum of the
aggregate of the Certificate Principal Amounts of the Senior Certificates of the
related Certificate Group immediately prior to the related Distribution Date.

      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, any Servicer, or any Affiliate thereof 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 or any Servicer in determining whether any
Certificates are registered to an Affiliate of the Depositor, the Master
Servicer or such Servicer, respectively.

      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 Securities and Exchange
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, and (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.

      Initial LIBOR Rate: 2.65% per annum.

      Initial Net Mortgage Rate: Not applicable.

      Initial Senior Enhancement Percentage: 6.75% for Mortgage Group I and
7.45% for Mortgage Group II.

      Insurance Policy: Any Primary Mortgage Insurance Policy and 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
applicable Servicer in connection with procuring such proceeds, (ii) to be
applied to restoration or repair of the related Mortgaged

                                       30
<PAGE>

Property or (iii) required to be paid over to the Mortgagor pursuant to law or
the related Mortgage Note.

      Interest Distribution Amount: Not applicable.

      Interest Shortfall: With respect to any Class of Certificates and any
Distribution Date, any Accrued Certificate Interest not distributed (or added to
principal) with respect to any previous Distribution Date, other than any Net
Prepayment Interest Shortfalls.

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

      IRS: The Internal Revenue Service.

      Latest Possible Maturity Date: The Distribution Date in March 2035.

      Lehman Brothers Holdings: 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, the per annum rate determined
pursuant to Section 4.05 on the basis of London interbank offered rate
quotations for one month Eurodollar deposits, as such quotations may appear on
the display designated as page "LIBOR" on the Bloomberg Financial Markets
Commodities News (or such other page as may replace such page on that service
for the purpose of displaying London interbank offered quotations of major
banks).

      LIBOR Available Funds Cap: For each Distribution Date will be equal to the
Net WAC for Pool 6 for each Distribution Date and, in the case of the
Subordinate LIBOR Certificates, the LIBOR Available Funds Cap shall be
multiplied by the fraction, the numerator of which is 30 and the denominator of
which is the actual number of days in the related Accrual Period.

      LIBOR Certificate: Any Class 6-A1, Class 6-A2, Class 6-A3, Class B1-II,
Class B2-II, Class B3-II and Class B4-II Certificate.

      LIBOR Component: Not applicable.

      LIBOR Determination Date: The second London Business Day immediately
preceding the commencement of each Accrual Period with respect to any LIBOR
Certificate other than the first such Accrual Period.

      Liquidated Mortgage Loan: Any defaulted Mortgage Loan as to which the
Master Servicer or the applicable 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.

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

                                       31
<PAGE>

      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 or otherwise, or the sale of the
related Mortgaged Property (including any Additional Collateral) if the
Mortgaged Property (including such Additional Collateral) is acquired in
satisfaction of the Mortgage Loan, 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 thereof.

      London Business Day: Any day on which banks are open for dealing in
foreign currency and exchange in London, England and New York City.

      Losses: As defined in Section 10.03.

      Maintenance: Not applicable.

      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,
the Business Day immediately preceding such Distribution Date.

      Master Servicing Fee: As to any Distribution Date and each Mortgage Loan,
an amount equal to the product of the Master Servicing Fee Rate and the
Scheduled Principal Balance of such Mortgage Loan as of the first day of the
related Due Period. The Master Servicing Fee for any Mortgage Loan shall be
payable in respect of any Distribution Date solely from the interest portion of
the Scheduled Payment or other payment or recovery with respect to such Mortgage
Loan.

      Master Servicing Fee Rate: With respect to each Mortgage Loan (other than
any Participation), 0.000% 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
agent for the holder from time to time of the Mortgage Note.

      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.

                                       32
<PAGE>

      Mortgage 100(SM) Loan: Not applicable.

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

      Mortgage Group: Either of Mortgage Group I or Mortgage Group II.

      Mortgage Group I: Pool 1, Pool 2, Pool 3, Pool 4 and Pool 5, collectively.

      Mortgage Group II: Pool 6.

      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. In addition, as used herein the term
"Mortgage Loan" includes the Participations, except where otherwise specified or
where the context requires otherwise.

      Mortgage Loan Sale Agreement: The agreement, dated as of February 1, 2005,
for the sale of certain Mortgage Loans by Lehman Brothers Holdings 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. The Mortgage Loan Schedule shall include, among
other information agreed upon by the Depositor, the Master Servicer, the
applicable Servicer, the Securities Administrator and the Trustee, data fields
specifying the terms and method of calculation of any Prepayment Penalty Amount
with respect to each Mortgage Loan. The Depositor shall be responsible for
providing the Trustee, the Master Servicer and the Securities Administrator 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.

      Mortgage Pool: Any of Pool 1, Pool 2, Pool 3, Pool 4, Pool 5 or Pool 6.

      Mortgage Rate: As to any Mortgage Loan, the per annum rate at which
interest accrues on such Mortgage Loan.

      Mortgaged Property: Either of (x) 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, or (y) in the case of a Cooperative Loan, the related Cooperative
Shares and Proprietary Lease, securing the indebtedness of the Mortgagor under
the related Mortgage Loan.

      Mortgagor: The obligor on a Mortgage Note.

                                       33
<PAGE>

      Negative Amortization Certificate: None.

      Net Liquidation Proceeds: With respect to any Liquidated Mortgage Loan,
the related Liquidation Proceeds net of unreimbursed expenses incurred in
connection with liquidation or foreclosure and unreimbursed Advances, Servicing
Advances and Servicing Fees 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 sum of the applicable Master Servicing Fee Rate,
Servicing Fee Rate, Securities Administrator Fee Rate, the Retained Interest
Rate (if applicable) and any mortgage insurance premium rate (if applicable).

      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 in such Mortgage Pool for such date over the sum
of any amounts paid by the applicable Servicer with respect to such shortfalls
and any amount that is required to be paid by the Master Servicer in respect of
such shortfalls pursuant to this Agreement.

      Net WAC: With respect to each Mortgage Pool and any Distribution Date, the
weighted average of Net Mortgage Rates of the Mortgage Loans in the related
Mortgage Pool at the beginning of the related Due Period, weighted on the basis
of their Scheduled Principal Balances at the beginning of the related Due
Period.

      Non-AP Percentage: Not applicable.

      Non-AP Senior Certificate: Not applicable.

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

      Non-Discount Mortgage Loan: None.

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

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

      Non-U.S. Person: Any person other than (i) a citizen or resident of the
United States; (ii) a corporation (or entity treated as a corporation for tax
purposes) created or organized in the United States or under the laws of the
United States or of any state thereof, including, for this purpose, the District
of Columbia; (iii) a partnership (or entity treated as a partnership for tax
purposes) organized in the United States or under the laws of the United States
or of any state thereof, including, for this purpose, the District of Columbia
(unless provided otherwise by future Treasury regulations); (iv) an estate whose
income is includible in gross income for United States income tax purposes
regardless of its source; or (v) a trust, if a court within the United States is
able to exercise primary supervision over the administration of the trust and
one or more U.S. Persons have authority to control all substantial decisions of
the trust. Notwithstanding the last clause of the preceding sentence, to the
extent provided in Treasury regulations, certain trusts in existence on August
20, 1996, and treated as U.S. Persons prior to such date, may elect to continue
to be U.S. Persons.

                                       34
<PAGE>

      Notional Amount: With respect to any Notional Certificate and any
Distribution Date, such Certificate's Percentage Interest of the Class Notional
Amount of such Class of Certificates for such Distribution Date.

      Notional Certificate: Any Class 3-AX, Class 3-PAX, Class 6-AX1, Class
6-AX2 or Class BX-II Certificate.

      Notional Component: None.

      Offering Document: Either of the private placement memorandum dated
February 25, 2005 relating to the Class B5-I, Class B6-I, Class B7-I, Class
B6-II, Class B7-II and Class B8-II Certificates, or the Prospectus.

      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 who may be in-house or outside counsel to
the Depositor, the Master Servicer or the applicable Servicer 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. For purpose of Section 2.01(c)(i), the Opinion of Counsel
referred to therein may take the form of a memorandum of law or other acceptable
assurance.

      Original Credit Support Percentage: With respect to any Class of
Subordinate Certificates, the Credit Support Percentage with respect to such
Class on the Closing Date.

      Original Group Subordinate Amount: As to any Mortgage Pool, the Group
Subordinate Amount for such Mortgage Pool as of the first Distribution Date.

      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.

      Parent PowerSM Loan: Not applicable.

      Participation Agreement: None.

      Participation: None.

      Participation Schedule: None.

      Participation Master Servicer: Not applicable.

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

                                       35
<PAGE>

      Permitted Transferee: As defined in Section 3.03(f).

      Percentage Interest: With respect to any Certificate and the related
Class, such Certificate's 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 Notional
Certificate, the Percentage Interest evidenced thereby shall equal the initial
Certificate Principal Amount thereof divided by the initial Class Principal
Amount of all Certificates of the same Class. With respect to any Notional
Certificate and any Class P Certificate, the Percentage Interest evidenced
thereby shall be as specified on the face thereof.

      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.

      Placement Agent: Lehman Brothers Inc.

      Plan Asset Regulations: Not applicable.

      Pledged Asset Loan-to-Value Ratio: Not applicable.

      Pledged Asset Mortgage Loan: None.

      Pool 1: The aggregate of the Mortgage Loans identified on the Mortgage
Loan Schedule as being included in Pool 1.

      Pool 1-5 Underlying Subordinate Rate: The weighted average of the
Underlying Subordinate Rate for Pool 1, Pool 2, Pool 3, Pool 4 and Pool 5,
weighted by the corresponding Group Subordinate Amounts.

      Pool 2: The aggregate of the Mortgage Loans identified on the Mortgage
Loan Schedule as being included in Pool 2.

      Pool 3: The aggregate of the Mortgage Loans identified on the Mortgage
Loan Schedule as being included in Pool 3.

      Pool 3 Adjusted Net WAC: For each Distribution Date, the weighted average,
based on their respective principal balances, of the interest rates on (1) an
obligation having a principal balance equal to the Scheduled Principal Balance
of the Pool 3 PAX Mortgage Loans at the beginning of the related Due Period and
bearing interest at a rate equal to the lesser of (x) 5.12% or (y) the weighted
average Net Mortgage Rate of the Pool 3 PAX Mortgage Loans at the beginning of
the related Due Period, weighted on the basis of their Scheduled Principal
Balances as of the beginning of the related Due Period and (2) an obligation
having a principal balance equal to the Scheduled Principal Balance of the Pool
3 AX Mortgage Loans at the beginning of the related Due Period and bearing
interest at a rate equal to the lesser of (x) 5.12% or (y) the weighted average
Net Mortgage Rate of the Pool 3 AX Mortgage Loans at the beginning of the
related Due Period , weighted on the basis of their Scheduled Principal Balances
as of the beginning of the related Due Period.

                                       36
<PAGE>

      Pool 3 AX Mortgage Loans: The Pool 3 AX Mortgage Loans are listed on
Schedule B hereto and are all of the Pool 3 Mortgage Loans other than the Pool 3
PAX Mortgage Loans.

      Pool 3 PAX Mortgage Loans: The Pool 3 PAX Mortgage Loans are listed on
Schedule C hereto and are all of the Pool 3 Mortgage Loans that have Prepayment
Penalty Amounts for which the Seller owns the servicing rights.

      Pool 4: The aggregate of the Mortgage Loans identified on the Mortgage
Loan Schedule as being included in Pool 4.

      Pool 5: The aggregate of the Mortgage Loans identified on the Mortgage
Loan Schedule as being included in Pool 5.

      Pool 6: The aggregate of the Mortgage Loans identified on the Mortgage
Loan Schedule as being included in Pool 6.

      Pool Balance: As to each Mortgage Pool and any Distribution Date, the sum
of the Scheduled Principal Balance of the Mortgage Loans included in such
Mortgage Pool.

      Prepayment Interest Excess: With respect to any Distribution Date and any
Principal Prepayment in full received on the Mortgage Loans serviced by Aurora
from the first day through the sixteenth day of the month during which such
Distribution Date occurs, all amounts paid in respect of interest at the
applicable Net Mortgage Rate on such Principal Prepayment in full.

      Prepayment Interest Shortfall: With respect to any Distribution Date and
(x) any Principal Prepayment in part and, with respect to those Mortgage Loans
serviced by Servicers other than Aurora, any Principal Prepayment in full, (y)
any Principal Prepayment in full with respect to those Mortgage Loans serviced
by Aurora if received on or after the seventeenth day of the month immediately
preceding the month of such Distribution Date but on or before the last day of
the month immediately preceding the month of such Distribution Date and (z) any
Principal Prepayment in full or in part with respect to those Mortgage Loans
serviced by Countrywide Home Loans Servicing LP if received on or after the
second day of the month immediately preceding the month of such Distribution
Date but on or before the last day of the month immediately preceding the month
of such Distribution Date, the difference between (i) one full month's interest
at the applicable Mortgage Rate (after giving effect to any applicable Relief
Act Reduction), as reduced by the applicable Servicing Fee Rate, the Master
Servicing Fee Rate and the applicable Retained Interest Rate, if any, on the
outstanding principal balance of such Mortgage Loan immediately prior to such
prepayment and (ii) the amount of interest actually received with respect to
such Mortgage Loan in connection with such Principal Prepayment.

      Prepayment Penalty Amounts: With respect to any Distribution Date, all
premiums or charges paid by the obligors under the related Mortgage Notes due to
Principal Prepayments collected by the applicable Servicer during the
immediately preceding Prepayment Period, if any.

      Prepayment Period: With respect to those Mortgage Loans serviced by
Servicers other than Aurora, any Distribution Date and any Principal Prepayment,
whether in part or in full

                                       37
<PAGE>

(including any liquidation), the calendar month immediately preceding the month
in which such Distribution Date occurs. With respect to any Distribution Date
and a Principal Prepayment in full (including any liquidation) with respect to
those Mortgage Loans serviced by Aurora, the period from the seventeenth (or, in
the case of the first Distribution Date, the first) day of the month immediately
preceding the month of such Distribution Date through the sixteenth day of the
month of such Distribution Date. With respect to those Mortgage Loans serviced
by Aurora, any Distribution Date and any Principal Prepayment in part, the
calendar month immediately preceding the month in which such Distribution Date
occurs. With respect to any Distribution Date and a Principal Prepayment in full
or in part (including any liquidation) with respect to those Mortgage Loans
serviced by Countrywide Home Loans Servicing LP, the period from the second day
of the month immediately preceding the month of such Distribution Date through
the first day of the month of such Distribution Date.

      Primary Mortgage Insurance Policy: Mortgage guaranty insurance, if any, on
an individual Mortgage Loan, as evidenced by a policy or certificate.

      Principal Amount Schedules: Not applicable.

      Principal Only Certificate: Not applicable.

      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 applicable Servicing
Agreement.

      Proceeding: Not applicable.

      Proprietary Lease: With respect to any Cooperative Unit, a lease or
occupancy agreement between a Cooperative Corporation and a holder of related
Cooperative Shares.

      Prospectus: The prospectus supplement dated February 25, 2005, together
with the accompanying prospectus dated January 25, 2005, relating to the Senior
Certificates and the Class B1-I, Class B2-I, Class B3-I, Class B4-I, Class
B1-II, Class B2-II, Class B3-II, Class B4-II, Class B5-II and Class BX-II
Certificates.

      Purchase Price: With respect to the repurchase of a Mortgage Loan pursuant
to 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
Mortgage Rate, from the date as to which interest was last paid to (but not
including) the Due Date immediately preceding the next Distribution Date, (c)
any unreimbursed Servicing Advances with respect to such Mortgage Loan and (d)
any costs and damages incurred by the Trust Fund in connection with any
violation by such Mortgage Loan of any predatory- or abusive-lending law. The
Master Servicer or the applicable Servicer (or the Securities Administrator, if
applicable) shall be reimbursed from the Purchase Price for any Mortgage Loan or
related REO Property for any Advances made with respect to such Mortgage Loan
that are reimbursable to the Master Servicer, such Servicer or the Securities
Administrator under this Agreement or the applicable Servicing Agreement, as
well as

                                       38
<PAGE>

any unreimbursed Servicing Advances and accrued and unpaid Master Servicing Fees
or Servicing Fees, as applicable.

      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:

      (a) 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;

      (b) 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;

      (c) 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;

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

      (e) 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.

      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 rating of the Certificates.

      Qualifying Substitute Mortgage Loan: In the case of a Mortgage Loan
substituted for a Deleted Mortgage Loan, a Mortgage Loan that, on the date of
substitution, (i) has a Scheduled Principal Balance (together with that of any
other mortgage loan substituted for the same Deleted Mortgage Loan) as of the
Due Date in the month in which such substitution occurs not in excess of the
Scheduled Principal Balance of the related Deleted Mortgage Loan, provided,
however, that, to the extent that the Scheduled Principal Balance of such
Mortgage Loan is less than the Scheduled Principal Balance of the related
Deleted Mortgage Loan, then such differential in principal amount, together with
interest thereon at the applicable Mortgage Rate net of the applicable Master
Servicing Fee and the applicable Servicing Fee from the date as to which

                                       39
<PAGE>

interest was last paid through the end of the Due Period in which such
substitution occurs, shall be paid by the party effecting such substitution to
the Master Servicer for deposit into the Collection Account, and shall be
treated as a Principal Prepayment hereunder; (ii) has a Net Mortgage Rate not
lower than the Net Mortgage Rate of the related Deleted Mortgage Loan and will
be a Discount Mortgage Loan if the Deleted Mortgage Loan was a Discount Mortgage
Loan or a Non-Discount Mortgage Loan if the Deleted Mortgage Loan was a
Non-Discount Mortgage Loan; (iii) has a remaining stated term to maturity not
more than eighteen months longer than, and not more than eighteen months shorter
than, the remaining term to stated maturity of the related Deleted Mortgage
Loan; (iv) (A) has a Loan-to-Value Ratio as of the date of such substitution of
not greater than 80%, provided, however, that if the related Deleted Mortgage
Loan has a Loan-to-Value Ratio of greater than 80%, then the Loan-to-Value Ratio
of such substitute Mortgage Loan may be greater than 80% but shall not be
greater than the Loan-to-Value Ratio of the related Deleted Mortgage Loan and
(B) the addition of such substitute Mortgage Loan does not increase the weighted
average Loan-to-Value Ratio of the related Mortgage Pool by more than 5%; (v)
will comply with all of the representations and warranties relating to Mortgage
Loans set forth herein, as of the date as of which such substitution occurs;
(vi) is not a Cooperative Loan unless the related Deleted Mortgage Loan was a
Cooperative Loan; (vii) if applicable, has the same index as and a margin not
less than that of the related Deleted Mortgage Loan; (viii) has not been
delinquent for a period of more than 30 days more than once in the twelve months
immediately preceding such date of substitution; (ix) is covered by a Primary
Mortgage Insurance Policy if the related Deleted Mortgage Loan is so covered,
and the Loan-to-Value Ratio of such Mortgage Loan is greater than 80%; (x) has a
Credit Score not greater than 20 points lower than the Credit Score of the
related Deleted Mortgage Loan, provided, however, that if the Deleted Mortgage
Loan does not have a Credit Score, then such substitute Mortgage Loan shall have
a Credit Score equal to or greater than 700; (xi) has its initial adjustment
date after the related Reset Date; and (xii) has a gross margin no less than the
related Deleted Mortgage Loan. In the event that either one mortgage loan is
substituted for more than one Deleted Mortgage Loan or more than one mortgage
loan is substituted for one or more Deleted Mortgage Loans, then (a) the
Scheduled Principal Balance referred to in clause (i) above shall be determined
such that the aggregate Scheduled Principal Balance of all such substitute
Mortgage Loans shall not exceed the aggregate Scheduled Principal Balance of all
Deleted Mortgage Loans and (b) each of (1) the rate referred to in clause (ii)
above, (2) the remaining term to stated maturity referred to in clause (iii)
above, (3) the Loan-to-Value Ratio referred to in clause (iv) above and (4) the
Credit Score referred to in clause (x) above shall be determined on a weighted
average basis, provided that the final scheduled maturity date of any Qualifying
Substitute Mortgage Loan shall not exceed the Final Scheduled Distribution Date
of any Class of Certificates. Whenever a Qualifying Substitute Mortgage Loan is
substituted for a Deleted Mortgage Loan pursuant to this Agreement, the party
effecting such substitution shall certify such qualification in writing to the
Trustee and the Master Servicer.

      Rating Agency: Each of S&P or Moody's.

      Realized Loss: (a) 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, plus (ii) interest at the applicable Net Mortgage Rate from
the date as to which interest was last paid up to the last day of the month of
such liquidation, minus (iii) Liquidation Proceeds received, net of amounts that
are reimbursable to the Master Servicer or the applicable Servicer with respect
to

                                       40
<PAGE>

such Mortgage Loan (other than Advances of principal and interest) including
expenses of liquidation or (b) with respect to each Mortgage Loan that has
become the subject of a Deficient Valuation, the difference between the unpaid
principal balance of such Mortgage Loan immediately prior to such Deficient
Valuation and the unpaid principal balance of such Mortgage Loan as reduced by
the Deficient Valuation. In determining whether a Realized Loss on a Liquidated
Mortgage Loan is a Realized Loss of interest or principal, Liquidation Proceeds
shall be allocated, first, to payment of expenses related to such Liquidated
Mortgage Loan (including payment of any Retained Interest), then to accrued
unpaid interest and finally to reduce the principal balance of the Mortgage
Loan.

      Recognition Agreement: With respect to any Cooperative Loan, an agreement
between the related Cooperative Corporation and the originator of such Mortgage
Loan to establish the rights of such originator in the related Cooperative
Property.

      Record Date: With respect to any Distribution Date and each Class of
Certificates (other than the Class 6-A1, Class 6-A2, Class 6-A3, Class B1-II,
Class B2-II, Class B3-II and Class B4-II Certificates), the close of business on
the last Business Day of the month immediately preceding the month in which such
Distribution Date occurs. The Record Date for each Distribution Date for the
Class 6-A1, Class 6-A2, Class 6-A3, Class B1-II, Class B2-II, Class B3-II and
Class B4-II Certificates will be the close of business on the Business Day
immediately preceding such Distribution Date.

      Redemption Certificate: None.

      Reference Banks: As defined in Section 4.05(c).

      Regulation S: Regulation S promulgated under the 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(c).

      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 Servicemembers Civil Relief Act or any similar state law,
any amount by which interest collectible on such Mortgage Loan for the Due Date
in the related Due 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 of REMIC I-1, REMIC I-2, REMIC I-3, REMIC I-4, REMIC II-1 and
REMIC II-2, as described in the Preliminary Statement hereto.

      REMIC I-1: REMIC I-1 as described in the Preliminary Statement hereto.

      REMIC I-1 Interest: Any one of the classes of REMIC I-1 Interests
described in the Preliminary Statement hereto.

                                       41
<PAGE>

      REMIC I-1 Regular Interest: Any of the REMIC I-1 Interests other than the
Class LTI1-R Interest.

      REMIC I-2: REMIC I-2 as described in the Preliminary Statement hereto.

      REMIC I-2 Interest: Any one of the classes of REMIC I-2 Interests
described in the Preliminary Statement hereto.

      REMIC I-2 Regular Interest: Any of the REMIC I-2 Interests other than the
Class LTI2-R Interest.

      REMIC I-3: REMIC I-3 as described in the Preliminary Statement hereto.

      REMIC I-3 Interest: Any one of the classes of REMIC I-3 Interests
described in the Preliminary Statement hereto.

      REMIC I-3 Regular Interest: Any of the REMIC I-3 Interests other than the
Class LTI3-R Interest.

      REMIC I-3 Subordinated Balance Ratio: As of any Distribution Date, the
ratio among the uncertificated Principal Balances of each of the REMIC I-3
Regular Interests ending with the designation "A" that is equal to the ratio
among, with respect to each such REMIC I-3 Regular Interest, the excess of (x)
the aggregate Scheduled Principal Balance of the Mortgage Loans in the related
Mortgage Pool over (y) the aggregate Class Principal Amounts of the Senior
Certificates of the Certificate Group related to such Mortgage Pool (after
giving effect to distributions on such Distribution Date).

      REMIC I-4: REMIC I-4 as described in the Preliminary Statement hereto.

      REMIC I-4 Regular Interest: Any of (i) the Class 1-A1, Class 1-A2, Class
2-A, Class 4-A and Class 5-A Certificates, (ii) the uncertificated REMIC regular
interests represented by the rights associated with the Class 3-A1, Class 3-A2,
Class B1-I, Class B2-I, Class B3-I, Class B4-I, Class B5-I, Class B6-I and Class
B7-I Certificates other than rights to receive payments in respect of Basis Risk
Shortfalls and Unpaid Basis Risk Shortfalls and (iii) the rights associated with
the Class 3-AX and Class 3-PAX Certificates as determined without regard to the
obligation to make payments in respect of Basis Risk Shortfalls and Unpaid Basis
Risk Shortfalls.

      REMIC I-4 Residual Interest: The sole class of residual interest in REMIC
I-4, representing the rights to receive all distributions on the Class R
Certificate other than distributions in respect of the Class LTI1-R Interest,
Class LTI2-R Interest, Class LTI3-R Interest, Class LTII1-R Interest and the
REMIC II-2 Residual Interest.

      REMIC II-1: II-1 as described in the Preliminary Statement hereto.

      REMIC II-1 Interest: Any one of the classes of REMIC II-1 Interests
described in the Preliminary Statement hereto.

                                       42
<PAGE>

      REMIC II-1 Regular Interest: Any of the REMIC II-1 Interests other than
the Class LTII1-R Interest.

      REMIC II-2: REMIC II-2 as described in the Preliminary Statement hereto.

      REMIC II-2 Regular Interest: Any of (i) the Class 6-A1, Class 6-A2, Class
6-A3, Class 6-AX1, Class 6-AX2, Class B5-II, Class B6-II, Class B7-II and Class
B8-II Certificates, (ii) the uncertificated REMIC regular interests represented
by the rights associated with the Class B1-II, Class B2-II, Class B3-II and
Class B4-II Certificates other than rights to receive payments in respect of
Subordinate Floating Rate Certificate Shortfalls and Unpaid Subordinate Floating
Rate Certificate Shortfalls and (iii) the REMIC BX-II Components.

      REMIC II-2 Residual Interest: The sole class of residual interest in REMIC
I-4 which shall not have a principal amount or interest rate and which shall be
entitled to any assets remaining in REMIC II-2 after retirement of the REMIC
II-2 Regular Interests.

      REMIC BX-II Components: Any of the REMIC B1X-II Component, REMIC B2X-II
Component, REMIC B3X-II Component and REMIC B4X-II Component.

      REMIC B1X-II Component: A regular interest in REMIC II-2 entitled to a
specified portion of the interest on the Class LTII1-B1-II Interest, such
portion being equal to the interest accrued on the Class LTII1-B1-II Interest in
excess of interest accrued at a rate equal to the Certificate Interest Rate for
the Class B1-II Certificates for such Distribution Date.

      REMIC B2X-II Component: A regular interest in REMIC II-2 entitled to a
specified portion of the interest on the Class LTII1-B2-II Interest, such
portion being equal to the interest accrued on the Class LTII1-B2-II Interest in
excess of interest accrued at a rate equal to the Certificate Interest Rate for
the Class B2-II Certificates for such Distribution Date.

      REMIC B3X-II Component: A regular interest in REMIC II-2 entitled to a
specified portion of the interest on the Class LTII1-B3-II Interest, such
portion being equal to the interest accrued on the Class LTII1-B3-II Interest in
excess of interest accrued at a rate equal to the Certificate Interest Rate for
the Class B3-II Certificates for such Distribution Date.

      REMIC B4X-II Component: A regular interest in REMIC II-2 entitled to a
specified portion of the interest on the Class LTII1-B4-II Interest, such
portion being equal to the interest accrued on the Class LTII1-B4-II Interest in
excess of interest accrued at a rate equal to the Certificate Interest Rate for
the Class B4-II Certificates for such Distribution Date.

      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.

      Remittance Date: The day in each month on which each Servicer is required
to remit payments to the account maintained by the Master Servicer, as specified
in the applicable

                                       43
<PAGE>

Servicing Agreement, which is the 18th day of each month (or if such 18th day is
not a Business Day, the next succeeding Business Day).

      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.

      Repurchase Price: As defined in Section 7.01.

      Reserve Interest Rate: As defined in Section 4.05(a)(ii).

      Reset Date: With respect to Pool 3, November 2009.

      Residual Certificate: Any Class R Certificate.

      Responsible Officer: When used with respect to the Trustee, any officer
within its corporate trust department having direct 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 B5-I, Class B6-I, Class B7-I, Class
B6-II, Class B7-II or Class B8-II Certificate but excluding any Regulation S
Global Security.

      Restricted Global Security: The meaning specified in Section 3.01(c).

      Retained Interest: Interest in respect of each Employee Mortgage Loan,
retained in each case by the Retained Interest Holder at the Retained Interest
Rate.

      Retained Interest Holder: Lehman Brothers Holdings or any successor in
interest by assignment or otherwise.

      Retained Interest Rate: For each Due Period, 0.00% per annum; provided,
however, if the Mortgagor of the Employee Mortgage Loan ceases to be an employee
of Lehman Brothers Inc. or its Affiliates, 0.25% per annum.

      Rounding Account: Not applicable.

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

      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. In the case of any bi-weekly payment Mortgage Loan, all payments due
on such Mortgage Loan during any Due Period shall be deemed collectively to
constitute the Scheduled Payment due on such Mortgage Loan in such Due Period.

                                       44
<PAGE>

      Scheduled Principal Amount: Not applicable.

      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 Due Period, whether or not received from the Mortgagor or advanced
by the applicable Servicer or the Master Servicer, and all amounts allocable to
unscheduled principal payments (including Principal Prepayments, Net Liquidation
Proceeds, Insurance Proceeds and condemnation proceeds, in each case to the
extent identified and applied prior to or during the applicable 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 as of the Cut-off Date, as
specified in the Mortgage Loan Schedule or the Participation Schedule, as the
case may be.

      Securities Administrator: Wells Fargo Bank, National Association, not in
its individual capacity but solely as Securities Administrator, or any successor
in interest, or if any successor Securities Administrator shall be appointed as
herein provided, then such successor Securities Administrator.

      Securities Administrator Fee: As to any Distribution Date and each
Mortgage Loan, an amount equal to the product of the Securities Administrator
Fee Rate and the Scheduled Principal Balance of such Mortgage Loan as of the
first day of the related Due Period.

      Securities Administrator Fee Rate: 0.0050% per annum.

      Security Agreement: With respect to any Cooperative Loan, the agreement
between the owner of the related Cooperative Shares and the originator of the
related Mortgage Note that defines the terms of the security interest in such
Cooperative Shares and the related Proprietary Lease.

      Seller: Lehman Brothers Holdings or any successor in interest.

      Senior Certificate: Any Class 1-A1, Class 1-A2, Class 2-A, Class 3-A1,
Class 3-A2, Class 3-AX, Class 3-PAX, Class 4-A, Class 5-A, Class 6-A1, Class
6-A2, Class 6-A3, Class 6-AX1, Class 6-AX2 or Class R Certificate.

      Senior Enhancement Percentage: For each Mortgage Group for any
Distribution Date the percentage equivalent of a fraction, the numerator of
which is the related Group Subordinate Amount or Group Subordinate Amounts and
the denominator of which is the related Pool Balance or Pool Balances of such
Mortgage Group for the immediately preceding Distribution Date.

      Senior Percentage: With respect to each Mortgage Pool and any Distribution
Date, the percentage equivalent of the fraction, the numerator of which is the
aggregate of the Certificate Principal Amounts of the Class 1-A1, Class 1-A2 and
Class R Certificates, in the case of Pool 1,

                                       45
<PAGE>

the Class 2-A Certificates, in the case of Pool 2, the Class 3-A1 and Class 3-A2
Certificates, in the case of Pool 3, the Class 4-A Certificates, in the case of
Pool 4, the Class 5-A Certificates, in the case of Pool 5 and the Class 6-A1,
Class 6-A2 and Class 6-A3 Certificates, in the case of Pool 6, in each case
immediately prior to such Distribution Date and the denominator of which is the
related Pool Balance for the immediately preceding Distribution Date.

      Senior Prepayment Percentage: With respect to each of Pools 1 through 5
for any Distribution Date occurring during the seven years beginning on the
first Distribution Date, 100%, except as described herein below, and with
respect to Pool 6 for any Distribution Date occurring during the ten years
beginning on the first Distribution Date, 100%, except as described herein
below. With respect to each of Mortgage Pools 1 through 5 for any Distribution
Date occurring on or after the seventh anniversary of the first Distribution
Date and the Senior Prepayment Percentage for mortgage Pool 6 for any
Distribution Date occurring on or after the tenth anniversary of the first
Distribution Date, the related Senior Percentage plus the following percentage
of the related Subordinate Percentage for such Distribution Date: for any
Distribution Date in the first year thereafter, 70%; for any Distribution Date
in the second year thereafter, 60%; for any Distribution Date in the third year
thereafter, 40%; for any Distribution Date in the fourth year thereafter, 20%;
and for any subsequent Distribution Date, 0%; provided, however, (i) if on any
of the foregoing Distribution Dates the Senior Enhancement Percentage for
Mortgage Group I or Mortgage Group II, as applicable, is less than the related
Initial Senior Enhancement Percentage, the Senior Prepayment Percentage for each
Mortgage Pool in Mortgage Group I or Mortgage Group II, as applicable, on such
Distribution Date shall once again equal 100%, (ii) unless the condition
described in clause (i) has occurred, if on any Distribution Date before the
Distribution Date in March 2008, prior to giving effect to any distributions on
such Distribution Date, the Senior Enhancement Percentage for Mortgage Group I
or Mortgage Group II, as applicable, for such Distribution Date is greater than
or equal to twice the related Initial Senior Enhancement Percentage, then the
Senior Prepayment Percentage for each Mortgage Pool in Mortgage Group I or
Mortgage Group II, as applicable, for such Distribution Date will equal the
related Senior Percentage plus 50% of the related Subordinate Percentage for
such Mortgage Pool and (iii) unless the condition described in clause (i) has
occurred, if on any Distribution Date on or after the Distribution Date in March
2008, prior to giving effect to any distributions on such Distribution Date, the
Senior Enhancement Percentage for Mortgage Group I or Mortgage Group II, as
applicable, for such Distribution Date is greater than or equal to twice the
related Initial Senior Enhancement Percentage, then the Senior Prepayment
Percentage for each Mortgage Pool in Mortgage Group I or Mortgage Group II, as
applicable, on such Distribution Date will equal the related Senior Percentage.

      Notwithstanding the foregoing, no decrease in the Senior Prepayment
Percentage for any Mortgage Pool in Mortgage Group I or Mortgage Group II, as
applicable, below the respective levels in effect for the most recent prior
period set forth in the paragraph above shall be effective on any Distribution
Date if, as of the first Distribution Date as to which any such decrease
applies, (i) the average outstanding principal balance on such Distribution Date
and for the preceding five Distribution Dates of all Mortgage Loans in the
related Mortgage Pool that were delinquent 60 days or more (including for this
purpose any Mortgage Loans in foreclosure and the Scheduled Payments that would
have been due on Mortgage Loans with respect to which the related Mortgaged
Property has been acquired by the Trust Fund if the related Mortgage Loan had
remained in existence) is greater than or equal to 50% of the applicable Group
Subordinate

                                       46
<PAGE>

Amount immediately prior to such Distribution Date or (ii) cumulative Realized
Losses with respect to the Mortgage Loans in the related Mortgage Pool exceed
(a) with respect to the Distribution Date prior to the third anniversary of the
first Distribution Date, 20% of the related Original Group Subordinate Amount,
(b) with respect to the Distribution Date on or after the third anniversary and
prior to the sixth anniversary of the first Distribution Date, 30% of the
related Original Group Subordinate Amount, (c) with respect to the Distribution
Date on or after the sixth anniversary and prior to the seventh anniversary of
the first Distribution Date, 35% of the related Original Group Subordinate
Amount, (d) with respect to the Distribution Date on or after the seventh
anniversary and prior to the eighth anniversary of the first Distribution Date,
40% of the related Original Group Subordinate Amount, (e) with respect to the
Distribution Date on or after the eighth anniversary and prior to the ninth
anniversary of the first Distribution Date, 45% of the related Original Group
Subordinate Amount, and (f) with respect to the Distribution Date on or after
the ninth anniversary of the first Distribution Date or thereafter, 50% of the
related Original Group Subordinate Amount. After the Class Principal Amount of
each Class of Senior Certificates in any Certificate Group has been reduced to
zero, the Senior Prepayment Percentage for the related Mortgage Pool shall be
0%.

      Senior Principal Distribution Amount: For each Certificate Group and any
Distribution Date, the sum of the following amounts:

            (i) the product of (a) the related Senior Percentage for such date
      and (b) the principal portion of each Scheduled Payment (without giving
      effect to any Debt Service Reduction occurring prior to the Bankruptcy
      Coverage Termination Date), on each Mortgage Loan in the related Mortgage
      Pool due during the related Due Period;

            (ii) the product of (a) the related Senior Prepayment Percentage for
      such date and (b) each of the following amounts: (1) each Principal
      Prepayment on the Mortgage Loans in the related Mortgage Pool collected
      during the related Prepayment Period, (2) each other unscheduled
      collection, including any Subsequent Recovery, Insurance Proceeds and Net
      Liquidation Proceeds (other than with respect to any Mortgage Loan in the
      related Mortgage Pool that was finally liquidated during the related
      Prepayment Period) representing or allocable to recoveries of principal in
      the related Mortgage Pool received during the related Prepayment Period,
      and (3) the principal portion of all proceeds of the purchase of any
      Mortgage Loan in the related Mortgage Pool (or, in the case of a permitted
      substitution, amounts representing a principal adjustment) actually
      received by the Securities Administrator with respect to the related
      Prepayment Period;

            (iii) with respect to unscheduled recoveries allocable to principal
      of any Mortgage Loan in the related Mortgage Pool that was finally
      liquidated during the related Prepayment Period, the lesser of (a) the
      related net Liquidation Proceeds allocable to principal and (b) the
      product of the related Senior Prepayment Percentage for such date and the
      Scheduled Principal Balance of such related Mortgage Loan at the time of
      liquidation; and

            (iv) any amounts described in clauses (i) through (iii) for any
      previous Distribution Date that remain unpaid.

                                       47
<PAGE>

If on any Distribution Date the Class Principal Amount of each Class of Senior
Certificates in any Certificate Group has been reduced to zero, the Senior
Principal Distribution Amount for such Certificate Group for such date
(following such reduction) and each subsequent Distribution Date shall be zero.

      Servicer: Any Servicer that has entered into any of the Servicing
Agreements attached as Exhibit E hereto, or any successor in interest.
Initially, the Servicers are Aurora, Colonial Savings, F.A., Countrywide Home
Loans Servicing LP, IndyMac Bank, F.S.B., Sierra Pacific Mortgage Company, Inc.,
Wachovia mortgage Corporation, Washington Mutual Bank, FA and Wells Fargo Bank,
N.A.

      Servicing Advances: Expenditures incurred by a Servicer in connection with
the liquidation or foreclosure of a Mortgage Loan which are eligible for
reimbursement under the applicable Servicing Agreement.

      Servicing Agreement: Each Servicing Agreement between a Servicer and the
Seller, dated as of February 1, 2005, attached hereto in Exhibit E, and any
other servicing agreement entered into between a successor servicer and the
Seller or the Trustee pursuant to the terms hereof.

      Servicing Fee: With respect to each Servicer, the Servicing Fee specified
in the applicable Servicing Agreement and set forth on the Mortgage Loan
Schedule.

      Servicing Fee Rate: With respect to a Servicer, the rate specified in the
applicable Servicing Agreement.

      Servicing Officer: Any officer of the Master Servicer involved in or
responsible for the administration and servicing or master servicing of the
Mortgage Loans whose name appears on a list of servicing officers furnished by
the Master Servicer to the Trustee, as such list may from time to time be
amended.

      Similar Law: As defined in Section 3.03(d).

      Special Hazard Loss: With respect to the Mortgage Loans, (x) any Realized
Loss arising out of any direct physical loss or damage to a Mortgaged Property
which is caused by or results from any cause, exclusive of any loss covered by a
hazard policy or a flood insurance policy required to be maintained in respect
of such Mortgaged Property and any loss caused by or resulting from (i) normal
wear and tear, (ii) conversion or other dishonest act on the part of the
Trustee, the Master Servicer, any Servicer or any of their agents or employees,
or (iii) errors in design, faulty workmanship or faulty materials, unless the
collapse of the property or a part thereof ensues, or (y) any Realized Loss
arising from or related to the presence or suspected presence of hazardous
wastes, or hazardous substances on a Mortgaged Property unless such loss is
covered by a hazard policy or flood insurance policy required to be maintained
in respect of such Mortgaged Property, in any case, as reported by any Servicer
to the Master Servicer.

      Special Hazard Loss Limit: As of the Cut-off Date, $7,970,411 for Pools 1
through 5 and $2,925,000 for Pool 6, which amounts shall be reduced from time to
time to an amount equal on any Distribution Date to the lesser of (a) the
greatest of (i) 1% of the aggregate of the Scheduled

                                       48
<PAGE>

Principal Balances of the related Mortgage Loans; (ii) twice the Scheduled
Principal Balance of the related Mortgage Loan having the highest Scheduled
Principal Balance, and (iii) the aggregate Scheduled Principal Balances of the
related Mortgage Loans secured by Mortgaged Properties located in the single
California postal zip code area having the highest aggregate Scheduled Principal
Balance of Mortgage Loans of any such postal zip code area and (b) the
applicable Special Hazard Loss Limit as of the Closing Date less the amount, if
any, of Special Hazard Losses incurred with respect to the related Mortgage
Loans since the Closing Date.

      Specified Rating: Not applicable.

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

      Subordinate Certificate: Any Class B Certificate.

      Subordinate Certificate Writedown Amount: As to any Distribution Date, the
amount by which (x) (i) the sum of the Class Principal Amounts of all the
Certificates related to Pools 1 through 5 (after giving effect to the
distribution of principal and the allocation of Realized Losses in reduction of
the Certificate Principal Amounts of the Certificates related to Pools 1 through
5 on such Distribution Date) exceeds (ii) the aggregate Scheduled Principal
Balance of the Mortgage Loans in Pool 1, Pool 2, Pool 3, Pool 4 and Pool 5 for
such Distribution Date or (y) (i) the sum of the Class Principal Amounts of all
the Certificates related to Pool 6 (after giving effect to the distribution of
principal and the allocation of Realized Losses in reduction of the Certificate
Principal Amounts of the Certificates related to Pool 6 on such Distribution
Date) exceeds (ii) the aggregate Scheduled Principal Balance of the Mortgage
Loans in Pool 6 for such Distribution Date.

      Subordinate Class Percentage: With respect to any Distribution Date and
any Class of Subordinate Certificates, the percentage obtained by dividing the
Class Principal Amount of such Class immediately prior to such Distribution Date
by the aggregate Certificate Principal Amount of all Subordinate Certificates
related to the same Mortgage Group immediately prior to such Distribution Date.

      Subordinate Component Percentage: Not applicable.

      Subordinate Floating Rate Certificate Shortfall: With respect to each
Distribution Date and any Class of Subordinate LIBOR Certificates, the amount
equal to the excess of the amount of Accrued Certificate Interest calculated
under clause (i) of the definition of Certificate Interest Rate for such Class
exceeds the amount of Accrued Certificate Interest as calculated based on the
LIBOR Available Funds Cap.

      Subordinate LIBOR Certificate: Any of the Class B1-II, Class B2-II, Class
B3-II or Class B4-II Certificates.

      Subordinate Percentage: With respect to each Mortgage Pool and any
Distribution Date, the difference between 100% and the related Senior Percentage
for such Distribution Date.

                                       49
<PAGE>

      Subordinate Prepayment Percentage: With respect to each Mortgage Pool and
any Distribution Date, the difference between 100% and the related Senior
Prepayment Percentage for such Distribution Date.

      Subordinate Principal Distribution Amount: For each Mortgage Pool and any
Distribution Date, the sum of the following:

            (i) the product of (a) the related Subordinate Percentage for such
        date and (b) the principal portion of each Scheduled Payment (without
        giving effect to any Debt Service Reduction occurring prior to the
        applicable Bankruptcy Coverage Termination Date) on each Mortgage Loan
        in the related Mortgage Pool due during the related Due Period;

            (ii) the product of (a) the related Subordinate Prepayment
        Percentage for such date and (b) each of the following amounts: (1) each
        Principal Prepayment on the Mortgage Loans in the related Mortgage Pool
        collected during the related Prepayment Period, (2) each other
        unscheduled collection, including Subsequent Recoveries, Insurance
        Proceeds and Net Liquidation Proceeds (other than with respect to any
        Mortgage Loan in the related Mortgage Pool that was finally liquidated
        during the related Prepayment Period) representing or allocable to
        recoveries of principal in the related Mortgage Pool received during the
        related Prepayment Period, and (3) the principal portion of all proceeds
        of the purchase of any Mortgage Loan in the related Mortgage Pool (or,
        in the case of a permitted substitution, amounts representing a
        principal adjustment) actually received by the Securities Administrator
        with respect to the related Prepayment Period;

            (iii) with respect to unscheduled recoveries allocable to principal
        of any Mortgage Loan in the related Mortgage Pool that was finally
        liquidated during the related Prepayment Period, the related net
        Liquidation Proceeds allocable to principal less any related amount paid
        pursuant to subsection (iii) of the definition of Senior Principal
        Distribution Amount for the related Certificate Group; and

            (iv) any amounts described in clauses (i) through (iii) for any
        previous Distribution Date that remain unpaid.

      Subsequent Recovery: The amount, if any, recovered by the related Servicer
or the Master Servicer with respect to a Liquidated Mortgage Loan with respect
to which a Realized Loss has been incurred after liquidation and disposition of
such Mortgage Loan.

      Surety: Not applicable.

      Surety Bond: Not applicable.

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

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

                                       50
<PAGE>

      Transfer Agreement: As defined in the Mortgage Loan Sale Agreement.

      Transferor: Each seller of Mortgage Loans to Lehman Brothers Holdings
pursuant to a Transfer Agreement.

      Trust Fund: The corpus of the trust created pursuant to this Agreement,
consisting of the Mortgage Loans (other than any Retained Interest), the
assignment of the Depositor's rights under the Mortgage Loan Sale Agreement and
the Participation Agreement, the Participations, the Additional Collateral, such
amounts as shall from time to time be held in the Collection Account, the
Certificate Account, any Escrow Account, the Insurance Policies, any REO
Property and the other items referred to in, and conveyed to the Trustee under,
Section 2.01(a).

      Trust Rate: Not applicable.

      Trust REMIC: Any of REMIC I-1, REMIC I-2, REMIC I-3, REMIC I-4, REMIC II-1
or REMIC II-2.

      Trustee: HSBC Bank USA, National Association, a national banking
association, not in its individual capacity, but solely in its capacity as
trustee for the benefit of the Certificateholders under this Agreement, and any
successor thereto, and any corporation or national banking association resulting
from or surviving any consolidation or merger to which it or its successors may
be a party and any successor trustee as may from time to time be serving as
successor trustee hereunder.

      Trustee Fee: Not applicable.

      Trustee Fee Rate: Not applicable.

      Undercollateralization Distribution: As defined in Section 5.02(h)(ii)(A).

      Undercollateralized Group: With respect to any Distribution Date, the
Senior Certificates of any Certificate Group (other than the Group 6
Certificates) as to which the aggregate Certificate Principal Amount thereof,
after giving effect to distributions pursuant to Sections 5.02(a) and (b) on
such date, is greater than the Pool Balance of the related Mortgage Pool for
such Distribution Date.

      Underlying Subordinate Rate: For Mortgage Pool 1 for each Distribution
Date, will be the Pool 1 Net WAC; for Mortgage Pool 2 for each Distribution
Date, will be the Pool 2 Net WAC; for Mortgage Pool 3 for each Distribution
Date, will be (A) for each Distribution Date on or prior to the Distribution
Date in November 2009, the lesser of (x) 5.12% and (y) the Pool 3 Adjusted Net
WAC and (B) for each Distribution Date after the Distribution Date in November
2009, the Pool 3 Net WAC; for Mortgage Pool 4 for each Distribution Date, will
be the Pool 4 Net WAC; and for Mortgage Pool 5 for each Distribution Date, will
be the Pool 5 Net WAC.

      Underwriter's Exemption: Prohibited Transaction Exemption 91-14, 56 Fed.
Reg. 7413 (1991), as amended (or any successor thereto), or any substantially
similar administrative exemption granted by the U.S. Department of Labor.

                                       51
<PAGE>

      Unpaid Basis Risk Shortfall: With respect to any Distribution Date and any
of the Class 3-A1, Class 3-A2, Class B1-I, Class B2-I, Class B3-I, Class B4-I,
Class B5-I, Class B6-I and Class B7-I Certificates, the sum of all Basis Risk
Shortfalls for such Class for prior Distribution Dates in respect of which no
payment of amounts that would otherwise have been distributed to the Class 3-AX
or Class 3-PAX Certificates has been made.

      Unpaid Subordinate Floating Rate Certificate Shortfall: With respect to
any Distribution Date, for any Class of Subordinate LIBOR Certificates the total
of all Subordinate Floating Rate Certificate Shortfalls for such Class remaining
unpaid from all previous Distribution Dates, together with interest thereon at
the applicable Certificate Interest Rate, computed without regard to the LIBOR
Available Funds Cap.

      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 until the Class
Notional Amount of each Class of Notional Certificates has been reduced to zero,
92% of all Voting Interests shall be allocated to the Certificates other than
the Notional Certificates and the Class P-1, Class P-II and Class P-III
Certificates, 5% of all Voting Interests shall be allocated to the Notional
Certificates, 1% shall be allocated to the Class P-I Certificates, 1% shall be
allocated to the Class P-II Certificates and 1% shall be allocated to the Class
P-III Certificates. After the Class Notional Amounts of all Classes of Notional
Certificates have been reduced to zero, 97% of all Voting Interests shall be
allocated to the remaining Classes of Certificates other than the Class P-I,
Class P-II and Class P-III Certificates. Voting Interests allocated to the
Notional Certificates shall be allocated among the Classes of such Certificates
(and among the Certificates of each such Class) in proportion to their Class
Notional Amounts (or Notional Amounts). Voting Interests shall be allocated
among the Class P-I, Class P-II and Class P-III Certificates in proportion to
their Percentage Interest. Voting Interests shall be allocated among the other
Classes of Certificates (and among the Certificates of each such Class) in
proportion to their Class Principal Amounts (or Certificate Principal Amounts).

    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 distributions to be made
to the Certificateholders as supplied to the Securities Administrator by the
Master Servicer. The Securities Administrator shall not be required to
recompute, verify or recalculate the information supplied to it by the Master
Servicer.

                                   ARTICLE II

                              DECLARATION OF TRUST;
                            ISSUANCE OF CERTIFICATES

    Section 2.01. Creation and Declaration of Trust Fund; Conveyance of
Mortgage Loans.

                                       52
<PAGE>

      (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 (including the Participations). Such conveyance includes,
without limitation, the right to all distributions 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, any Escrow Account
established pursuant to Section 9.06 hereof and all amounts from time to time
credited to and the proceeds of any such Escrow Account, any REO Property and
the proceeds thereof, the Depositor's rights under any Insurance Policies
related to the Mortgage Loans, and 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 (or a Custodian on its behalf) 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 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
applicable Servicing Agreement to the extent assigned under the Mortgage Loan
Sale Agreement. The Trustee hereby accepts such assignment, and shall be
entitled to exercise all 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 either (i) a "High-Cost Home Loan" as defined in the New Jersey Home
Ownership Act effective November 27, 2003 or (ii) a "High-Cost Home Loan" as
defined in the New Mexico Home Loan Protection Act effective January 1, 2004.

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

      In addition, with respect to any Pledged Asset Mortgage Loan, the
Depositor does hereby transfer, assign, set-over and otherwise convey to the
Trustee without recourse (except as provided herein) (i) its rights as assignee
under any security agreements, pledge agreements or

                                       53
<PAGE>

guarantees relating to the Additional Collateral supporting any Pledged Asset
Mortgage Loan, (ii) its security interest in and to any Additional Collateral,
(iii) its right to receive payments in respect of any Pledged Asset Mortgage
Loan pursuant to the Additional Collateral Servicing Agreement, and (iv) its
rights as beneficiary under the surety bond in respect of any Pledged Asset
Mortgage Loan. Notwithstanding anything to the contrary in this Agreement, the
Trust Fund shall not obtain title to or beneficial ownership of any Additional
Collateral as a result of or in lieu of the disposition thereof or otherwise.

      (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 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 (other than the Participations):

            (i) with respect to each Mortgage Loan, the original Mortgage Note
      endorsed without recourse in proper form to the order of the Trustee, or
      in blank (in each case, with all necessary intervening endorsements as
      applicable);

            (ii) the original of any guarantee, security agreement or pledge
      agreement relating to any Additional Collateral and executed in connection
      with the Mortgage Note, assigned to the Trustee;

            (iii) with respect to each Mortgage Loan other than a Cooperative
      Loan, the original recorded Mortgage with evidence of recording indicated
      thereon and the original recorded power of attorney, if the Mortgage was
      executed pursuant to a power of attorney, with evidence of recording
      thereon or, if such Mortgage or power of attorney has been submitted for
      recording but has not been returned from the applicable public recording
      office, has been lost or is not otherwise available, a copy of such
      Mortgage or power of attorney, as the case may be, certified to be a true
      and complete copy of the original submitted for recording. If, in
      connection with any Mortgage Loan, the Depositor cannot deliver the
      Mortgage 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 has
      been lost, the Depositor shall deliver or cause to be delivered to the
      Trustee (or its custodian), in the case of a delay due to recording, a
      true copy of such Mortgage, pending delivery of the original thereof,
      together with an Officer's Certificate of the Depositor certifying that
      the copy of such Mortgage delivered to the Trustee (or its custodian) is a
      true copy and that the original of such Mortgage has been forwarded to the
      public recording office, or, in the case of a Mortgage that has been lost,
      a copy thereof (certified as provided for under the laws of the
      appropriate jurisdiction) and a written Opinion of Counsel acceptable to
      the Trustee and the Depositor that an original recorded Mortgage is not
      required to enforce the Trustee's interest in the Mortgage Loan;

            (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

                                       54
<PAGE>

      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 its 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 other than a
      Cooperative Loan, the original Assignment of Mortgage, in form and
      substance acceptable for recording. The Mortgage shall be assigned either
      (A) in blank, without recourse or (B) to "HSBC Bank USA, National
      Association, as Trustee of the Structured Adjustable Rate Mortgage Loan
      Trust Mortgage Pass Through Certificates, Series 2005-4," without recourse
      for each Mortgage Loan;

            (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 acceptable to
      the Trustee that such original Intervening Assignment is not required to
      enforce the Trustee's interest in the Mortgage Loans;

            (vii) the original Primary Mortgage Insurance Policy or certificate,
      if private mortgage guaranty insurance is required;

            (viii) with respect to each Mortgage Loan other than a Cooperative
      Loan, the original mortgagee title insurance policy or attorney's opinion
      of title and abstract of title;

            (ix) the original of any security agreement, chattel mortgage or
      equivalent executed in connection with the Mortgage or as to any security
      agreement, chattel mortgage or their equivalent 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
      delivered to the Trustee (or its custodian) is a true copy and that the
      original of such document has been forwarded to the public recording
      office; and

            (x) with respect to any Cooperative Loan, the Cooperative Loan
      Documents.

      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.

      With respect to each Participation, the Depositor does hereby deliver to,
and deposit with, or cause to be delivered to and deposited with, the Trustee,
and/or any custodian acting on the

                                       55
<PAGE>

Trustee's behalf, a copy of the Participation Agreement and the original
Participation issued to the Trustee.

      (c)   (i)   Assignments of Mortgage with respect to each Non-MERS
      Mortgage Loan other than a Cooperative Loan shall be recorded; provided,
      however, that such Assignments need not be recorded if, in the Opinion of
      Counsel (which must be from Independent counsel) acceptable to the Trustee
      and the Rating Agencies, recording in such states is not required to
      protect the Trustee's interest in the related Non-MERS Mortgage Loans.
      Subject to the preceding sentence, as soon as practicable after the
      Closing Date (but in no event more than 3 months thereafter except to the
      extent delays are caused by the applicable recording office), the Master
      Servicer (or its Custodian), at the expense of the Depositor and with the
      cooperation of the applicable Servicer, shall cause to be properly
      recorded by such 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 a Non-MERS Mortgage Loan. With
      respect to each Cooperative Loan, the Master Servicer (or its Custodian),
      at the expense of the Depositor and with the cooperation of the applicable
      Servicer, shall cause such Servicer to take such actions as are necessary
      under applicable law in order to perfect the interest of the Trustee in
      the related Mortgaged Property.

            (ii) With respect to each MERS Mortgage Loan, the Master Servicer
      (or its applicable Custodian), at the expense of the Depositor and with
      the cooperation of the applicable Servicer, shall cause to be taken such
      actions by such Servicer 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 to the applicable Custodian on behalf of the
Trustee, under clause (b)(viii) 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 applicable 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 applicable Servicer in
trust for the benefit of the Trustee and the Certificateholders.

      Section 2.02. Acceptance of Trust Fund by Trustee: Review of Documentation
for Trust Fund.

                                       56
<PAGE>

      (a)   The Trustee or the applicable Custodian on behalf of the Trustee, by
execution and delivery hereof, acknowledges receipt of the Participations and
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
Trustee, the Depositor and the Master Servicer 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 applicable Custodian
will, on behalf of the Trustee and 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 make sure that the 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 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, shall promptly identify the
Mortgage Loan to which such Material Defect relates in the Interim Certificate
delivered to the Depositor or the Master Servicer (and to the Trustee). 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, it 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 Servicer 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

                                       57
<PAGE>

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.

      (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 annexed hereto 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 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 hold the related Mortgage Files and shall perform the applicable
review of the Mortgage Loans and deliver the respective certifications thereof
as provided in this Section 2.02 and the related Custodial Agreement.

      Section 2.03. Representations and Warranties of the Depositor.

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

            (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; neither the execution and delivery of this Agreement, nor
      the consummation of the transactions herein contemplated, nor 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

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<PAGE>

      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 Securities Administrator and the Master Servicer, 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) 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, (2) 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 (3) 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.

      (b)   The representations and warranties of each Transferor with respect
to the related Mortgage Loans in the applicable Transfer Agreement, which have
been assigned to the Trustee hereunder, were made as of the date specified in
the applicable Transfer Agreement (or underlying agreement, if such Transfer
Agreement is in the form of an assignment of a prior agreement). To the extent
that any fact, condition or event with respect to a Mortgage Loan constitutes a
breach of both (i) a representation or warranty of the applicable Transferor
under

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<PAGE>

the applicable Transfer Agreement and (ii) a representation or warranty of
Lehman Brothers Holdings under the Mortgage Loan Sale Agreement, the only right
or remedy of the Trustee or of any Certificateholder shall be the Trustee's
right to enforce the obligations of the applicable Transferor under any
applicable representation or warranty made by it. The Trustee acknowledges that
Lehman Brothers Holdings shall have no obligation or liability with respect to
any breach of a representation or warranty made by it with respect to the
Mortgage Loans if the fact, condition or event constituting such breach also
constitutes a breach of a representation or warranty made by the applicable
Transferor in the applicable Transfer Agreement, without regard to whether such
Transferor fulfills its contractual obligations in respect of such
representation or warranty. The Trustee further acknowledges that the Depositor
shall have no obligation or liability with respect to any breach of any
representation or warranty with respect to the Mortgage Loans (except as set
forth in Section 2.03(a)(vi)) under any circumstances.

      Section 2.04. Discovery of Breach.

      It is understood and agreed that the representations and warranties (i)
set forth in Section 2.03, (ii) of Lehman Brothers Holdings set forth in the
Mortgage Loan Sale Agreement and assigned to the Trustee by the Depositor
hereunder and (iii) of each Transferor, assigned by Lehman Brothers Holdings 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 either
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. Within 90 days of the discovery of a
breach of any representation or warranty given or assigned to the Trustee by the
Depositor, any Transferor, or Lehman Brothers Holdings, the Depositor, such
Transferor, or Lehman Brothers Holdings, as applicable, shall either (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. In the event
of discovery of a breach of any representation and warranty of any Transferor
assigned to the Trustee, the Trustee shall enforce its rights under the
applicable Transfer Agreement and the Mortgage Loan Sale Agreement for the
benefit of Certificateholders. As provided in the Mortgage Loan Sale Agreement,
if any Transferor substitutes for a Mortgage Loan for which there is a breach of
any representations and warranties in the related Transfer Agreement which
adversely and materially affects the value of such Mortgage Loan and such
substitute mortgage loan is not a Qualifying Substitute Mortgage Loan, under the
terms of the Mortgage Loan Sale Agreement, Lehman Brothers Holdings will, in
exchange for such substitute Mortgage Loan, (i) provide the applicable Purchase
Price for the affected Mortgage Loan or (ii) within two years of the Closing
Date, substitute such affected Mortgage Loan with a Qualifying Substitute
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, by Lehman Brothers Holdings pursuant to the
applicable Mortgage Loan Sale Agreement or by any Transferor pursuant to the
applicable Transfer Agreement, the principal

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portion of the funds received by the Master Servicer in respect of such
repurchase of a Mortgage Loan will be considered a Principal Prepayment and
shall be deposited in the Collection Account pursuant to Section 4.01. The
Trustee, upon receipt of the full amount of the Purchase Price for a Deleted
Mortgage Loan, or upon receipt of notification from the related Custodian that
it 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 to the Depositor, Lehman Brothers
Holdings or the applicable Transferor, 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 Trustee (or a Custodian),
and the Trustee shall have no further responsibility with respect to the
Mortgage File relating to such Deleted Mortgage Loan.

      (b)   With respect to each Qualifying Substitute Mortgage Loan to be
delivered to the Trustee (or a Custodian) pursuant to the terms of this Article
II in exchange for a Deleted Mortgage Loan: (i) the Depositor, the applicable
Transferor, or Lehman Brothers Holdings, as applicable, must deliver to the
Trustee (or its 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 the granting language set forth in Section 2.01(a); and (ii) the
Depositor will be deemed to have made, with respect to such Qualified 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 applicable 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 such Servicer if required pursuant to Section
2.01(c)(i), or (ii) with respect to a Qualifying Substitute Mortgage Loan that
is a MERS Mortgage Loan, cause to be taken such actions by such Servicer 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)(ii).

      (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 (at the expense of the party seeking to make the
substitution) that, under current law, such substitution will not (A) affect
adversely the status of any REMIC established hereunder as a REMIC, or of the
related "regular interests" as "regular interests" in any such REMIC, or (B)
cause any such REMIC to engage in a "prohibited transaction" or prohibited
contribution pursuant to the REMIC Provisions. The Depositor shall cause the
Mortgage Loan Schedule to be amended in accordance with the terms of this
Agreement.

      Section 2.06. Grant Clause.

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<PAGE>

      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: (i) the
rights and obligations of the parties shall be established pursuant to the terms
of this Agreement; (ii) the Depositor hereby grants to the Trustee for the
benefit of the Holders of the Certificates a first priority security interest in
all of the Depositor's right, title and interest in, to and under, whether now
owned or hereafter acquired, the Trust Fund and all proceeds of any and all
property constituting the Trust Fund to secure payment of the Certificates; and
(iii) this Agreement shall constitute a security agreement under applicable law.
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, 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.

                                  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 Notional Principal Amount, as applicable, or in
the Percentage Interests, specified herein. Each Class of Book-Entry
Certificates shall be issued in the minimum denominations in Certificate
Principal Amount (or Notional Amount) or Percentage Interest specified in the
Preliminary Statement hereto and in integral multiples of $1 or 5% (in the case
of Certificates issued in Percentage Interests) in excess thereof. Each Class of
Non-Book Entry Certificates other than the Residual Certificate shall be issued
in definitive, fully registered form in the minimum denominations in Certificate
Principal Amount (or Notional Amount) specified in the Preliminary Statement
hereto and in integral multiples of $1 in excess thereof. The Residual
Certificate shall be issued as a single Certificate and maintained in
definitive, fully registered form in a minimum denomination equal to $100. Each
of the Class P Certificates shall be maintained in definitive, fully registered
form in a minimum denomination equal to 25% of the Percentage Interest of such
Class of Certificates. The Certificates may be issued in the form of typewritten
certificates. One Certificate of each Class of Certificates other than any Class
of Residual Certificates may be issued in any denomination in excess of the
minimum denomination.

      (b)   The Certificates shall be executed by manual or facsimile signature
on behalf of the Authenticating Agent by an authorized officer of the Trustee or
the Authenticating Agent. Each Certificate shall, on original issue, be
authenticated by the Authenticating Agent upon the order of the Depositor upon
receipt by the Trustee 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

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<PAGE>

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)   The Class B5-I, Class B6-I, Class B7-I, Class B6-II, Class B7-II or
Class B8-II Certificates 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 Securities Administrator, 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 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.

      The Class B5-I, Class B6-I, Class B7-I, Class B6-II, Class B7-II or Class
B8-II Certificates 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
Securities Administrator, 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 Securities Administrator or DTC or its nominee, as the case may
be, as hereinafter provided.

      (d)   The Class B5-I, Class B6-I, Class B7-I, Class B6-II, Class B7-II or
Class B8-II Certificates sold to an "accredited investor" complying with the
transfer provision set forth in Section 3.03 under Rule 501(a)(1), (2), (3) or
(7) under the Act shall be issued initially in the form of one or more
Definitive Certificates.

      Section 3.02. Registration.

      The Securities Administrator is hereby appointed, and hereby accepts its
appointment as, the initial Certificate Registrar in respect of the Certificates
and shall maintain books for the registration and for the transfer of
Certificates (the "Certificate Register"). A registration book shall be
maintained for the Certificates 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,

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<PAGE>

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.

      Section 3.03. Transfer and Exchange of Certificates.

      (a)   A Certificate (other than Book-Entry Certificates 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 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 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 of 1933, as amended (the "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

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<PAGE>

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 under the Act,
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.

      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 the Placement Agent, an affiliate (as defined in Rule 405 under the
      Act) of the Depositor or the Placement Agent or (y) being made to a QIB by
      a transferor that has provided the Certificate Registrar 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 Act
      by a transferor who furnishes to the Certificate Registrar a letter of the
      transferee substantially in the form of Exhibit G hereto.

      (d)   No Transfer of an ERISA-Restricted Certificate that is a Class R
Certificate will be registered unless the Trustee, the Certificate Registrar and
the Depositor receive a representation as set forth in Exhibit D-1 to the effect
that such transferee is not an employee benefit plan or arrangement subject to
Title I of ERISA, a plan subject to Section 4975 of the Code or a plan subject
to any provisions under any federal, state, local, non-U.S. or other laws or
regulations that are substantively similar to the foregoing provisions of ERISA
or the Code ("Similar Law") (collectively, a "Plan"), and is not directly or
indirectly acquiring the Class R Certificate for, on behalf of, or with any
assets of any such Plan. Each Person to whom a Class R Certificate is to be
transferred shall be required or deemed to represent that it is not a Plan.

      No Transfer of an ERISA-Restricted Certificate (other than the Class R
Certificate) will be registered unless the Trustee, the Certificate Registrar
and the Depositor receive (A) a representation as set forth in Exhibit H that
the transferee is not a Plan and is not directly or indirectly acquiring the
Certificate for, on behalf of, or with any assets of any such Plan, (B) if the
Certificate has been the subject of an ERISA-Qualifying Underwriting, a
representation as set forth in Exhibit H that such transferee is an insurance
company that is acquiring the Certificate with assets contained in an "insurance
company general account," as defined in Section V(e) of Prohibited Transaction
Class Exemption ("PTCE") 95-60, and the acquisition and holding of the
Certificate are covered and exempt under Sections I and III of PTCE 95-60, or
(C) solely in the case of a Definitive Certificate, an Opinion of Counsel
satisfactory to the Trustee, the Certificate Registrar and the Depositor, and
upon which the Trustee, the Certificate Registrar and the Depositor shall be
entitled to rely, to the effect that the acquisition and holding of such

                                       65
<PAGE>
\
Certificate will not constitute or result in a nonexempt prohibited transaction
under ERISA or the Code, or a violation of Similar Law, and will not subject the
Trustee, the Certificate Registrar, the Master Servicer or the Depositor to any
obligation in addition to those expressly undertaken in this Agreement, which
Opinion of Counsel shall not be an expense of the Trustee, the Certificate
Registrar, the Master Servicer or the Depositor.

      For purposes of this Subsection 3.03(d), other than clause (C) in the
immediately preceding paragraph, the representations set forth in Exhibit D-1 or
Exhibit H, as applicable, shall be deemed to have been made to the Trustee, the
Certificate Registrar and the Depositor by the transferee's acceptance of an
ERISA- Restricted Certificate (or the acceptance by a Certificate Owner of the
beneficial interest in any Class of ERISA-Restricted Certificates). The Trustee,
the Certificate Registrar and the Depositor shall not have any obligation to
monitor transfers of Book-Entry Certificates or Restricted Global Securities
that are ERISA-Restricted Certificates or any liability for transfers of such
Certificates in violation of the transfer restrictions.

      Notwithstanding any other provision herein to the contrary, any purported
transfer of an ERISA-Restricted Certificate to or on behalf of a Plan without
the delivery to the Trustee, the Certificate Registrar and the Depositor of a
representation or an Opinion of Counsel satisfactory to the Trustee, the
Certificate Registrar and the Depositor as described above shall be void and of
no effect. The Trustee, the Certificate Registrar and the Depositor shall not
have any liability to any Person for any registration or transfer of any
ERISA-Restricted Certificate that is in fact not permitted by this Section
3.03(d) and the Trustee, the Certificate Registrar and the Depositor shall not
have any liability 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, the
Certificate Registrar and the Depositor shall be entitled, but not obligated, to
recover from any Holder of any ERISA-Restricted Certificate that was in fact a
Plan and that held such Certificate in violation of this Section 3.03(d) all
payments made on such ERISA-Restricted Certificate at and after the time it
commenced such holding. Any such payments so recovered shall be paid and
delivered to the last preceding Holder of such Certificate that is not a Plan.

      (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 Certificate.

      (f)   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, in the case of clause (ii),
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

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<PAGE>

Service Form 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").

      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 or the Certificate Registrar an affidavit in
substantially the form attached hereto as Exhibit D-1 representing and
warranting, among other things, that such transferee is neither a Disqualified
Organization, an agent or nominee acting on behalf of a Disqualified
Organization, nor 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 or the Certificate Registrar 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 Trustee and the Certificate Registrar 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 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. Neither the Trustee nor the Certificate Registrar shall 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(f), unless the
Trustee or the Certificate Registrar 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, agent or nominee thereof, or Non-permitted Foreign
Holder. The Trustee or the Certificate Registrar shall be entitled 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 or the Certificate Registrar 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(f), then upon
receipt of written notice to the Trustee or the Certificate Registrar that the
registration of transfer of such Residual Certificate was not in fact permitted
by this Section 3.03(f), 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. Neither the Trustee nor
the Certificate Registrar shall be under any liability to any Person for any
registration of transfer of a Residual Certificate that is in fact not

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permitted by this Section 3.03(f), 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(f).

      (g)   Each Holder of a Residual Certificate, by such Holder's acceptance
thereof, shall be deemed for all purposes to have consented to the provisions of
this section.

      (h)   Notwithstanding any provision to the contrary herein, so long as a
Global Security representing any of the Class B5-I, Class B6-I, Class B7-I,
Class B6-II, Class B7-II or Class B8-II Certificates 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(h).

                  (A)   Subject to clauses (B) and (C) of this Section 3.03(h),
            transfers of a Global Security representing any of the Class B5-I,
            Class B6-I, Class B7-I, Class B6-II, Class B7-II or Class B8-II
            Certificates 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
            Certificate Registrar, of (I) instructions from DTC directing the
            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 L-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 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

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<PAGE>

            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.

                  (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 DTC, exchange or cause the exchange of
            such interest for an equivalent beneficial interest in a Restricted
            Global Security. Upon receipt by the Certificate Registrar, of (I)
            instructions from DTC directing the 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 L-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 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 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 Act, as the case may be), and as may be
            from time to time adopted by the Certificate Registrar.

                  (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(h)(C).

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      Section 3.04. Cancellation of Certificates.

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

      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 or 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 Depositor 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 Securities Administrator, 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 neither the Depositor, the Securities Administrator,
the Master Servicer, the Trustee, the Certificate Registrar nor 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 the Authenticating Agent 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

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surrender of the temporary Certificates at the office or agency of the
Certificate Registrar without charge to the Holder. Upon surrender for
cancellation of any one or more temporary Certificates, the Trustee shall
execute and the Authenticating Agent shall 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.

      Section 3.08. Appointment of Paying Agent.

      The Trustee may appoint a Paying Agent (which may be the Trustee) for the
purpose of making distributions to Certificateholders hereunder. The Securities
Administrator is hereby appointed, and hereby accepts its appointment as Paying
Agent in respect of the Certificates. 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.

      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, to be delivered to The Depository Trust Company, the
initial Clearing Agency, by, or on behalf of, the Depositor. 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 Securities Administrator, the Master
      Servicer, the Paying Agent, the Certificate 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;

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<PAGE>

            (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

            (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 Certificate Registrar 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 Trustee or the Depositor is unable to locate a qualified successor, (ii)
the Depositor, at its option, advises the Trustee in writing that it elects to
terminate the book-entry system through the Clearing Agency or (iii) 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.

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      (a)   On the Closing Date, the Master Servicer shall open and shall
thereafter maintain a segregated account held in trust (the "Collection
Account"), entitled "Aurora Loan Services LLC, as Master Servicer, in trust for
the benefit of the Holders of Structured Adjustable Rate Mortgage Loan Trust
Mortgage Pass-Through Certificates, Series 2005-4." The Collection Account shall
relate solely to the Certificates issued by the Trust Fund hereunder, and funds
in such Collection Account shall not be commingled with any other monies.

      (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 30 days
and transfer all funds on deposit in such existing Collection Account into such
new Collection Account.

      (c)   The Master Servicer shall give to the Trustee and the Securities
Administrator 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. 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), not including any amounts which are to be excluded
from the Available Distribution Amount for such Distribution Date pursuant to
clauses (A) through (H) of paragraph (i) of the definition thereof (other than
any amounts due or reimbursable to the Trustee, the Custodians or the Securities
Administrator pursuant to this Agreement), shall be remitted to the Securities
Administrator for deposit into the Certificate Account by wire transfer in
immediately available funds. The Master Servicer, at its option, may choose to
make daily remittances from the Collection Account to the Securities
Administrator 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 Business Day following the Closing Date,
any amounts representing Scheduled Payments on the Mortgage Loans due after the
Cut-off Date and received by the Master Servicer on or before the Closing Date.
Thereafter, the Master Servicer shall deposit or cause to be deposited in the
Collection Account on the applicable Remittance Date 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 and late collections, on the Mortgage Loans;

            (ii) all payments on account of interest on the Mortgage Loans
      (other than payments due prior to the Cut-off Date), net of the applicable
      Servicing Fee and Master 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 any
      Subsequent Recovery, 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 any unpaid Servicing Fees
      and Master Servicing Fees with respect to

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<PAGE>

      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; provided that if the applicable Servicer is also
      the Retained Interest Holder with respect to any Mortgage Loan, payments
      on account of interest on the Mortgage Loans as to which such Servicer is
      the Retained Interest Holder may also be made net of the related Retained
      Interest with respect to each such Mortgage Loan.

            (iv) all Insurance Proceeds;

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

            (vi) all Prepayment Penalty Amounts; and

            (vii) all proceeds of any Mortgage Loan purchased by any Person.

      (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 Structured Adjustable Rate Mortgage Loan
Trust, Mortgage Pass-Through Certificates, Series 2005-4. All income and gain
realized from any such investment shall be for the benefit of the Master
Servicer, while such Collection Account is maintained by the Master Servicer,
and shall be subject to its withdrawal or order from time to time 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 or
assumption fees need not be deposited by the Master Servicer in the Collection
Account and may be retained by the Master Servicer or the applicable 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 any Servicer for Advances made by it or
      by such Servicer pursuant to Section 5.04 or the applicable Servicing
      Agreement; the Master Servicer's right to reimburse itself pursuant to
      this subclause (i) is limited to amounts received on or in respect of
      particular Mortgage Loans (including, for this purpose, Liquidation
      Proceeds and amounts representing Insurance Proceeds with respect to the

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      property subject to the related Mortgage) which represent late recoveries
      (net of the applicable Servicing Fee and the Master 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;

            (ii) to reimburse itself or any Servicer for any Advances or
      Servicing Advances made by it or by such Servicer that it or such Servicer
      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 or Servicing Advance was
      made or from Liquidation Proceeds or Insurance Proceeds with respect to
      such Mortgage Loan, it being understood, in the case of any 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 any Servicer from Liquidation Proceeds
      for Liquidation Expenses and for amounts expended by it pursuant to
      Sections 9.20 and 9.22(a) or the applicable 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 applicable Servicing Fee and the Master Servicing Fee 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) in the event it has elected not to pay itself the Master
      Servicing Fee out of any Mortgagor payment on account of interest or other
      recovery with respect to a particular Mortgage Loan prior to the deposit
      of such Mortgagor payment or recovery in the Collection Account, to pay to
      itself the Master Servicing Fee for each Distribution Date and any unpaid
      Master Servicing Fees for prior Distribution Dates, as reduced pursuant to
      Section 5.05, from any Mortgagor payment as to interest or such other
      recovery with respect to that Mortgage Loan, as is permitted by this
      Agreement;

            (v) to reimburse itself or any Servicer for expenses incurred by and
      recoverable by or reimbursable to it or such Servicer pursuant to Section
      9.04, 9.06, 9.16 or 9.22(a) or pursuant to the applicable Servicing
      Agreement (to the extent such reimbursement constitutes "unanticipated
      expenses" within the meaning of Treasury Regulation Section
      1.860G-1(b)(3)(ii)), and to reimburse itself for any expenses reimbursable
      to it pursuant to Section 10.01(c);

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<PAGE>

            (vi) to pay to the applicable Person, with respect to each Mortgage
      Loan or REO Property acquired in respect thereof that has been repurchased
      by such Person pursuant to this Agreement, all amounts received thereon
      and not distributed on the date on which the related repurchase was
      effected;

            (vii) subject to Section 5.04, to pay to itself income earned on the
      investment of funds deposited in the Collection Account;

            (viii) to make payments to the Securities Administrator on each
      Master Servicer Remittance Date for deposit into the Certificate Account
      in the amounts and in the manner provided for in Section 4.04;

            (ix) to make distributions of the Retained Interest to the Retained
      Interest Holder on each Distribution Date (other than any Retained
      Interest not deposited into the Collection Account in accordance with
      Section 4.01(d)(iii));

            (x) to make payment to itself, the Trustee and others pursuant to
      any provision of this Agreement and to reimburse the Custodian pursuant to
      the Custodial Agreement, but only to the extent that the items reimbursed
      constitute "unanticipated expenses" within the meaning of Treasury
      Regulation Section 1.860G-1(b)(3)(ii);

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

            (xii) to clear and terminate any Collection Account pursuant to
      Section 7.02;

            (xiii) to reimburse a successor Master Servicer (solely in its
      capacity as successor Master Servicer, including the Securities
      Administrator), for any fee or advance occasioned by a termination of the
      Master Servicer, and the assumption of such duties by the Securities
      Administrator or a successor Master Servicer appointed by the Securities
      Administrator 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 Securities Administrator thereto shall be prior to the
      rights of the Certificateholders; and

            (xiv) to reimburse any Servicer for such amounts as are due thereto
      under the applicable Servicing Agreement and have not been retained by or
      paid to such Servicer to the extent provided in such Servicing Agreement
      provided such amounts are Servicing Fees or "unanticipated expenses"
      within the meaning of Treasury Regulation Section 1.860G-1(b)(3)(ii).

      If provided in the related Servicing Agreement, each Servicer shall be
entitled to retain as additional servicing compensation any Prepayment Interest
Excess (to the extent not offset by Prepayment Interest Shortfalls). The
Servicers of the Participations shall be entitled to retain as additional
servicing compensation any Prepayment Penalty Amounts received with respect to
the Participations.

      In connection with withdrawals pursuant to subclauses (i), (iii), (iv) and
(vi) above, the Master Servicer's or Servicer's entitlement thereto is limited
to collections or other recoveries on

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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 from the Collection Account it maintains pursuant
to such subclause (i), (iii), (iv) and (vi).

      In the event that the Master Servicer fails on any Master Servicer
Remittance Date to remit to the Securities Administrator any amounts required to
be so remitted to the Securities Administrator pursuant to sub-clause (viii) by
such date, the Master Servicer shall pay the Securities Administrator, for the
account of the Securities Administrator, 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 Securities Administrator
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).

      Section 4.03. Reports to Certificateholders.

      (a)   On each Distribution Date, the Securities Administrator shall have
prepared (based on information provided by the Master Servicer) and shall make
available to the Trustee and each Certificateholder a written report setting
forth the following information, by Mortgage Pool and Certificate Group (on the
basis of Mortgage Loan level information obtained from the applicable Servicer
and the Master Servicer):

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

            (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, including any Accrual Amount added to the Class Principal
      Amount of any Class of Accrual Certificates;

            (iii) the amount, if any, of any distribution to the Holders of a
      Residual Certificate;

            (iv) (A) the aggregate amount of any Advances required to be made by
      or on behalf of the Master Servicer or any Servicer (or, if applicable,
      the Securities Administrator, solely in its capacity as successor 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 Aggregate Principal Balance of the Mortgage Loans and the
      Pool Balance of each Mortgage Pool for such Distribution Date, after
      giving effect to payments allocated to principal reported under clause (i)
      above;

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            (vi) the Class Principal Amount (or Class Notional 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 (and to the addition of any Accrual Amount in the case of
      any Class of Accrual Certificates), separately identifying any reduction
      of any of the foregoing Certificate Principal Amounts due to Realized
      Losses;

            (vii) any Realized Losses realized with respect to the Mortgage
      Loans (x) in the applicable Prepayment Period and (y) in the aggregate
      since the Cut-off Date, stating separately the amount of Special Hazard
      Losses, Fraud Losses and Bankruptcy Losses and the aggregate amount of
      such Realized Losses, and the remaining Special Hazard Loss Amount, Fraud
      Loss Amount and Bankruptcy Loss Amount;

            (viii) the amount of the Master Servicing Fees, Servicing Fees and
      Securities Administrator Fee paid during the Due Period to which such
      distribution relates;

            (ix) the number and aggregate Scheduled Principal Balance of
      Mortgage Loans, as reported to the Securities Administrator by the Master
      Servicer, (a) remaining outstanding, (b) delinquent one month, (c)
      delinquent two months, (d) delinquent three or more months and (e) as to
      which foreclosure proceedings have been commenced 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;

            (x) the deemed aggregate principal balance of all REO Properties 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;

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

            (xii) the aggregate outstanding Interest Shortfalls and Net
      Prepayment Interest Shortfalls, if any, for each Class of Certificates,
      after giving effect to the distribution made on such Distribution Date;

            (xiii) the Certificate Interest Rate applicable to such Distribution
      Date with respect to each Class of Certificates;

            (xiv) 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);

            (xv) the amount of payments made to each of the Class 3-A1, Class
      3-A2, Class B1-I, Class B2-I, Class B3-I, Class B4-I, Class B5-I, Class
      B6-I and Class B7-I Certificates in respect of Basis Risk Shortfalls and
      Unpaid Basis Risk Shortfalls;

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            (xvi) the amount of payments made to each of the Class B1-II, Class
      B2-II, Class B3-II and Class B4-II Certificates in respect of Subordinate
      Floating Rate Certificate Shortfalls and Unpaid Subordinate Floating Rate
      Certificate Shortfalls; and

            (xvii) the amount of payments made to each Class of Certificates
      that are treated as payments received in respect of a REMIC I-4 Regular
      Interest or REMIC II-2 Regular Interest and the amount of any payments to
      each Class of Certificates that are not treated as payments in respect of
      a REMIC I-4 Regular Interest or REMIC II-2 Regular Interest.

      In the case of information furnished pursuant to subclauses (i), (ii) and
(viii) above, the amounts shall be expressed as a dollar amount per $1,000 of
original principal amount of Certificates.

      The Securities Administrator shall make such report and additional loan
level information (and, at its option, any additional files provided by the
Master Servicer containing the same information in an alternative format)
available each month to the Trustee, Certificateholders and the Rating Agencies
via the Securities Administrator's internet website. The Trustee's internet
website shall initially be located at www.ctslink.com. Assistance in using the
website can be obtained by calling the Securities Administrator's customer
service desk at (301) 815-6600. 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. The Securities Administrator
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 Securities Administrator 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 Securities Administrator based solely on Mortgage Loan data provided to the
Securities Administrator by the Master Servicer no later than four Business Days
prior to the Distribution Date. In preparing or furnishing the Mortgage Loan
data to the Securities Administrator, the Master Servicer shall be entitled to
rely conclusively on the accuracy of the information or data regarding the
Mortgage Loans and the related REO Property that has been provided to the Master
Servicer by each Servicer, and the Master Servicer shall not be obligated to
verify, recompute, reconcile or recalculate any such information or data. The
Securities Administrator 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 or other information.

      On each Distribution Date, the Securities Administrator shall also provide
or make available to the Depositor a copy of the above described written report,
to the following address: Lehman Brothers Inc., 745 Seventh Avenue, 7th Floor,
New York, New York 10019, Attention: Michael Hitzmann, or to such other address
as the Depositor may designate.

      (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 or the Securities Administrator, will 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 a Servicer under the applicable Servicing Agreement,
shall use

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reasonable efforts to obtain such information and documentation from such
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 investment in the Certificates; provided,
however, that the Master Servicer shall be entitled to be reimbursed by such
Certificateholder for such Master Servicer's actual expenses incurred in
providing such reports and access.

      (c) Within 90 days, or such shorter period as may be required by statute
or regulation, after the end of each calendar year, the Securities Administrator
shall have prepared and shall make available, upon written request, to each
Person who at any time during the calendar year was a Certificateholder of
record, and make available to Certificate Owners (identified as such by the
Clearing Agency) in accordance with applicable regulations, a report summarizing
the items provided to Certificateholders pursuant to Section 4.03(a) on an
annual basis as may be required to enable such Holders to prepare their federal
income tax returns. Such information shall include the amount of original issue
discount accrued on each Class of Certificates and information regarding the
expenses of the Trust Fund. The Securities Administrator 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 Securities
Administrator with such Mortgage Loan level information as is necessary for the
Securities Administrator to prepare such reports.

      Section 4.04.     Certificate Account.

      (a) The Securities Administrator shall establish and maintain in its name,
as securities administrator, a trust account (the "Certificate Account"), to be
held in trust for the benefit of the Certificateholders until disbursed pursuant
to the terms of this Agreement. The Certificate Account shall be an Eligible
Account. If the existing Certificate Account ceases to be an Eligible Account,
the Securities Administrator shall establish a new Certificate Account that is
an Eligible Account within 20 Business Days and transfer all funds on deposit in
such existing Certificate Account into such new Certificate Account. The
Certificate Account shall relate solely to the Certificates 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 Securities Administrator held under this Agreement.

      (b) The Securities Administrator shall 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 Securities Administrator all such amounts. The
Securities Administrator shall make withdrawals from the Certificate Account
only for the following purposes:

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

            (ii) to pay itself the Securities Administrator Fee and any
      investment income earned with respect to funds in the Certificate Account
      invested in Eligible Investments as set forth in subsection (c) below, and
      to make payments to itself, the Trustee and others prior to making
      distributions pursuant to Section 5.02 for any expenses or other

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      indemnification owing to itself, the Trustee and others pursuant to any
      provision of this Agreement;

            (iii) to make payments of the Master Servicing Fee (to the extent
      not already withheld or withdrawn from the Collection Account by the
      Master Servicer) to the Master Servicer;

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

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

      (c) The Securities Administrator may invest, or cause to be invested,
funds held in the Certificate Account, which funds, if invested, shall be
invested in Eligible Investments (which may be obligations of the Securities
Administrator). All such investments must mature no later than 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 Securities
Administrator (in its capacity as such) or its nominee. All income and gain
realized from any such investment shall be paid to the Securities Administrator
and shall be subject to its withdrawal on order from time to time. The amount of
any losses incurred in respect of any such investments shall be paid by the
Securities Administrator 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 that are not invested shall be held in
cash.

      Section 4.05.     Determination of LIBOR.

      (a) If the outstanding Certificates include any LIBOR Certificates, then
on each LIBOR Determination Date the Securities Administrator shall determine
LIBOR on the basis of the offered LIBOR quotations of the Reference Banks as of
11:00 a.m. London time on such LIBOR Determination Date as follows:

            (i) If on any LIBOR Determination Date two or more of the Reference
      Banks provide such offered quotations, LIBOR for the next Accrual Period
      will be the arithmetic mean of such offered quotations (rounding such
      arithmetic mean if necessary to the nearest five decimal places);

            (ii) If on any LIBOR Determination Date only one or none of the
      Reference Banks provides such offered quotations, LIBOR for the next
      Accrual Period will be whichever is the higher of (x) LIBOR as determined
      on the previous LIBOR Determination Date or (y) the Reserve Interest Rate.
      The "Reserve Interest Rate" will be either (A) the rate per annum which
      the Securities Administrator determines to be the arithmetic mean
      (rounding such arithmetic mean if necessary to the nearest five decimal
      places) of the one-month Eurodollar lending rates that New York City banks
      selected by the Depositor are quoting, on the relevant LIBOR Determination
      Date, to the principal London offices of at least two leading banks in the
      London interbank market or (B) in the event that the Securities
      Administrator can determine no such arithmetic mean, the lowest one-month
      Eurodollar lending rate that the New York City banks selected by the
      Depositor are quoting on such LIBOR Determination Date to leading European
      banks; and

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<PAGE>

            (iii) If on any LIBOR Determination Date the Securities
      Administrator is required but is unable to determine the Reserve Interest
      Rate in the manner provided in paragraph (ii) above, LIBOR for the next
      Accrual Period will be LIBOR as determined on the previous LIBOR
      Determination Date or, in the case of the first LIBOR Determination Date,
      the Initial LIBOR Rate.

      (b) The establishment of LIBOR by the Securities Administrator and the
Securities Administrator's subsequent calculation of the Certificate Interest
Rate (or Rates) applicable to the LIBOR Certificates for the relevant Accrual
Period, in the absence of manifest error, will be final and binding. In all
cases, the Securities Administrator may conclusively rely on quotations of LIBOR
for the Reference Banks as such quotations appear on the display designated
"LIBOR" on the Bloomberg Financial Markets Commodities News.

      (c) As used herein, "Reference Banks" shall mean four leading banks
engaged in transactions in Eurodollar deposits in the international Eurocurrency
market (i) with an established place of business in London, England, (ii) whose
quotations appear on the "Bloomberg Screen LIBOR Index Page" (as described in
the definition of LIBOR) on the applicable LIBOR Determination Date and (iii)
which have been designated as such by the Depositor and are able and willing to
provide such quotations to the Depositor on each LIBOR Determination Date. The
Reference Banks initially shall be: Barclay's plc, Bank of Tokyo, National
Westminster Bank and Trust Company and Bankers Trust Company. If any of the
initial Reference Banks should be removed from the Bloomberg Screen LIBOR Index
Page or in any other way fail to meet the qualifications of a Reference Bank,
the Depositor shall use its best efforts to designate alternate Reference Banks.

      (d) If (i) with respect to any LIBOR Determination Date LIBOR is
determined pursuant to clause (a)(iii) of this Section and (ii) on the next
succeeding LIBOR Determination Date LIBOR would, without giving effect to this
paragraph (d), be determined pursuant to such clause (a)(iii), then the
Depositor shall select an alternative interest rate index over which the
Depositor has no control that is used for determining Eurodollar lending rates
and is calculated and published (or otherwise made available) by an independent
third party, and such alternative interest rate index shall constitute LIBOR for
all purposes hereof.

                                   ARTICLE V

                    DISTRIBUTIONS TO HOLDERS OF CERTIFICATES

      Section 5.01.     Distributions Generally.

      (a) Subject to Section 7.01 with respect to the final distribution on the
Certificates, 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 check mailed to each Certificateholder's address as it appears on the
Certificate Register of the Certificate Registrar or, upon written request made
to the Securities Administrator at least five Business Days prior to the related
Distribution Date to any Certificateholder, by wire transfer in immediately
available funds to an account specified in the request and at the expense of
such Certificateholder; provided, however, that the final distribution in
respect of any Certificate shall be made only upon presentation and

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surrender of such Certificate at the Corporate Trust Office. Wire transfers may
be made at the expense of the Holder requesting such wire transfer by deducting
a wire transfer fee from the related distribution. 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 Certificate and at such
time such final payment in retirement of the Residual Certificate will be made
only upon presentation and surrender of such Certificate at the Corporate Trust
Office of the Certificate Registrar. If any payment required to be made on the
Certificates 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.

      (b) 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 Certificate Principal Amounts (or initial Notional
Amounts).

      Section 5.02.     Distributions from the Certificate Account.

      (a) On each Distribution Date, the Securities Administrator (or any
successor Paying Agent on behalf of the Trustee) shall withdraw from the
Certificate Account, to the extent of funds available therefor, the Available
Distribution Amount (excluding all Prepayment Penalty Amounts) with respect to
each Mortgage Pool, and shall distribute such amount in the following order of
priority based on the report of the Securities Administrator:

            (i) from the Available Distribution Amount for each Mortgage Pool,
      to each Class of Senior Certificates in the related Certificate Group, the
      Accrued Certificate Interest thereon for such Distribution Date, as
      reduced by such Class's allocable share of any Net Prepayment Interest
      Shortfalls for the related Mortgage Pool for such Distribution Date;
      provided, however, that any shortfall in available amounts for a Mortgage
      Pool shall be allocated among the Classes of the related Certificate Group
      in proportion to the amount of Accrued Certificate Interest (as so
      reduced) that would otherwise be distributable thereon; and provided,
      further, however, that payments that would otherwise be made to the Class
      3-AX or Class 3-PAX Certificates may be made to the Class 3-A1, Class
      3-A2, Class B1-I, Class B2-I, Class B3-I, Class B4-I, Class B5-I, Class
      B6-I and Class B7-I Certificates, each in respect of any Basis Risk
      Shortfalls and Unpaid Basis Risk Shortfalls as set forth in Section
      5.02(j).

            (ii) from the remaining Available Distribution Amount for each
      Mortgage Pool, to each Class of Senior Certificates in the related
      Certificate Group, any related Interest Shortfall for such Distribution
      Date; provided, however, that any shortfall in available amounts for each
      Mortgage Pool shall be allocated among the Classes of the related
      Certificate Group in proportion to the Interest Shortfall (as so reduced)
      for each such Class on such Distribution Date;

            (iii) from the remaining Available Distribution Amount for each
      Mortgage Pool, to the Senior Certificates of the related Certificate Group
      in reduction of the Class Principal Amounts thereof, concurrently, as
      follows:

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<PAGE>

                  (A) to the Class R, Class 1-A1 and Class 1-A2 Certificates
            from the Available Distribution Amount for Pool 1, the Senior
            Principal Distribution Amount for such Mortgage Pool, in reduction
            of their Class Principal Amounts, sequentially as follows:

                        (I) first, to the Class R Certificate, until its Class
                  Principal Amount has been reduced to zero; and

                        (II) second, pro rata, to the Class 1-A1 and Class 1-A2
                  Certificates until their Class Principal Amounts have been
                  reduced to zero;

                  (B) to the Class 2-A Certificates from the Available
            Distribution Amount for Pool 2 for such Distribution Date, the
            Senior Principal Distribution Amount for such Mortgage Pool for such
            Distribution Date, in reduction of its Class Principal Amount until
            its Class Principal Amount has been reduced to zero;

                  (C) pro rata, to the Class 3-A1 and Class 3-A2 Certificates
            from the Available Distribution Amount for Pool 3 for such
            Distribution Date, the Senior Principal Distribution Amount for such
            Mortgage Pool for such Distribution Date, in reduction of their
            Class Principal Amounts until their Class Principal Amounts have
            been reduced to zero;

                  (D) to the Class 4-A Certificates from the Available
            Distribution Amount for Pool 4 for such Distribution Date, the
            Senior Principal Distribution Amount for such Mortgage Pool for such
            Distribution Date, in reduction of its Class Principal Amount until
            its Class Principal Amount has been reduced to zero;

                  (E) to the Class 5-A Certificates from the Available
            Distribution Amount for Pool 5 for such Distribution Date, the
            Senior Principal Distribution Amount for such Mortgage Pool for such
            Distribution Date, in reduction of its Class Principal Amount until
            its Class Principal Amount has been reduced to zero;

                  (F) pro rata, to the Class 6-A1, Class 6-A2 and Class 6-A3
            Certificates from the Available Distribution Amount for Pool 6 for
            such Distribution Date, the Senior Principal Distribution Amount for
            such Mortgage Pool for such Distribution Date, in reduction of their
            Class Principal Amounts until their Class Principal Amounts have
            been reduced to zero; and

            (iv) from the remaining Available Distribution Amount for Mortgage
      Pools 1 through 5, subject to the prior distribution of amounts pursuant
      to Section 5.02(h) in the case of clauses (C), (F), (I), (L), (O), (R) and
      (U) below, to the Group I Subordinate Certificates, in the following order
      of priority:

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<PAGE>

                  (A) to the Class B1-I Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (B) to the Class B1-I Certificates, any Interest Shortfall for
            such Class on such Distribution Date;

                  (C) to the Class B1-I Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (D) to the Class B2-I Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (E) to the Class B2-I Certificates, any Interest Shortfall for
            such Class on such Distribution Date;

                  (F) to the Class B2-I Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (G) to the Class B3-I Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (H) to the Class B3-I Certificates, any Interest Shortfall for
            such Class on such Distribution Date;

                  (I) to the Class B3-I Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (J) to the Class B4-I Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (K) to the Class B4-I Certificates, any Interest Shortfall for
            such Class on such Distribution Date;

                  (L) to the Class B4-I Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate

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            Principal Distribution Amount for such Distribution Date, except as
            provided in Section 5.02(c), until the Class Principal Amount
            thereof has been reduced to zero;

                  (M) to the Class B5-I Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (N) to the Class B5-I Certificates, any Interest Shortfall for
            such Class on such Distribution Date;

                  (O) to the Class B5-I Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (P) to the Class B6-I Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (Q) to the Class B6-I Certificates, any Interest Shortfall for
            such Class on such Distribution Date;

                  (R) to the Class B6-I Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (S) to the Class B7-I Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (T) to the Class B7-I Certificates, any Interest Shortfall for
            such Class on such Distribution Date;

                  (U) to the Class B7-I Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

            (v) from the remaining Available Distribution Amount for Mortgage
      Pool 6, to the Group II Subordinate Certificates, in the following order
      of priority:

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<PAGE>

                  (A) to the Class B1-II Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (B) to the Class B1-II Certificates, any Interest Shortfall
            for such Class on such Distribution Date;

                  (C) to the Class B1-II Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (D) to the Class B2-II Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (E) to the Class B2-II Certificates, any Interest Shortfall
            for such Class on such Distribution Date;

                  (F) to the Class B2-II Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (G) to the Class B3-II Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (H) to the Class B3-II Certificates, any Interest Shortfall
            for such Class on such Distribution Date;

                  (I) to the Class B3-II Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (J) to the Class B4-II Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (K) to the Class B4-II Certificates, any Interest Shortfall
            for such Class on such Distribution Date;

                  (L) to the Class B4-II Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate

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            Principal Distribution Amount for such Distribution Date, except as
            provided in Section 5.02(c), until the Class Principal Amount
            thereof has been reduced to zero;

                  (M) sequentially, to the Class B1-II, Class B2-II, Class B3-II
            and Class B4-II Certificates, from amounts otherwise paid to the
            Class BX-II Certificates pursuant to clause 5.02(a)(v)(N) (without
            regard to the parenthetical therein), the Subordinate Floating Rate
            Certificate Shortfall and Unpaid Subordinate Floating Rate
            Certificate Shortfall for each such Class;

                  (N) to the Class BX-II Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date (less any amounts distributed on such
            Distribution Date pursuant to clause 5.02(a)(v)(M) above);

                  (O) to the Class BX-II Certificates, any Interest Shortfall
            for such Class on such Distribution Date (provided, however, that
            the Class BX-II Certificates shall not be entitled to reimbursement
            for amounts distributed to the Class B1-II, Class B2-II, Class B3-II
            and Class B4-II Certificates in respect of Subordinate Floating Rate
            Certificate Shortfalls or Unpaid Subordinate Floating Rate
            Certificate Shortfalls and such amounts shall be deemed for federal
            income tax purposes as having been distributed to the Class BX-II
            Certificates);

                  (P) to the Class B5-II Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (Q) to the Class B5-II Certificates, any Interest Shortfall
            for such Class on such Distribution Date;

                  (R) to the Class B5-II Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (S) to the Class B6-II Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (T) to the Class B6-II Certificates, any Interest Shortfall
            for such Class on such Distribution Date;

                  (U) to the Class B6-II Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in

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            Section 5.02(c), until the Class Principal Amount thereof has been
            reduced to zero;

                  (V) to the Class B7-II Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (W) to the Class B7-II Certificates, any Interest Shortfall
            for such Class on such Distribution Date;

                  (X) to the Class B7-II Certificates, in reduction of the Class
            Principal Amount thereof, such Class's Subordinate Class Percentage
            of each Subordinate Principal Distribution Amount for such
            Distribution Date, except as provided in Section 5.02(c), until the
            Class Principal Amount thereof has been reduced to zero;

                  (Y) to the Class B8-II Certificates, the Accrued Certificate
            Interest thereon for such Distribution Date, as reduced by such
            Class's allocable share of any Net Prepayment Interest Shortfalls
            for such Distribution Date;

                  (Z) to the Class B8-II Certificates, any Interest Shortfall
            for such Class on such Distribution Date; and

                  (AA) to the Class B8-II Certificates, in reduction of the
            Class Principal Amount thereof, such Class's Subordinate Class
            Percentage of each Subordinate Principal Distribution Amount for
            such Distribution Date, except as provided in Section 5.02(c), until
            the Class Principal Amount thereof has been reduced to zero.

      (b) Net Prepayment Interest Shortfalls for each Mortgage Pool shall be
allocated among the Certificates of the related Certificate Group and the
Subordinate Certificates related to the applicable Mortgage Group
proportionately based on (i) in the case of the related Senior Certificates and
the Group II Subordinate Certificates, the Accrued Certificate Interest
otherwise distributable thereon, and (ii) in the case of the Group I Subordinate
Certificates, interest accrued (at the Underlying Subordinate Rate for the
relevant Mortgage Pool) on their related Apportioned Principal Balances.

      (c) (i) if on any Distribution Date the Credit Support Percentage for the
Class B1-I Certificates is less than the Original Credit Support Percentage for
such Class, then, notwithstanding anything to the contrary in Section 5.02(a),
no distribution of amounts described in clauses (ii) and (iii) of the definition
of Subordinate Principal Distribution Amount will be made in respect of the
Class B2-I, Class B3-I, Class B4-I, Class B5-I, Class B6-I or Class B7-I,
Certificates on such Distribution Date; (ii) if on any Distribution Date the
Credit Support Percentage for the Class B2-I Certificates is less than the
Original Credit Support Percentage for such Class, then, notwithstanding
anything to the contrary in Section 5.02(a), no distribution of amounts
described in clauses (ii) and (iii) of the definition of Subordinate Principal
Distribution Amount will be made in respect of the Class B3-I, Class B4-I, Class
B5-I, Class B6-I or Class B7-I Certificates on such Distribution Date; (iii) if
on any Distribution Date the Credit Support

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<PAGE>

Percentage for the Class B3-I Certificates is less than the Original Credit
Support Percentage for such Class, then, notwithstanding anything to the
contrary in Section 5.02(a), no distribution of amounts described in clauses
(ii) and (iii) of the definition of Subordinate Principal Distribution Amount
will be made in respect of the Class B4-I, Class B5-I, Class B6-I or Class B7-I
Certificates on such Distribution Date; (iv) if on any Distribution Date the
Credit Support Percentage for the Class B4-I Certificates is less than the
Original Credit Support Percentage for such Class, then, notwithstanding
anything to the contrary in Section 5.02(a), no distribution of amounts
described in clauses (ii) and (iii) of the definition of Subordinate Principal
Distribution Amount will be made in respect of the Class B5-I, Class B6-I or
Class B7-I Certificates on such Distribution Date; (v) if on any Distribution
Date the Credit Support Percentage for the Class B5-I Certificates is less than
the Original Credit Support Percentage for such Class, then, notwithstanding
anything to the contrary in Section 5.02(a), no distribution of amounts
described in clauses (ii) and (iii) of the definition of Subordinate Principal
Distribution Amount will be made in respect of the Class B6-I or Class B7-I
Certificates on such Distribution Date; (vi) if on any Distribution Date the
Credit Support Percentage for the Class B6-I Certificates is less than the
Original Credit Support Percentage for such Class, then, notwithstanding
anything to the contrary in Section 5.02(a), no distribution of amounts
described in clauses (ii) and (iii) of the definition of Subordinate Principal
Distribution Amount will be made in respect of the Class B7-I Certificates on
such Distribution Date; (vii) if on any Distribution Date the Credit Support
Percentage for the Class B1-II Certificates is less than the Original Credit
Support Percentage for such Class, then, notwithstanding anything to the
contrary in Section 5.02(a), no distribution of amounts described in clauses
(ii) and (iii) of the definition of Subordinate Principal Distribution Amount
will be made in respect of the Class B2-II, Class B3-II, Class B4-II, Class
B5-II, Class B6-II, Class B7-II or Class B8-II Certificates on such Distribution
Date; (viii) if on any Distribution Date the Credit Support Percentage for the
Class B2-II Certificates is less than the Original Credit Support Percentage for
such Class, then, notwithstanding anything to the contrary in Section 5.02(a),
no distribution of amounts described in clauses (ii) and (iii) of the definition
of Subordinate Principal Distribution Amount will be made in respect of the
Class B3-II, Class B4-II, Class B5-II, Class B6-II, Class B7-II or Class B8-II
Certificates on such Distribution Date; (ix) if on any Distribution Date the
Credit Support Percentage for the Class B3-II Certificates is less than the
Original Credit Support Percentage for such Class, then, notwithstanding
anything to the contrary in Section 5.02(a), no distribution of amounts
described in clauses (ii) and (iii) of the definition of Subordinate Principal
Distribution Amount will be made in respect of the Class B4-II, Class B5-II,
Class B6-II, Class B7-II or Class B8-II Certificates on such Distribution Date;
(x) if on any Distribution Date the Credit Support Percentage for the Class
B4-II Certificates is less than the Original Credit Support Percentage for such
Class, then, notwithstanding anything to the contrary in Section 5.02(a), no
distribution of amounts described in clauses (ii) and (iii) of the definition of
Subordinate Principal Distribution Amount will be made in respect of the Class
B5-II, Class B6-II, Class B7-II or Class B8-II Certificates on such Distribution
Date; (xi) if on any Distribution Date the Credit Support Percentage for the
Class B5-II Certificates is less than the Original Credit Support Percentage for
such Class, then, notwithstanding anything to the contrary in Section 5.02(a),
no distribution of amounts described in clauses (ii) and (iii) of the definition
of Subordinate Principal Distribution Amount will be made in respect of the
Class B6-II, Class B7-II or Class B8-II Certificates on such Distribution Date;
(xii) if on any Distribution Date the Credit Support Percentage for the Class
B6-II Certificates is less than the Original Credit Support Percentage for such
Class, then,

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<PAGE>

notwithstanding anything to the contrary in Section 5.02(a), no distribution of
amounts described in clauses (ii) and (iii) of the definition of Subordinate
Principal Distribution Amount will be made in respect of the Class B7-II or
Class B8-II Certificates on such Distribution Date; and (xiii) if on any
Distribution Date the Credit Support Percentage for the Class B7-II Certificates
is less than the Original Credit Support Percentage for such Class, then,
notwithstanding anything to the contrary in Section 5.02(a), no distribution of
amounts described in clauses (ii) and (iii) of the definition of Subordinate
Principal Distribution Amount will be made in respect of the Class B8-II
Certificates on such Distribution Date;

      Any amount not distributed in respect of any Class on any Distribution
Date pursuant to the immediately preceding paragraph will be allocated among the
remaining related Subordinate Classes in proportion to their respective
Certificate Principal Amounts.

      (d) On each Distribution Date, the Paying Agent shall distribute to the
Holders of the Class P-I Certificates, any Prepayment Penalty Amounts paid by
borrowers upon voluntary full or partial prepayment of the Mortgage Loans in
Pool 1, Pool 2, Pool 4 and Pool 5.

      (e) On each Distribution Date, the Paying Agent shall distribute to the
Holders of the Class P-II Certificates, any Prepayment Penalty Amounts paid by
borrowers upon voluntary full or partial prepayment of the Mortgage Loans in
Pool 3.

      (f) On each Distribution Date, the Paying Agent shall distribute to the
Holders of the Class P-III Certificates, any Prepayment Penalty Amounts paid by
borrowers upon voluntary full or partial prepayment of the Mortgage Loans in
Pool 6.

      (g) On each Distribution Date, the Paying Agent shall distribute to the
Holder of the Class R Certificate any Available Distribution Amount for each of
the Mortgage Pools remaining for such Distribution Date after application of all
amounts described in paragraph (a) and (e) of this Section 5.02. Any
distributions pursuant to this paragraph (g) shall not reduce the Class
Principal Amount of the Class R Certificate.

      (h) (i) (A) On each Distribution Date prior to the Credit Support
Depletion Date but on or after the date on which the aggregate Certificate
Principal Amount of the Senior Certificates of any Certificate Group (other than
the Group 6 Certificates) has been reduced to zero, amounts otherwise
distributable as principal on each Class of Group I Subordinate Certificates in
accordance with the priorities set forth in Section 5.02(a)(iv), in reverse
order of priority, in respect of such Class's Subordinate Class Percentage of
the Subordinate Principal Distribution Amount for the Mortgage Pool relating to
such retired Senior Certificates, shall be distributed as principal to the
Senior Certificates (other than the Group 6 Certificates) remaining outstanding
in accordance with the priorities set forth in Sections 5.02(a)(iv), until the
Class Principal Amounts thereof have been reduced to zero, provided that on such
Distribution Date (a) the Aggregate Subordinate Percentage for such Distribution
Date is less than 200% of the Aggregate Subordinate Percentage as of the Cut-off
Date or (b) the average outstanding principal balance of the Mortgage Loans in
Pool 1 (if the aggregate Certificate Principal

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<PAGE>

Amount of the Senior Certificates of Group 2, Group 3, Group 4 or Group 5 has
been reduced to zero), Pool 2 (if the aggregate Certificate Principal Amount of
the Senior Certificates of Group 1, Group 3, Group 4 or Group 5 has been reduced
to zero), Pool 3 (if the aggregate Certificate Principal Amount of the Senior
Certificates of Group 1, Group 2, Group 4 or Group 5 has been reduced to zero)
or Pool 4 (if the aggregate Certificate Principal Amount of the Senior
Certificates of Group 1, Group 2, Group 3 or Group 5 has been reduced to zero),
Pool 5 (if the aggregate Certificate Principal Amount of the Senior Certificates
of Group 1, Group 2, Group 3 or Group 4 has been reduced to zero), that are
delinquent 60 days or more for the last six months as a percentage of the
related Group Subordinate Amount is greater than or equal to 50%.

                  (A) On each Distribution Date on which the Senior Certificates
            of two or more Certificate Groups remain outstanding, any amounts
            distributable pursuant to this Section 5.02(h)(i) will be
            distributed in proportion to the aggregate Certificate Principal
            Amounts of such Certificates of each such Certificate Group.

            (ii) (A) On any Distribution Date on which any Certificate Group
      (other than the Group 6 Certificates) constitutes an Undercollateralized
      Group, all amounts otherwise distributable as principal on the Group I
      Subordinate Certificates, in reverse order of priority (other than amounts
      necessary to pay unpaid Interest Shortfalls) (or, following the Credit
      Support Depletion Date, such other amounts described in the immediately
      following sentence), will be distributed as principal to the Senior
      Certificates of such Undercollateralized Group in accordance with the
      priorities set forth in Section 5.02(a)(iv), until the aggregate
      Certificate Principal Amount of such Senior Certificates equals the Pool
      Balance of the related Mortgage Pool (such distribution, an
      "Undercollateralization Distribution"). In the event that any Certificate
      Group (other than the Group 6 Certificates) constitutes an
      Undercollateralized Group on any Distribution Date following the Credit
      Support Depletion Date, Undercollateralization Distributions will be made
      from the excess of the Available Distribution Amount for the other such
      Mortgage Pools not related to an Undercollateralized Group (other than
      Pool 6) remaining after all required amounts have been distributed to the
      Senior Certificates of the other Certificate Groups (other than the Group
      6 Certificates). In addition, the amount of any unpaid Interest Shortfalls
      with respect to an Undercollateralized Group (other than the Group 6
      Certificates) on any Distribution Date (including any Interest Shortfalls
      for such Distribution Date) will be distributed to the Senior Certificates
      of such Undercollateralized Group prior to the payment of any
      Undercollateralization Distributions from amounts otherwise distributable
      as principal on the Group I Subordinate Certificates, in reverse order of
      priority (or, following the Credit Support Depletion Date, as provided in
      the preceding sentence).

      (i) If on any Distribution Date two or more Certificate Groups (other than
the Group 6 Certificates) are Undercollateralized Groups and one or more
Certificate Group (other than the Group 6 Certificates) is not an
Undercollateralized Group, the distributions described in paragraph (ii)(A)
above will be made in proportion to the amount by which the aggregate
Certificate Principal Amount of the Senior Certificates, after giving effect to
distributions pursuant to Sections 5.02(a) and (b) on such Distribution Date, of
each such Undercollateralized Group exceeds the Pool Balance of the related
Mortgage Pool for such Distribution Date.

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<PAGE>

      (j) On each Distribution Date on or prior to November 2009, amounts
otherwise payable to the Class 3-AX or Class 3-PAX Certificates pursuant to
Section 5.02(a)(i), if any, will be distributed to the Class 3-A1 and Class 3-A2
and the Group I Subordinate Certificates in respect of any Basis Risk Shortfalls
for such Distribution Date or Unpaid Basis Risk Shortfalls for any prior
Distribution Date with respect to Pool 3. Such amounts will be distributed (i)
first, pro rata, to the Class 3-A1 and Class 3-A2 Certificates and (ii) second,
sequentially, to the Group I Subordinate Certificates in order of priority. The
Class 3-AX and Class 3-PAX Certificates will contribute amounts hereunder pro
rata based on the amount of interest each such Class would otherwise be entitled
to receive on such Distribution Date. The amounts distributed hereunder to the
Class 3-A1 and Class 3-A2 and the Group I Subordinate Certificates with respect
to any Basis Risk Shortfalls or Unpaid Basis Risk Shortfalls with respect to
Pool 3 shall be deemed for federal income tax purposes as having been
distributed to the Class 3-AX and Class 3-PAX Certificates, as applicable. The
Class 3-AX and Class 3-PAX Certificates shall have no right to reimbursement for
such amounts distributed pursuant to this section.

      Section 5.03.     Allocation of Realized Losses.

      (a) (i) On any Distribution Date, the principal portion of each Realized
Loss (other than any Excess Loss) in respect of a Mortgage Loan in Pools 1
through 5 shall be allocated in the following order of priority:

                  first, to the Class B7-I Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  second, to the Class B6-I Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  third, to the Class B5-I Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  fourth, to the Class B4-I Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  fifth, to the Class B3-I Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  sixth, to the Class B2-I Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  seventh, to the Class B1-I Certificates, until the Class
            Principal Amount thereof has been reduced to zero; and

                  eighth, to the Classes of Senior Certificates of the related
            Certificate Group, pro rata, in accordance with their Class
            Principal Amounts; provided, that any such loss allocated to any
            Class of Accrual Certificates shall be allocated (subject to Section
            5.03(c)) on the basis of the lesser of (x) the Class Principal
            Amount thereof immediately prior to the applicable Distribution Date
            and (y) the Class Principal Amount thereof on the Closing Date (as
            reduced by any Realized

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<PAGE>

            Losses previously allocated thereto); provided, however, that any
            Realized Losses otherwise allocable to the Class 1-A1 Certificates
            pursuant to this Section 5.03 shall be allocated to the Class 1-A2
            Certificates until the Class Principal Amount of such Class has been
            reduced to zero, and any Realized Losses otherwise allocable to the
            Class 3-A1 Certificates pursuant to this Section 5.03 shall be
            allocated to the Class 3-A2 Certificates until the Class Principal
            Amount of such Class has been reduced to zero.

Notwithstanding the foregoing, the first $0.10 of principal portion of Realized
Losses in Mortgage Group I shall not be allocated to any Class of Certificates.

            (ii) On any Distribution Date, the principal portion of each
      Realized Loss (other than any Excess Loss) in respect of a Mortgage Loan
      in Pool 6 shall be allocated in the following order of priority:

                  first, to the Class B8-II Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  second, to the Class B7-II Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  third, to the Class B6-II Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  fourth, to the Class B5-II Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  fifth, to the Class B4-II Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  sixth, to the Class B3-II Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  seventh, to the Class B2-II Certificates, until the Class
            Principal Amount thereof has been reduced to zero;

                  eighth, to the Class B1-II Certificates, until the Class
            Principal Amount thereof has been reduced to zero; and

                  ninth, to the Classes of Senior Certificates of the related
            Certificate Group, pro rata, in accordance with their Class
            Principal Amounts; provided, that any such loss allocated to any
            Class of Accrual Certificates shall be allocated (subject to Section
            5.03(c)) on the basis of the lesser of (x) the Class Principal
            Amount thereof immediately prior to the applicable Distribution Date
            and (y) the Class Principal Amount thereof on the Closing Date (as
            reduced by any Realized Losses previously allocated thereto);
            provided, however, that any Realized Losses

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<PAGE>

            otherwise allocable to the Class 6-A2 Certificates pursuant to this
            Section 5.03 shall be allocated to the Class 6-A3 Certificates until
            the Class Principal Amount of such Class has been reduced to zero.

Notwithstanding the foregoing, the first $0.52 of principal portion of Realized
Losses in Pool 6 shall not be allocated to any Class of Certificates.

      (b) With respect to any Distribution Date, the principal portion of any
Excess Loss in respect of a Mortgage Loan shall be allocated, pro rata, to the
Senior Certificates of the related Certificate Group and, if such Mortgage Loan
is in Mortgage Group II, to the Group II Subordinate Certificates on the basis
of their Class Principal Amounts, and, if such Mortgage Loan is in Mortgage
Group I, to the Classes of Group I Subordinate Certificates on the basis of
their Apportioned Principal Balances; provided, that any such loss allocated to
any Class of Accrual Certificates (and any Accrual Component) shall be allocated
(subject to Section 5.03(c)) on the basis of the lesser of (x) the Class
Principal Amount thereof immediately prior to the applicable Distribution Date
and (y) the Class Principal Amount thereof on the Closing Date (as reduced by
any Realized Losses previously allocated thereto).

      (c) Any Realized Losses allocated to a Class of Certificates pursuant to
Section 5.03(a) or (b) shall be allocated among the Certificates of such Class
in proportion to their respective Certificate Principal Amounts. Any allocation
of Realized Losses pursuant to this paragraph (c) shall be accomplished by
reducing the Certificate Principal Amount of the related Certificates on the
related Distribution Date in accordance with Section 5.03(d).

      (d) Realized Losses allocated in accordance with this Section 5.03 shall
be allocated on the Distribution Date in the month following the month in which
such loss was incurred and, in the case of the principal portion thereof, after
giving effect to distributions made on such Distribution Date.

      (e) On each Distribution Date, amounts described in clauses (x) and (y) of
the definition of Subordinate Certificate Writedown Amount for such date shall
effect corresponding reductions in the Certificate Principal Amount of the
lowest ranking Class of outstanding Group I Subordinate Certificates and Group
II Subordinate Certificates, respectively, which reduction shall occur on such
Distribution Date after giving effect to distributions made on such Distribution
Date.

      Section 5.04.     Advances by the Master Servicer and the Securities
                        Administrator.

      (a) Advances shall be made in respect of each Deposit Date as provided
herein. If, on any Determination Date, the Master Servicer determines that any
Scheduled Payments due during the related Due Period (other than Balloon
Payments) have not been received, the Master Servicer shall, or shall cause the
applicable Servicer to, advance such amount on the Master Servicer Remittance
Date immediately following such Determination Date, less an amount, if any, to
be set forth in an Officer's Certificate to be delivered to the Trustee and the
Securities Administrator on such Determination Date, which if advanced the
Master Servicer or such Servicer has determined would not be recoverable from
amounts received with respect to such Mortgage Loan, including late payments,
Liquidation Proceeds, Insurance Proceeds or otherwise.

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<PAGE>

The Securities Administrator shall be able to rely conclusively on any
non-recoverability determination made by the Master Servicer. 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 Securities Administrator from its own funds (or funds advanced by the
applicable Servicer) for deposit in the Securities Administrator 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 Securities
Administrator 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 Securities Administrator for
deposit in the Securities Administrator 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
Securities Administrator shall be entitled to conclusively rely upon any
determination by the Master Servicer that an Advance, if made, would constitute
a non-recoverable advance. The Master Servicer and each Servicer shall be
entitled to be reimbursed from the Collection Account for all Advances made by
it as provided in Section 4.02.

      (b) In the event that the Master Servicer fails for any reason to make an
Advance required to be made pursuant to Section 5.04(a) on or before the Master
Servicer Remittance Date, the Securities Administrator, 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 any
Servicer that would have been deposited in such Certificate Account over (b) the
amount of any Advance made by the Master Servicer or such Servicer with respect
to such Distribution Date; provided, however, that the Securities Administrator
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 Securities
Administrator 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 Servicers. Any Compensating Interest Payments
made by the Servicers shall be a component of the Interest Remittance Amount.

                                   ARTICLE VI

            CONCERNING THE TRUSTEE AND THE SECURITIES ADMINISTRATOR;
                                EVENTS OF DEFAULT

      Section 6.01.     Duties of Trustee and Securities Administrator.

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<PAGE>

      (a) The Trustee, except during the continuance of an Event of Default (of
which a Responsible Officer of the Trustee shall have actual knowledge), and the
Securities Administrator undertakes to perform such duties and only such duties
as are specifically set forth in this Agreement. Any permissive right of the
Trustee or the Securities Administrator provided for in this Agreement shall not
be construed as a duty of the Trustee or the Securities Administrator. If an
Event of Default (of which a Responsible Officer of the Trustee or the
Securities Administrator shall have actual knowledge) has occurred and has not
otherwise been cured or waived, the Trustee or the Securities Administrator
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 unless the Securities Administrator is acting as Master Servicer, in
which case it shall use the same degree of care and skill as the Master Servicer
hereunder.

      (b) Each of the Trustee and the Securities Administrator, upon receipt of
all resolutions, certificates, statements, opinions, reports, documents, orders
or other instruments furnished to the Trustee or the Securities Administrator
which are specifically required to be furnished pursuant to any provision of
this Agreement, shall examine them to determine whether they are in the form
required by this Agreement; provided, however, that neither the Trustee not the
Securities Administrator shall 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, to the Trustee or the
Securities Administrator, as applicable, pursuant to this Agreement, and neither
the Trustee nor the Securities Administrator shall be required to recalculate or
verify any numerical information furnished to the Trustee or the Securities
Administrator pursuant to this Agreement.

      (c) Neither the Trustee nor the Securities Administrator shall have any
liability arising out of or in connection with this Agreement, except for its
negligence or willful misconduct. No provision of this Agreement shall be
construed to relieve the Trustee or the Securities Administrator from liability
for its own negligent action, its own negligent failure to act or its own
willful misconduct; provided, however, that:

            (i) Neither the Trustee nor the Securities Administrator shall be
      personally liable with respect to any action taken, suffered or omitted to
      be taken by it in good faith in accordance with the consent or direction
      of Holders of Certificates 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 Event of Default (other than resulting from a
      failure by the Master Servicer (i) to remit funds (or to make Advances) or
      (ii) to furnish information to the Trustee when required to do so) 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 Corporate Trust Office, and such notice
      references the Holders of the Certificates and this Agreement;

            (iii) For all purposes under this Agreement, the Securities
      Administrator shall not be deemed to have notice of any Event of Default
      (other than resulting from a failure by the Master Servicer to remit funds
      or to furnish information to the Securities

                                       97
<PAGE>

      Administrator when required to do so) unless a Responsible Officer of the
      Securities Administrator has actual knowledge thereof or unless written
      notice of any event which is in fact such a default is received by the
      Securities Administrator at the address provided in Section 11.07, and
      such notice references the Holders of the Certificates and this Agreement;
      and

            (iv) With respect to amounts that would be treated as "unanticipated
      expenses" within the meaning of Treasury Regulations Section
      1.860G-1(b)(3)(ii) if paid or reimbursed by the REMICs hereunder, no
      provision of this Agreement shall require the Trustee or the Securities
      Administrator 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 or the Securities Administrator to perform, or be
      responsible for the manner of performance of, any of the obligations of
      the Master Servicer under this Agreement except, with respect to the
      Securities Administrator, during such time, if any, as the Securities
      Administrator 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.

      (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 use its best efforts to remit to the Master Servicer upon
receipt any such complaint, claim, demand, notice or other document (i) which is
delivered to the Corporate Trust Office of the Trustee, (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) Neither the Trustee or the Securities Administrator shall 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 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 the
Securities Administrator, as applicable, or exercising any trust or power
conferred upon the Trustee or the Securities Administrator, as applicable, under
this Agreement.

      (f) Neither the Trustee nor the Securities Administrator shall be held
liable by reason of any insufficiency in any account (including without
limitation the Securities Administrator Account and the Certificate Account)
held by or on behalf of the Trustee or the Securities Administrator 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).

      (g) Except as otherwise provided herein, neither the Trustee nor the
Securities Administrator shall have any duty (A) to see to any recording,
filing, or depositing of this Agreement or any agreement referred to herein or
any financing statement or continuation

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statement evidencing a security interest, or to see to the maintenance of any
such recording or filing or depositing or to any re-recording, re-filing or
re-depositing of any thereof, (B) to see to any insurance, (C) to see to 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 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 delivered to the
Trustee or the Securities Administrator pursuant to this Agreement believed by
the Trustee or the Securities Administrator, as applicable, to be genuine and to
have been signed or presented by the proper party or parties.

      (h) Neither the Securities Administrator nor the Trustee shall be liable
in its individual capacity for an error of judgment made in good faith by a
Responsible Officer or other officers of the Trustee or the Securities
Administrator, as applicable, unless it shall be proved that the Trustee or the
Securities Administrator, as applicable, was negligent in ascertaining the
pertinent facts.

      (i) Notwithstanding anything in this Agreement to the contrary, neither
the Securities Administrator nor the Trustee shall 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 or the Securities
Administrator , as applicable, has been advised of the likelihood of such loss
or damage and regardless of the form of action.

      (j) Neither the Securities Administrator nor the Trustee shall be
responsible for the acts or omissions of the other or any Servicer, Custodian or
the Master Servicer, it being understood that this Agreement shall not be
construed to render any of them agents of one another.

      Section 6.02.     Certain Matters Affecting the Trustee and the Securities
                        Administrator.

      Except as otherwise provided in Section 6.01:

            (i) Each of the Trustee and the Securities Administrator may
      request, and may rely and shall be protected in acting or refraining from
      acting upon any resolution, Officer's Certificate, certificate of
      auditors, Opinion of Counsel 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;

            (ii) Each of the Trustee and the Securities Administrator 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;

            (iii) Neither the Trustee nor the Securities Administrator shall 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;

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            (iv) Unless an Event of Default shall have occurred and be
      continuing, neither the Trustee nor the Securities Administrator shall 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 Holders of at least a majority in Class Principal
      Amount (or Class Notional Amount) of each Class of Certificates; provided,
      however, that, if the payment within a reasonable time to the Trustee or
      the Securities Administrator, as applicable, 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 or the Securities Administrator, as applicable, may require
      reasonable indemnity against such expense or liability or payment of such
      estimated expenses as a condition to proceeding. The reasonable expense
      thereof shall be paid by the Holders requesting such investigation;

            (v) Each of the Trustee and the Securities Administrator 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 and the Securities
      Administrator, respectively, conferred on them by such appointment
      provided that each of the Trustee and the Securities Administrator shall
      continue to be responsible for its duties and obligations hereunder to the
      extent provided herein, and provided further that neither the Trustee nor
      the Securities Administrator shall be responsible for any misconduct or
      negligence on the part of any such agent or attorney appointed with due
      care by the Trustee or the Securities Administrator, as applicable;

            (vi) Neither the Trustee nor the Securities Administrator shall 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 or the Securities Administrator, as applicable, reasonable
      security or indemnity against the costs, expenses and liabilities which
      may be incurred therein or thereby;

            (vii) The right of the Trustee and the Securities Administrator to
      perform any discretionary act enumerated in this Agreement shall not be
      construed as a duty, and neither the Trustee nor the Securities
      Administrator shall be answerable for other than its negligence or willful
      misconduct in the performance of such act; and

            (viii) Neither the Trustee nor the Securities Administrator shall be
      required to give any bond or surety in respect of the execution of the
      Trust Fund created hereby or the powers granted hereunder.

      Section 6.03.     Trustee and Securities Administrator Not Liable for
                        Certificates.

      The Trustee and the Securities Administrator make no representations as to
the validity or sufficiency of this Agreement or any Custodial Agreement, of the
Certificates (other than the

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certificate of authentication on the Certificates), or of any Mortgage Loan or
Servicing Agreement, or related document save that the Trustee and the
Securities Administrator each represent 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. Neither the
Trustee nor the Securities Administrator shall 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. Neither the Trustee nor the Securities
Administrator shall be responsible for the legality or validity of this
Agreement, the Custodial Agreements or the Servicing Agreements or the validity,
priority, perfection or sufficiency of the security for the Certificates issued
or intended to be issued hereunder. Except as otherwise provided herein, neither
the Trustee nor the Securities Administrator shall have any 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 and Securities Administrator May Own
                        Certificates.

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

      Section 6.05.     Eligibility Requirements for Trustee and Securities
                        Administrator.

      Each of the Trustee and the Securities Administrator hereunder shall at
all times be (i) an institution insured by the FDIC and (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. 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 either the Trustee or the Securities Administrator shall cease to be
eligible in accordance with provisions of this Section, the Trustee or the
Securities Administrator, as applicable, shall resign immediately in the manner
and with the effect specified in Section 6.06.

      Section 6.06.     Resignation and Removal of Trustee and Securities
                        Administrator.

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

      (b) If at any time (i) either the Trustee or the Securities Administrator
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 or the Securities Administrator shall become incapable of acting, or
shall be adjudged a bankrupt or insolvent, or a receiver of the Trustee or the
Securities Administrator or of either of their property shall be appointed, or
any public officer shall take charge or control of the Trustee or the Securities
Administrator or of either of their 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, or (iv) the continued use of the
Trustee or the Securities Administrator would result in a downgrading of the
rating by the Rating Agencies of any Class of Certificates with a rating, then
the Depositor shall remove the Trustee or the Securities Administrator, as
applicable, and appoint a successor trustee or successor securities
administrator, as applicable, by written instrument, one copy of which
instrument shall be delivered to the Trustee or the Securities Administrator, as
applicable, so removed, one copy to the successor trustee or the successor
securities administrator, as applicable, and one copy to the Master Servicer.

      (c) The Holders of more than 50% of the Class Principal Amount (or Class
Notional Amount) of each Class of Certificates may at any time upon 30 days'
written notice to the Trustee, the Securities Administrator and the Depositor
remove the Trustee or the Securities Administrator 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 or
Securities Administrator, as applicable, so removed and one copy to the Master
Servicer; the Depositor shall thereupon use its best efforts to appoint a
mutually acceptable successor trustee or successor securities administrator, as
applicable, in accordance with this Section.

      (d) Any resignation or removal of the Trustee or Securities Administrator
and appointment of a successor trustee or successor securities administrator
pursuant to any of the provisions of this Section shall become effective upon
acceptance of appointment by the successor trustee or successor securities
administrator, as applicable, as provided in Section 6.07.

      Section 6.07.     Successor Trustee and Successor Securities
                        Administrator.

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      (a) Any successor trustee or successor securities administrator appointed
as provided in Section 6.06 shall execute, acknowledge and deliver to the
Depositor, the Master Servicer and to its predecessor trustee or predecessor
securities administrator, as applicable, an instrument accepting such
appointment hereunder, and thereupon the resignation or removal of the
predecessor trustee or predecessor securities administrator, as applicable,
shall become effective and such successor trustee or successor securities
administrator, as applicable, 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 or
securities administrator, as applicable, herein. The predecessor trustee or
predecessor securities administrator, as applicable shall deliver to the
successor trustee (or assign to the successor trustee its interest under each
Custodial Agreement, to the extent permitted thereunder) or predecessor
securities administrator, as applicable, all Mortgage Files and documents and
statements related to each Mortgage Files 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 record 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 or
predecessor securities administrator, as applicable, 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 or securities
administrator, as applicable all such rights, powers, duties and obligations.

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

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

      Section 6.08.     Merger or Consolidation of Trustee or Securities
                        Administrator.

      Any Person into which the Trustee or Securities Administrator may be
merged or with which it may be consolidated, or any Person resulting from any
merger, conversion or consolidation to which the Trustee or Securities
Administrator shall be a party, or any Persons succeeding to the business of the
Trustee or the Securities Administrator, shall be the successor to the Trustee
or the Securities Administrator 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.

      Section 6.09.     Appointment of Co-Trustee, Separate Trustee or
                        Custodian.

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      (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 Class Notional Amount) of each Class of Certificates shall
each have the power from time to time to appoint one or more Persons 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 obligation of
the Trustee to make Advances pursuant to Section 5.04 and 6.14 hereof shall not
be affected or assigned by the appointment of a co-trustee.

      (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 moneys 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;

            (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

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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.

      (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. The Trustee shall not
be responsible for any action or inaction of any separate trustee, co-trustee or
custodian. 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 Trust Fund shall pay the reasonable compensation of the
co-trustees to the extent, and in accordance with the standards, specified in
Section 6.12 hereof (which compensation shall not reduce any compensation
payable to the Trustee under such Section).

      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.
The Trustee hereby appoints the Securities Administrator to act as the initial
Authenticating Agent, and the Securities Administrator hereby accepts such
appointment. 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.

      (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.

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      (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 to the extent provided in Section
6.12.

      Section 6.11.     Indemnification of Trustee and Securities Administrator.

      The Trustee and the Securities Administrator and their respective
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 Certificates, the Mortgage
Loan Sale Agreement, any Custodial Agreement or any Servicing 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 or the Securities
      Administrator, as applicable, shall have given the Depositor, the Master
      Servicer and the Holders written notice thereof promptly after the Trustee
      or the Securities Administrator, as applicable, shall have knowledge
      thereof; provided that failure to so notify shall not relieve the Trust
      Fund of the obligation to indemnify the Trustee or the Securities
      Administrator;

            (ii) while maintaining control over its own defense, the Trustee or
      the Securities Administrator, as applicable, 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 or the Securities Administrator, as applicable, entered into
      without the prior consent of the Depositor, which consent shall not be
      unreasonably withheld; and

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<PAGE>

            (iv) any such loss, liability or expense indemnified by the Trust
      Fund must constitute an "unanticipated expense" within the meaning of
      Treasury Regulations Section 1.860G-1(b)(3)(ii).

      The provisions of this Section 6.11 shall survive any termination of this
Agreement and the resignation or removal of the Trustee or the Securities
Administrator, as applicable, 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 Securities Administrator, Trustee
                        and Custodian.

      The Securities Administrator shall be entitled to (a) the Securities
Administrator Fee, and is authorized to pay itself the amount of income or gain
earned from investment of funds in the Securities Administrator Account and (b)
reimbursement of all reasonable expenses, disbursements and advancements
incurred or made by the Securities Administrator in accordance with this
Agreement (including fees and expenses of its counsel and all persons not
regularly in its employment), except any such expenses, disbursements and
advancements that either (i) arise from its negligence, bad faith or willful
misconduct or (ii) do not constitute "unanticipated expenses" within the meaning
of Treasury Regulations Section 1.860G-1(b)(3)(ii). The Trustee shall be
compensated as separately agreed with the Securities Administrator. The
Custodian shall be compensated as separately agreed with the Depositor.

      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 amount, it may
withdraw such request.

      Section 6.14.     Events of Default; Securities Administrator 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 the Securities
      Administrator the Mortgage Loan data sufficient to prepare the reports
      described in 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
      the Securities Administrator or to such Master Servicer, the Securities
      Administrator and the Trustee by the Holders of not less than 25% of the
      Class Principal Amount (or Class Notional Amount) of each Class of
      Certificates affected thereby; or

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            (ii) 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 such Master Servicer contained in this Agreement
      which continues unremedied for a period of 30 days (or 15 days, in the
      case of a failure to maintain any Insurance Policy required to be
      maintained pursuant to this Agreement) after the date on which written
      notice of such failure, requiring the same to be remedied, 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 (or Class Notional Amount) of each Class of Certificates affected
      thereby; or

            (iii) 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

            (iv) 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 such Master Servicer or of or
      relating to all or substantially all of its property; or

            (v) 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

            (vi) 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

            (vii) 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
      60 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
      not less than 25% of the Aggregate Certificate Principal Amount of each
      Class of Certificates; or

            (viii) A sale or pledge of the 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 and

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      Certificateholders holding more than 50% of the Class Principal Amount (or
      Class Notional Amount) of each Class of Certificates; or

            (ix) The Master Servicer has notice or actual knowledge that any
      Servicer at any time is not either an FNMA- or FHLMC-approved
      Seller/Servicer, and the Master Servicer has not terminated the rights and
      obligations of such Servicer under the applicable Servicing Agreement and
      replaced such Servicer with an FNMA- or FHLMC-approved servicer within 60
      days of the date the Master Servicer receives such notice or actual
      knowledge; or

            (x) Any failure of the Master Servicer to remit to the Securities
      Administrator any payment required to be made to the Securities
      Administrator for the benefit of Certificateholders under the terms of
      this Agreement, including any Advance, on any Master Servicer Remittance
      Date, which such failure continues unremedied after 1:00 p.m. Eastern
      Standard Time one Business Day after the date upon which notice of such
      failure shall have been given to the Master Servicer and the Trustee by
      the Securities Administrator.

      If an Event of Default described in clauses (i) through (ix) of this
Section 6.14 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 6.14, 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 (or
Class Notional 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 (x) of this Section 6.14 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 (x) 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 Securities Administrator and upon receipt of written
notice by the Securities Administrator from the Trustee pursuant to and under
the terms of this Agreement; and the Securities Administrator 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 and the Securities Administrator in effecting the
termination of the defaulting Master Servicer's responsibilities and rights
hereunder as Master Servicer including, without limitation, notifying Servicers
of the assignment of the master servicing function and providing the Securities
Administrator or its designee all documents and records in electronic or other
form reasonably requested by it to enable the Securities Administrator or its
designee to assume the defaulting Master Servicer's functions hereunder and the
transfer to the Securities Administrator for administration by it of all amounts
which shall at the time be or should have been deposited by

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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 shall bear all costs of a master servicing
transfer, including but not limited to those of the Trustee and Securities
Administrator 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. The Securities Administrator
shall be entitled to be reimbursed from the Master Servicer (or by the Trust, if
the Master Servicer is unable to fulfill its obligations hereunder) for all
costs associated with the transfer of servicing from the predecessor Master
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 Securities
Administrator to correct any errors or insufficiencies in the servicing data or
otherwise to enable the Securities Administrator 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 and the Securities
Administrator shall be entitled to withdraw such reimbursement from amounts on
deposit in the Certificate Account pursuant to Section 4.04; provided that the
terminated Master Servicer shall reimburse the Trust for any such expense
incurred by the Trust; 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(i), (ii), (iii), (iv), (v), (vi), (vii), (ix)
and (xi) to the extent such reimbursement relates to the period prior to such
Master Servicer's termination.

      If any Event of Default shall occur of which a Responsible Officer of the
Trustee has actual knowledge, the Trustee, upon becoming aware of the occurrence
thereof through the proper execution of its duties under this Agreement, shall
promptly notify the Securities Administrator and the Rating Agencies of the
nature and extent of such Event of Default. The Trustee or the Securities
Administrator shall immediately give written notice to the Master Servicer upon
such Master Servicer's failure to remit funds on the Master Servicer Remittance
Date.

      (b) On and after 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 and within a period of time not to exceed 90 days after
the Securities Administrator receives written notice from the Trustee pursuant
to Section 6.14(a) or Section 9.28, the Securities Administrator, 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 or
the Trustee's failure to provide information required by this Agreement shall
not be considered a default by the Securities

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Administrator hereunder. In addition, the Securities Administrator 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 Securities Administrator receives written notice from the
Trustee pursuant to Section 6.14(a) or Section 9.28, as applicable. The
Securities Administrator shall have no liability relating to the representations
and warranties of the Master Servicer set forth in Section 9.14. In the
Securities Administrator's capacity as such successor, the Securities
Administrator shall have the same limitations on liability herein granted to the
Master Servicer. As compensation therefor, the Securities Administrator shall be
entitled to receive all compensation payable to the Master Servicer under this
Agreement, including the Master Servicing Fee. The Securities Administrator
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 master servicing data as may be required by
the Securities Administrator to correct any errors or insufficiencies in the
master servicing data or otherwise to enable the Securities Administrator to
master service the Mortgage Loans properly and effectively.

      (c) Notwithstanding the above, the Securities Administrator may, if it
shall be unwilling to continue to so act, or shall, if it is unable to so act,
request the Trustee to appoint, 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 a master servicer, like the
Master Servicer. Any entity designated by the Trustee or the Securities
Administrator as a successor master servicer may be an Affiliate of the Trustee
or the Securities Administrator; provided, however, that, unless such Affiliate
meets the net worth requirements and other standards set forth herein for a
successor master servicer, the Trustee or the Securities Administrator, 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 or the Securities Administrator 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, the Securities Administrator 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, the Securities Administrator
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 Securities Administrator 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, the Securities Administrator 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

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Certificates or thereafter be received with respect to the Mortgage Loans.
Neither the Trustee, the Securities Administrator 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 Securities
Administrator as required by this Agreement or (iv) restrictions imposed by any
regulatory authority having jurisdiction over the Master Servicer. Neither the
Securities Administrator 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 terminated Master Servicer to deliver, or any delay in delivering
cash, documents or records to it, or (ii) the failure of the terminated Master
Servicer to cooperate as required by this Agreement.

      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.

      35% or more 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 Securities Administrator and the
Certificateholders at their respective addresses appearing on the Certificate
Register. 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

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thereof to the Securities Administrator and the Certificateholders, unless such
Event of Default shall have been cured or waived prior to the issuance of such
notice and within such 45-day period.

      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 Class Notional Amount) of each Class of
Certificates 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 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. 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 Securities Administrator, the Master Servicer or a
Certificateholder.

      Section 6.20.     Preparation of Tax Returns and Other Reports.

      (a) 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 U.S.
Securities and Exchange Commission (the "Commission") as in effect from time to
time (the "Rules")) following each Distribution Date, the Securities
Administrator shall, in accordance with industry standards and the Rules,
prepare and file with the Commission via the Electronic Data Gathering and
Retrieval System (EDGAR), a Form 8-K (or such other form as is prescribed by the
Rules) that includes (i) a copy of the statement to the Certificateholders for
such Distribution Date and (ii) such other information as is required by the
Rules and available to the Securities Administrator in a format compatible with
Edgar filing

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requirements. Prior to January 30 in the first year, unless it has received
prior instructions from the Depositor not to do so, the Securities Administrator
shall, in accordance with industry standards, prepare and file a Form 15
Suspension Notification with respect to the Trust Fund, if applicable. Prior to
March 30, 2006 and, unless and until a Form 15 Suspension Notification shall
have been filed, on or prior to March 30 of each year thereafter, the Securities
Administrator shall file (but will not execute) a Form 10-K, in substance
conforming to industry standards and complying with the Rules, with respect to
the Trust Fund. The Form 10-K shall include the certification required pursuant
to Rule 13a-14 under the Securities and Exchange Act of 1934, as amended (the
"Form 10-K Certification") signed by an appropriate party or parties (which Form
10-K Certification the Securities Administrator shall not be required to prepare
or sign) and such other information as is required by the Rules. The Securities
Administrator shall promptly send copies of each periodic report filed on Form
8-K or other applicable form, each annual report on Form 10-K, and each Form 15
Suspension Notification, together in each case with the acceptance confirmation
receipt from EDGAR, to McKee Nelson LLP and to the Depositor (i) by e-mail to
the e-mail addresses provided in writing by each of McKee Nelson LLP and the
Depositor, respectively and (ii) to McKee Nelson LLP at 1919 M Street, N.W.,
Washington, D.C. 20036, and to the Depositor at the address specified in Section
11.07, in each case to the attention of a designated contact specified by each
of McKee Nelson LLP and the Depositor, respectively. The Securities
Administrator shall have no liability for any delay in filing the Form 10-K or
Form 10-K Certification due to the failure of any party to sign such Form 10-K
or Form 10-K Certification. The Depositor hereby grants to the Securities
Administrator a limited power of attorney to execute and file each Form 8-K (or
other applicable form for filing of periodic reports). Such power of attorney
shall continue until either the earlier of (i) receipt by the Securities
Administrator from the Depositor of written termination of such power of
attorney or (ii) the termination of the Trust Fund. The Depositor agrees to
promptly furnish to the Securities Administrator, from time to time upon
request, such further information, reports, and financial statements within its
control related to this Agreement and the Mortgage Loans as the Securities
Administrator reasonably deems appropriate to prepare and file all necessary
reports with the Commission. The Securities Administrator shall have no
responsibility to file any items other than those specified in this Section
6.20(a).

      (b) If so requested, the Securities Administrator shall sign a
certification (in the form attached hereto as Exhibit M) for the benefit of the
Person(s) signing the Form 10-K Certification regarding certain aspects of such
Form 10-K Certification (provided, however, that the Securities Administrator
shall not be required to undertake an analysis of, and shall have no
responsibility for, any financial information, accountant's report,
certification or other matter contained therein, except for computations
performed by the Securities Administrator and reflected in distribution
reports), which certification shall be delivered to such Person(s) not later
than five Business Days prior to the date on which the Form 10-K is required to
be filed with the Commission.

      (c) If so requested, the Master Servicer shall sign a certification for
the benefit of the Person(s) signing the Form 10-K Certification regarding
certain aspects of such Form 10-K Certification (provided, however, that the
Master Servicer shall not be required to undertake an analysis of the
accountant's report attached as an exhibit to the Form 10-K).

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      (d) 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.

      Section 6.21.     Reporting Requirements of the Commission.

      The Securities Administrator and the Master Servicer shall reasonably
cooperate with the Depositor and its counsel to enter into such amendments or
modifications to the Agreement as may be necessary to comply with the Rules and
any interpretation thereof by the staff of the Commission, subject to the
provisions of Section 11.03 hereof.

                                  ARTICLE VII

                            PURCHASE AND TERMINATION
                                OF THE TRUST FUND

      Section 7.01.     Termination of Trust Fund Upon Repurchase or Liquidation
                        of All Mortgage Loans.

      (a) The respective obligations and responsibilities of the Trustee, the
Securities Administrator and the Master Servicer created hereby (other than the
obligation of the Trustee to make payments to Certificateholders as set forth in
Section 7.02, the obligation of the Master Servicer to make a final remittance
to the Securities Administrator for deposit into the Certificate Account
pursuant to Section 4.01 and the obligations of the Master Servicer to the
Securities Administrator and the Trustee pursuant to Sections 9.10 and 9.14),
shall terminate on the earlier 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 and (ii) the sale of all remaining property held by the Trust Fund
in accordance with Section 7.01(b); 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. Any termination of the Trust Fund shall be carried out in such a manner
so that the termination of each REMIC included therein shall qualify as a
"qualified liquidation" under the REMIC Provisions.

      (b) On any Distribution Date occurring after the date on which (x) the
total Scheduled Principal Balance of the Mortgage Loans in Pools 1 through 5 is
less than 10% of the Scheduled Principal Balance of the Mortgage Loans in Pool
1, Pool 2, Pool 3, Pool 4 and Pool 5 (in the aggregate) as of the Cut-off Date
or (y) the total Scheduled Principal Balance of the Mortgage Loans in Pool 6 is
less than 1% of the Scheduled Principal Balance of the Mortgage Loans in Pool 6
as of the Cut-off Date, the Master Servicer, with the consent of the Seller
(which consent will not be unreasonably withheld), may, upon written direction
to the Trustee, cause the Trustee to sell (or arrange for the sale of) the
assets of (x) Pool 1, Pool 2, Pool 3, Pool 4 and Pool 5 (in the aggregate) or
(y) Pool 6, respectively, and thereby effect the retirement of the related

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Certificates. Upon the repurchase of such Mortgage Loans, the Master Servicer
shall, upon written direction to the Trustee, cause each of REMIC I-1, REMIC
I-2, REMIC I-3 and REMIC I-4 (in the case of a sale of the assets described in
clause (x) above) or each of REMIC II-1 or REMIC II-2 (in the case of a sale of
the assets described in clause (y) above) to adopt a plan of complete
liquidation pursuant to Section 7.03 hereof to sell all of its property. The
property of the applicable Pool or Pools shall be sold at a price (the
"Repurchase Price") equal to: (i) 100% of the unpaid principal balance of each
Mortgage Loan in such Pool or Pools on the day of such purchase plus interest
accrued thereon at the applicable Mortgage Rate with respect to any such
Mortgage Loan to the Due Date in the Due Period immediately preceding such
Distribution Date, (ii) the fair market value of any applicable REO Property and
any other applicable property (reduced, in the case of REO Property, by (x)
reasonably anticipated disposition costs and (y) any amount by which the fair
market value as so reduced exceeds the outstanding principal balance of the
related Mortgage Loan), such fair market value to be determined by an appraiser
or appraisers appointed by the Master Servicer with the consent of the Trustee
and (iii) any unreimbursed Servicing Advances with respect to each applicable
Mortgage Loan. The Master Servicer and each Servicer (or the Trustee, if
applicable) shall be reimbursed from the Repurchase Price for any Mortgage Loan
or related REO Property for any Advances or Servicing Advances made with respect
to the Mortgage Loans that are reimbursable to the Master Servicer under this
Agreement or to each Servicer under the related Servicing Agreement (or to the
Trustee hereunder), together with any accrued and unpaid compensation and any
other amounts due to the Master Servicer and the Trustee hereunder or the
Custodians or the Servicers under their respective Custodial or Servicing
Agreements, provided that any such compensation or other amount to be paid to
the Custodians and any such other amounts to be paid to the Servicers are
"unanticipated expenses" within the meaning of Treasury Regulation Section
1.860G-1(b)(3)(ii). The Trustee shall distribute the assets of the applicable
Pool or Pools on the Distribution Date on which the repurchase occurred. Upon
the repurchase of all of the Mortgage Loans, the Trust Fund shall terminate in
accordance with the terms of this Agreement.

      Section 7.02.     Procedure Upon Termination of Trust Fund.

      (a) Notice of any termination of the Trust Fund (or the retirement of the
Certificates related to Mortgage Group I or Mortgage Group II, as applicable)
pursuant to the provisions of Section 7.01, specifying the Distribution Date
upon which the final distribution shall be made, shall be given promptly by the
Trustee by first class mail to the applicable Certificateholders mailed (x) no
later than five Business Days after the Trustee has received notice from the
Master Servicer of its intent to exercise its right to cause the termination of
the Trust Fund pursuant to Section 7.01(b) (or the retirement of the
Certificates related to Mortgage Group I or Mortgage Group II, as applicable, to
the extent the other such Mortgage Group is not terminated pursuant to such
Section 7.01(b)) or (y) upon the final payment or other liquidation of the last
Mortgage Loan or REO Property in the Trust Fund. Such notice shall specify (A)
the Distribution Date upon which final distribution on the Certificates 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. The Trustee shall give such notice to the Securities
Administrator, the Master Servicer, the Depositor and the Certificate Registrar
at the time such notice is given to Holders of the Certificates. Upon any

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such termination of the entire Trust Fund, the duties of the Certificate
Registrar with respect to the applicable Certificates 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 related Certificates, subject to the
Trustee's obligation hereunder to hold all amounts payable to Certificateholders
in trust without interest pending such payment.

      (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 and the Securities
Administrator in connection with any termination or liquidation of the Trust
Fund (or a Mortgage Group thereof) shall be paid from proceeds received from the
liquidation of the Trust Fund, but only to the extent that such expenses
constitute "unanticipated expenses" within the meaning of Treasury Regulations
Section 1.860G-1(b)(3)(ii).

      Section 7.03.     Additional Requirements under the REMIC Provisions.

      (a) Any sale pursuant to Section 7.01(b) shall be effected in accordance
with the following additional requirements, unless the Trustee seeks (at the
request of the Master Servicer), and subsequently receives, an Opinion of
Counsel (at the expense of the Master Servicer), addressed to the Trustee to the
effect that the failure of the Trust Fund to comply with the requirements of
this Section 7.03 will not (i) result in the imposition of taxes on any REMIC
under the REMIC Provisions or (ii) cause any REMIC established hereunder to fail
to qualify as a REMIC at any time that any Certificates are outstanding:

            (i) in the case of a sale of the assets of Mortgage Group I:

                  (A) The Trustee shall sell all of the assets of Mortgage Group
            I for cash and, within 90 days of such sale, shall distribute the
            proceeds of such sale to the Group I Certificateholders in complete
            liquidation of REMIC I-1, REMIC I-2, REMIC I-3 and REMIC I-4; and

                  (B) The Trustee shall attach a statement to the final Federal
            income tax return for each of REMIC I-1, REMIC I-2, REMIC I-3 and
            REMIC I-4 stating that pursuant to Treasury Regulation Section
            1.860F-1, the first day of the 90-day

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            liquidation period for each such REMIC was the date on which the
            Trustee sold such assets; and

            (ii) in the case of a sale of the assets of Mortgage Group II:

                  (A) The Trustee shall sell all of the assets of Mortgage Group
            II for cash and, within 90 days of such sale, shall distribute the
            proceeds of such sale to the Group II Certificateholders in complete
            liquidation of REMIC II-1 and REMIC II-2; and

                  (B) The Trustee shall attach a statement to the final Federal
            income tax return for each of REMIC II-1 and REMIC II-2 stating that
            pursuant to Treasury Regulation Section 1.860F-1, the first day of
            the 90-day liquidation period for each such REMIC was the date on
            which the Trustee sold such assets.

      (b) By its acceptance of a Residual Certificate, each Holder thereof
hereby (i) authorizes the Trustee to take the action described in paragraph (a)
above and (ii) agrees to take such other action as may be necessary to
facilitate liquidation of any REMIC created under this Agreement, which
authorization shall be binding upon all successor Residual Certificateholders.

                                  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 Class Notional Amount) 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

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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 such 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.

      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
Securities Administrator, the Master Servicer, the Certificate Registrar and the
Trustee that neither the Depositor, the Securities Administrator, the Master
Servicer, the Certificate Registrar nor 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

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when such instrument or instruments are delivered to the Trustee, the Securities
Administrator 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, the Securities Administrator
and Master Servicer, if made in the manner provided in this Section. Each of the
Trustee, the Securities Administrator and 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.

      (c) The ownership of Certificates (whether or not such Certificates 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 Securities Administrator, the
Master Servicer and 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 shall bind every future Holder
of the same Certificate and the Holder of every Certificate 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, the
Securities Administrator or the Master Servicer in reliance thereon, whether or
not notation of such action is made upon such Certificate.

                                   ARTICLE IX

                 ADMINISTRATION AND SERVICING OF MORTGAGE LOANS
                             BY THE MASTER SERVICER

      Section 9.01. Duties of the Master Servicer.

      The Certificateholders, by their purchase and acceptance of the
Certificates, 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 applicable Servicing
Agreement.

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      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
Fidelity Bond and an 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 Errors and
Omissions Insurance Policy and the Fidelity Bond shall be in such form and
amount that would meet the requirements of FNMA or FHLMC if it were the
purchaser of the Mortgage Loans. The Master Servicer shall (i) require each
Servicer to maintain an Errors and Omissions Insurance Policy and a Fidelity
Bond in accordance with the provisions of the applicable Servicing Agreement,
(ii) cause each 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 applicable
Servicing Agreement, and (iii) furnish copies of the certificates and notices
referred to in clause (ii) to the Trustee upon its request. The Fidelity Bond
and Errors and Omissions Insurance Policy may be obtained and maintained in
blanket form.

      (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 any Servicer under any such bond or policy shall be
remitted to the Master Servicer to the extent provided in the applicable
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 its annual
unaudited financial statements on or prior to the last day of February of each
year commencing on February 28, 2006. Such financial statements shall include a
balance sheet, income statement, statement of retained earnings, statement of
additional paid-in capital, statement of changes in financial position and all
related notes and schedules and shall be in comparative form, certified by a
nationally recognized firm of Independent Accountants to the effect that such
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.

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      (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 each Servicer shall have full power and
authority (to the extent provided in the applicable 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) 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 applicable Servicing Agreement, as applicable; provided
that the Master Servicer shall not take, or knowingly permit any 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 and 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 any Servicer, when the Master Servicer or a 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
successors 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 any Servicer to
make any modification, waiver or amendment of any term of any Mortgage Loan that
would cause any REMIC included in the Trust Fund to fail to qualify as a REMIC
or result in the imposition of any tax under Section 860F(a) or Section 860G(d)
of the Code. Without limiting the generality of the foregoing, the Master
Servicer in its own name or in the name of a Servicer, and each Servicer, to the
extent such authority is delegated to such Servicer by the Master Servicer under
the applicable Servicing Agreement, is hereby authorized and empowered by the
Trustee when the Master Servicer or a Servicer, as the case may be, believes it
appropriate in its best judgment and in accordance with Accepted Servicing
Practices and the applicable 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
the Master Servicer or a Servicer, upon request, with any powers of attorney
prepared by the Master Servicer or such Servicer empowering the Master Servicer
or such 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 applicable 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 each
Servicer

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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 applicable 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
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, be deemed to be the agent of the
Trustee.

      (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 any Servicer to, in its discretion (i)
waive any late payment charge (but not any Prepayment Penalty Amount, 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 to be made 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 applicable Servicer, reasonably
foreseeable, (2) in the case of a waiver of a Prepayment Penalty Amount if (a)
such Mortgage Loan is in default or default by the related Mortgagor is
reasonably foreseeable, and such waiver would maximize recovery of total
proceeds taking into account the value of such Prepayment Penalty Amount 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 applicable Servicer, reasonably foreseeable, and such
waiver would maximize recovery of total proceeds taking into account the value
of such Prepayment Penalty Amount and the related Mortgage Loan or (ii) the
collection of the Prepayment Penalty Amount would be in violation of applicable
laws or (iii) the collection of such Prepayment Penalty Amount 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 (which opinion shall, if provided by the Master Servicer, be an expense
reimbursed, to the extent it is an unanticipated expense within the meaning of
Treasury Regulation Section 1.860G-1(b)(3)(ii) from the Collection Account
pursuant to Section 4.02(v)) in writing to the effect that such modification,
waiver or amendment would not cause an Adverse REMIC Event; provided, in no
event shall an Opinion of Counsel be required for the waiver of a Prepayment
Penalty Amount under clause (2) above.

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      Section 9.05. Servicing Agreements Between the Master Servicer and
                    Servicers; Enforcement of Servicers' Obligations.

      (a) Each Servicing Agreement requires the applicable 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 such
actions taken or to be taken by a Servicer pursuant to a Servicing Agreement.
Any fees, costs and expenses and other amounts payable to such Servicers shall
be deducted from amounts remitted to the Master Servicer by the applicable
Servicer (to the extent permitted by the applicable Servicing Agreement) and
shall not be an obligation of the Trust, 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 related Servicer is not
required to take under the related Servicing Agreement and (ii) cause a Servicer
to take any action or refrain from taking any action if the related 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 enforce the obligations of each Servicer under the
related Servicing Agreement, and shall use its reasonable best efforts to
enforce the obligations of each Servicer under the related Servicing Agreement
and shall, upon its obtaining actual knowledge of the failure of a Servicer to
perform its obligations in accordance with the related Servicing Agreement, to
the extent that the non-performance of any such obligations would have a
material adverse effect on a Mortgage Loan, the Trust Fund or
Certificateholders, terminate the rights and obligations of such Servicer
thereunder to the extent and in the manner permitted by the related Servicing
Agreement and either act as servicer of the related Mortgage Loans or enter into
a Servicing Agreement with a successor Servicer. Such enforcement, including,
without limitation, the legal prosecution of claims, termination of Servicing
Agreements 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 only (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, to the
extent that such amounts are insufficient to reimburse the Master Servicer for
the costs of such enforcement or (iii) from the Collection Account.

      (d) The Master Servicer shall be entitled to conclusively rely on any
certifications or other information provided by the Servicers under the terms of
the applicable 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.

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      (a) To the extent provided in the applicable Servicing Agreement, the
Master Servicer shall cause each 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 any 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 shall deposit therein any collections of amounts received with respect to
amounts due for taxes, assessments, water rates, Standard Hazard Insurance
Policy premiums 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 applicable Servicing
Agreement. Each Servicer shall be entitled to all investment income not required
to be paid to Mortgagors on any Escrow Account maintained by such Servicer. The
Master Servicer shall make (or cause to be made) to the extent provided in the
applicable 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 has determined that the funds so advanced are
recoverable from escrow payments, reimbursement pursuant to Section 4.02(v) or
otherwise.

      (b) Costs incurred by the Master Servicer or by Servicers 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 expenses within the meaning of Treasury
Regulations Section 1.860G-1(b)(3)(ii) shall be recoverable by the Master
Servicer pursuant to Section 4.02(v).

      Section 9.07. Termination of Servicing Agreements; Successor Servicers.

      (a) The Master Servicer shall be entitled to terminate the rights and
obligations of any Servicer under the applicable Servicing Agreement in
accordance with the terms and conditions of such Servicing Agreement and without
any limitation by virtue of this Agreement; provided, however, that in the event
of termination of any Servicing Agreement by the Master Servicer or the related
Servicer, the Master Servicer shall either act as Servicer of the related
Mortgage Loans, or enter into a Servicing Agreement with a successor Servicer.

      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 each Servicer (or by the Trust Fund, if such
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 Servicer, it will not assume liability
for the representations and warranties of the Servicer, if any, that it
replaces. The Master Servicer shall

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use reasonable efforts to have the successor Servicer assume liability for the
representations and warranties made by the terminated Servicer in respect of the
related Mortgage Loans, 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.

      Section 9.08. Master Servicer Liable for Enforcement.

      Notwithstanding any Servicing Agreement, 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 such
Servicing Agreements or arrangements. 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 each Servicing Agreement for the benefit of
the Certificateholders. The Master Servicer shall be entitled to enter into any
agreement with the Servicers 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 any Servicer in the performance
by such Servicer of its obligations under the related Servicing Agreement.

      Section 9.09. No Contractual Relationship Between Servicers and Trustee or
                    Depositor.

      Any Servicing Agreement that may be entered into and any other
transactions or services relating to the Mortgage Loans involving a Servicer in
its capacity as such and not as an originator shall be deemed to be between such
Servicer, the Seller and the Master Servicer, and the Trustee, the Securities
Administrator and the Depositor shall not be deemed parties thereto and shall
have no claims, rights, obligations, duties or liabilities with respect to such
Servicer except as set forth in Section 9.10 hereof.

      Section 9.10. Assumption of Servicing Agreement by Securities
                    Administrator.

      (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 Securities
Administrator receives written notice from the Trustee pursuant to Section 6.14
or Section 9.28, as applicable, the Securities Administrator shall thereupon
assume all of the rights and obligations of such Master Servicer hereunder and
enforce the rights under each Servicing Agreement entered into with respect to
the Mortgage Loans. The Securities Administrator, its designee or any successor
master servicer appointed by the Securities Administrator or the Trustee shall
be deemed to have assumed all of the Master Servicer's interest herein and
therein to the same extent as if such 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 such
Servicing Agreement accruing prior to its replacement as Master Servicer, and
shall be liable to the Securities Administrator, and hereby agrees to indemnify
and hold harmless the Securities Administrator from and against all costs,
damages, expenses and liabilities (including reasonable attorneys' fees)
incurred by the Securities Administrator as a result of such liability or
obligations of the Master Servicer and in

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connection with the Securities Administrator's assumption (but not its
performance, except to the extent that costs or liability of the Securities
Administrator 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
Securities Administrator against negligent or willful misconduct of the
Securities Administrator.

      (b) The Master Servicer that has been terminated shall, upon request of
the Securities Administrator but at the expense of such Master Servicer or at
the expense of the Trust Fund, deliver to the assuming party all documents and
records relating to each 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 each Servicing Agreement
to the assuming party.

      Section 9.11. "Due - on - Sale" Clauses; Assumption Agreements.

      (a) To the extent provided in the applicable Servicing Agreement, to the
extent Mortgage Loans contain enforceable due-on-sale clauses, and to the extent
that the Master Servicer has knowledge of the conveyance of a Mortgaged
Property, the Master Servicer shall use its reasonable best efforts to cause the
Servicers to enforce such clauses in accordance with the applicable 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 applicable
Servicing Agreement, and, as a consequence, a Mortgage Loan is assumed, the
original Mortgagor may be released from liability in accordance with the
applicable Servicing Agreement.

      (b) The Master Servicer or the related Servicer, as the case may be, shall
be entitled to approve a request from a Mortgagor for the granting of an
easement thereon in favor of another Person or any alteration or demolition of
the related Mortgaged Property if it has determined, exercising its good faith
business judgment in the same manner as it would if it were the owner of the
related Mortgage Loan, that the security for, and the timely and full
collectability of, such Mortgage Loan would not be materially adversely affected
thereby. Any fee collected by the Master Servicer or the related Servicer for
processing such a request will be retained by the Master Servicer or such
Servicer as additional servicing compensation.

      Section 9.12. Release of Mortgage Files.

      (a) Upon (i) becoming aware of the payment in full of any Mortgage Loan,
(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, or (iii)
in the case of a Mortgage Loan as to which the related Mortgaged Property is
located in California, receipt by the Master Servicer of notification from the
applicable Servicer that the Servicer reasonably expects that payment in full
will be received promptly, the Master Servicer will, or will cause the
applicable 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 or to be 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 the Trustee or the
applicable Custodian, to deliver to the applicable

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Servicer the related Mortgage File. In lieu of sending a hard copy certification
of a Servicing Officer, the Master Servicer may, or may cause the Servicer to,
deliver the request for release in a mutually agreeable electronic format. To
the extent that such a request, on its face, originates from a Servicing
Officer, no signature shall be required. Upon receipt of such certification and
request, the Trustee or the applicable Custodian, shall promptly release the
related Mortgage File to the applicable Servicer and neither the Trustee nor the
Custodian shall have any further responsibility with regard to such Mortgage
File. The Master Servicer is authorized, and each Servicer, to the extent such
authority is delegated to such Servicer by the Master Servicer under the
applicable 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.

      (b) From time to time and as appropriate for the servicing or foreclosure
of, or other legal proceedings relating to, any Mortgage Loan and in accordance
with Accepted Servicing Practices and the applicable Servicing Agreement, the
Trustee shall execute such pleadings, request for trustee's sale or other
documents as shall be prepared and furnished to the Trustee by the Master
Servicer, or by a Servicer (in form reasonably acceptable to the Trustee) and as
are necessary to the prosecution of any such proceedings. The Trustee or the
Custodian, shall, upon request of the Master Servicer, or of a Servicer, and
delivery to the Trustee or the applicable Custodian, of a trust receipt signed
by a Servicing Officer substantially in the form annexed hereto as Exhibit C or
in the form annexed to the applicable Custodial Agreement as Exhibit C, release
the related Mortgage File held in its possession or control to the Master
Servicer (or the applicable Servicer). Such trust receipt shall obligate the
Master Servicer or applicable Servicer to return the Mortgage File to the
Trustee or Custodian, as applicable, when the need therefor by the Master
Servicer or applicable Servicer no longer exists unless (i) the Mortgage Loan
shall be liquidated, in which case, upon receipt of a certificate of a Servicing
Officer similar to that herein above specified, the trust receipt shall be
released by the Trustee or the Custodian, as applicable, to the Master Servicer
(or the applicable Servicer) or (ii) the Mortgage File has been delivered
directly or through a Servicer to an attorney, or to a public trustee or other
public official as required by law, for purposes of initiating or pursuing legal
action or other proceedings for the foreclosure of the Mortgaged Property either
judicially or non-judicially, and the Master Servicer has delivered directly or
through a Servicer to the Trustee a certificate of a Servicing Officer
certifying as to the name and address of the Person to which such Mortgage File
or such document was delivered and the purpose or purposes of such delivery.

      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 applicable Servicer
to transmit, to the Trustee such documents and instruments coming into the
possession of the Master Servicer or such Servicer from time to time as are
required by the terms hereof to be delivered to the Trustee including notifying
the Trustee (or the applicable Custodian) and the Securities Administrator in
the event that any Mortgagor of any Employee Mortgage Loan ceases to be an

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employee of Lehman Brothers Inc. or its Affiliates. Any funds received by the
Master Servicer or by a Servicer in respect of any Mortgage Loan or which
otherwise are collected by the Master Servicer or by a Servicer as a Subsequent
Recovery, 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 each Servicer to retain its Servicing Fee and other amounts
as provided in the applicable Servicing Agreement. The Master Servicer shall,
and shall (to the extent provided in the applicable Servicing Agreement) cause
each 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.

      (b) All Mortgage Files and funds collected or held by, or under the
control of, the Master Servicer, or any Servicer, in respect of any Mortgage
Loans, whether from the collection of principal and interest payments or from a
Subsequent Recovery, Liquidation Proceeds or Insurance Proceeds, shall be held
by the Master Servicer, or by such 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 each
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 such
Servicer under this Agreement or the applicable Servicing Agreement and shall be
authorized to remit such funds to the Securities Administrator 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, a Servicer or the Master Servicer
that are collected by such 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 a Subsequent
Recovery, 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 such Servicer is entitled under the applicable 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 any Servicer shall be held by the Master
Servicer or such Servicer for and on

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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 laws.

      (d) The Master Servicer agrees that it shall not, and shall not authorize
any 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,
the Securities Administrator 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
      jurisdiction of its formation, 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;

            (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;

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            (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 an FNMA- and FHLMC- 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;
      and

            (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.

      (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, the Securities
Administrator 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). 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). It is understood and
agreed that the enforcement of the obligation of the Master Servicer set forth
in this Section to indemnify the Depositor, the Securities Administrator and the
Trustee as provided in this Section constitutes the sole remedy (other than as
set forth in Section 6.14) of the Depositor, the Securities Administrator 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.

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      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, the Securities Administrator 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(a)(i) through (vi) shall survive the
execution and delivery of this Agreement. The Depositor shall indemnify the
Master Servicer and hold it 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(a)(i) through (vi). 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 of the Master Servicer respecting a breach by the
Depositor of the representations and warranties in Sections 2.03(a)(i) through
(vi).

      Any cause of action against the Depositor relating to or arising out of
the breach of the representations and warranties made in Sections 2.03(a)(i)
through (vi) shall accrue upon discovery of such breach by either the Depositor
or the Master Servicer or notice thereof by any one of such parties to the other
parties.

      Section 9.15. Closing Certificate and Opinion.

      On or before the Closing Date, the Master Servicer shall cause to be
delivered to the Depositor and Lehman Brothers Inc. an Opinion 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 (other than a Cooperative Loan), the Master
Servicer shall maintain, or cause to be maintained by each Servicer, standard
fire and casualty insurance and, where applicable, flood insurance, all in
accordance with the provisions of this Agreement and the related Servicing
Agreement, as applicable. It is understood and agreed that such insurance shall
be with insurers meeting the eligibility requirements set forth in the
applicable 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 any Servicer, under any insurance policies maintained pursuant to this
Section 9.16 (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 Master Servicer's or the Servicer's normal servicing
procedures and Accepted Servicing Practices) shall be deposited into the
Collection Account, subject to withdrawal pursuant to Section 4.02. Any cost
incurred by the Master

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Servicer or any 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 such Servicer pursuant to Section 4.02(v).

      Section 9.17. Presentment of Claims and Collection of Proceeds.

      The Master Servicer shall, or shall cause each Servicer (to the extent
provided in the applicable 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 a Servicer and remitted to the
Master Servicer) in respect of such policies or bonds shall be promptly
deposited in the Collection Account upon receipt, except that any amounts
realized that are to be applied to the repair or restoration of the related
Mortgaged Property or release to the Mortgagor in accordance with the Master
Servicer's or the Servicer's normal servicing procedures need not be so
deposited (or remitted).

      Section 9.18. Maintenance of the Primary Mortgage Insurance Policies.

      (a) The Master Servicer shall not take, or knowingly permit any Servicer
(consistent with the applicable Servicing Agreement) to take, any action that
would result in non-coverage under any applicable Primary Mortgage Insurance
Policy of any loss which, but for the actions of such Master Servicer or
Servicer, would have been covered thereunder. To the extent that coverage is
available, the Master Servicer shall use its best reasonable efforts to keep in
force and effect, or to cause each Servicer to keep in force and effect (to the
extent that the Mortgage Loan requires the Mortgagor to maintain such
insurance), primary mortgage insurance applicable to each Mortgage Loan in
accordance with the provisions of this Agreement and the related Servicing
Agreement, as applicable. The Master Servicer shall not, and shall not permit
any Servicer to, cancel or refuse to renew any such Primary Mortgage Insurance
Policy that is in effect at the date of the initial issuance of the Certificates
and is required to be kept in force hereunder except as required by a applicable
law or in accordance with the provisions of this Agreement and the related
Servicing Agreement, as applicable.

      (b) The Master Servicer agrees to present, or to cause each Servicer to
present, on behalf of the Trustee and the Certificateholders, claims to the
insurer under any Primary Mortgage Insurance Policies and, in this regard, to
take such reasonable action as shall be necessary to permit recovery under any
Primary Mortgage Insurance Policies respecting defaulted Mortgage Loans.
Pursuant to Section 4.01, any amounts collected by the Master Servicer or any
Servicer under any Primary Mortgage Insurance Policies shall be deposited in the
Collection Account, subject to withdrawal pursuant to Section 4.02.

      Section 9.19. Trustee To Retain Possession of Certain Insurance Policies
                    and Documents.

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      The Trustee (or the applicable Custodian, as directed by the Trustee),
shall retain possession and custody of the originals of the Primary Mortgage
Insurance Policies or certificate of insurance if applicable and any
certificates of renewal as to the foregoing as may be issued from time to time
as contemplated by this Agreement. Until all amounts distributable in respect of
the Certificates have been distributed in full and the Master Servicer otherwise
has fulfilled its obligations under this Agreement, the Trustee (or the
applicable Custodian, as directed by the Trustee) shall also retain possession
and custody of each Mortgage File in accordance with and subject to the terms
and conditions of this Agreement. The Master Servicer shall promptly deliver or
cause to be delivered to the Trustee (or the applicable Custodian, as directed
by the Trustee), upon the execution or receipt thereof the originals of the
Primary Mortgage Insurance Policies and any certificates of renewal thereof, and
such other documents or instruments that constitute portions of the Mortgage
File that come into the possession of the Master Servicer from time to time.

      Section 9.20. Realization Upon Defaulted Mortgage Loans.

      The Master Servicer shall use its reasonable best efforts to, or to cause
each Servicer to, foreclose upon, repossess or otherwise comparably convert the
ownership of Mortgaged Properties securing such of the Mortgage Loans as come
into and continue in default and as to which no satisfactory arrangements can be
made for collection of delinquent payments, all in accordance with the
applicable Servicing Agreement. Alternatively, the Master Servicer may take, or
authorize any Servicer to take, other actions in respect of a defaulted Mortgage
Loan, which may include (i) accepting a short sale (a payoff of the Mortgage
Loan for an amount less than the total amount contractually owed in order to
facilitate a sale of the Mortgaged Property by the Mortgagor) or permitting a
short refinancing (a payoff of the Mortgage Loan for an amount less than the
total amount contractually owed in order to facilitate refinancing transactions
by the Mortgagor not involving a sale of the Mortgaged Property), (ii) arranging
for a repayment plan or (iii) agreeing to a modification in accordance with
Section 9.04. In connection with such foreclosure or other conversion or action,
the Master Servicer shall, consistent with Section 9.18, follow such practices
and procedures as it shall reasonably determine to be in the best interests of
the Trust Fund and the Certificateholders and which shall be consistent with its
customary practices in performing its general mortgage servicing activities;
provided that the Master Servicer shall not be liable in any respect hereunder
if the Master Servicer is acting in connection with any such foreclosure or
other conversion or action in a manner that is consistent with the provisions of
this Agreement. Neither the Master Servicer, nor any Servicer, shall be required
to expend its own funds or incur other reimbursable charges in connection with
any foreclosure, or attempted foreclosure which is not completed, or toward the
correction of any default on a related senior mortgage loan, or towards the
restoration of any property unless it shall determine (i) that such restoration
and/or foreclosure will increase the proceeds of liquidation of the Mortgage
Loan to the Certificateholders after reimbursement to itself for such expenses
or charges and (ii) that such expenses and charges will be recoverable to it
through Liquidation Proceeds or Insurance Proceeds (as provided in Section
4.02).

      Section 9.21. Compensation to the Master Servicer.

      The Master Servicer shall (i) be entitled, at its election, either (a) to
pay itself the Master Servicing Fee, in respect of the Mortgage Loans out of any
Mortgagor payment on account of

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interest prior to the deposit of such payment in the Collection Account it
maintains or (b) to withdraw from the Collection Account the Master Servicing
Fee to the extent permitted by Section 4.02(iv). The Master Servicer shall also
be entitled, at its election, either (a) to pay itself the Master Servicing Fee
in respect of each delinquent Mortgage Loan master serviced by it out of
Liquidation Proceeds in respect of such Mortgage Loan or other recoveries with
respect thereto to the extent permitted in Section 4.02 or (b) to withdraw from
the Collection Account it maintains the Master Servicing Fee in respect of each
Liquidated Mortgage Loan to the extent of such Liquidation Proceeds or other
recoveries, 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 Penalty Amount) shall be retained
by the Master Servicer (or the applicable 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(b).

      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, to the extent
provided in the applicable Servicing Agreement, cause the applicable Servicer to
sell, any REO Property as expeditiously as possible and in accordance with the
provisions of this Agreement and the related 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 applicable Servicer
to protect and conserve, such REO Property in the manner and to such extent
required by the applicable 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 any Servicer, in connection with
the operation of any REO Property in the Collection Account.

      (c) The Master Servicer and the applicable Servicer, upon the final
disposition of any REO Property, shall be entitled to reimbursement for any
related 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 any Servicer shall have
hereunder) any such unreimbursed Advances as well as any unpaid 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.

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      (d) The Liquidation Proceeds from the final disposition of the REO
Property, net of any payment to the Master Servicer and the applicable 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 the Master
Servicer shall provide written notice to the Securities Administrator upon such
deposit) and be remitted by wire transfer in immediately available funds to the
Trustee for deposit into the Certificate Account on the next succeeding Master
Servicer Remittance Date.

      Section 9.23. [Reserved].

      Section 9.24. Reports to the Trustee and the Securities Administrator.

      (a) Not later than 30 days after each Distribution Date, the Master
Servicer shall forward to the Trustee and the Securities Administrator 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 to the Depositor, Attention:
Contract Finance, and, upon request, any Certificateholders (or by the
Securities Administrator at the Master Servicer's expense if the Master Servicer
shall fail to provide such copies (unless (i) the Master Servicer shall have
failed to provide the Securities Administrator with such statement or (ii) the
Securities Administrator shall be unaware of the Master Servicer's failure to
provide such statement)).

      (b) Not later than two Business Days following each Distribution Date, the
Master Servicer shall deliver to the 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 Servicers 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 Servicers without independent verification thereof and
the Master Servicer shall be entitled to rely on such information.

      (d) The Master Servicer shall provide the Securities Administrator with
such information as the Securities Administrator may reasonably request in
connection with its responsibilities under Section 10.01 hereof.

      Section 9.25. Annual Officer's Certificate as to Compliance.

      (a) The Master Servicer shall deliver to the Trustee, the Securities
Administrator and the Rating Agencies five Business Days after March 15 of each
year commencing in March 2006, an Officer's Certificate, certifying that with
respect to the period ending on the

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immediately preceding December 31; (i) such Servicing Officer has reviewed the
activities of such Master Servicer during the preceding calendar year or portion
thereof and its performance under this Agreement; (ii) to the best of such
Servicing Officer's knowledge, based on such review, such Master Servicer has
performed and fulfilled its duties, responsibilities and obligations under this
Agreement in all material respects throughout such year, or, if there has been a
default in the fulfillment of any such duties, responsibilities or obligations,
specifying each such default known to such Servicing Officer and the nature and
status thereof; (iii) nothing has come to the attention of such Servicing
Officer to lead such Servicing Officer to believe that any Servicer has failed
to perform any of its duties, responsibilities and obligations under its
Servicing Agreement in all material respects throughout such year, or, if there
has been a material default in the performance or fulfillment of any such
duties, responsibilities or obligations, specifying each such default known to
such Servicing Officer and the nature and status thereof; (iv) the Master
Servicer has received from each Servicer such Servicer's annual certificate of
compliance and a copy of such Servicer's annual audit report, in each case to
the extent required under the applicable Servicing Agreement, or, if any such
certificate or report has not been received by the Master Servicer, the Master
Servicer is using its best reasonable efforts to obtain such certificate or
report; and (v) such other additional items as may be required by applicable law
or regulation.

      (b) 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).

      Section 9.26. Annual Independent Accountants' Servicing Report.

      If the Master Servicer has, during the course of any fiscal year, directly
serviced any of the Mortgage Loans, then the Master Servicer at its expense
shall cause a nationally recognized firm of independent certified public
accountants to furnish a statement to the Trustee, the Rating Agencies and the
Depositor on or before the last day of February of each year commencing on
February 28, 2006, to the effect that, with respect to the most recently ended
fiscal year, such firm has examined certain records and documents relating to
the Master Servicer's performance of its servicing obligations under this
Agreement and pooling and servicing and trust agreements in material respects
similar to this Agreement and to each other and that, on the basis of such
examination conducted substantially in compliance with the audit program for
mortgages serviced for FHLMC or the Uniform Single Attestation Program for
Mortgage Bankers or such other attestation program as may be required by
applicable law or regulation, such firm is of the opinion that the Master
Servicer's activities have been conducted in compliance with this Agreement, or
that such examination has disclosed no material items of noncompliance except
for (i) such exceptions as such firm believes to be immaterial, (ii) such other
exceptions as are set forth in such statement and (iii) such exceptions that the
Uniform Single Attestation Program for Mortgage Bankers or the Audit Program for
Mortgages Serviced by FHLMC requires it to report. Copies of such statements
shall be provided to any Certificateholder upon request by the Master Servicer,
or by the Trustee at the expense of the Master Servicer if the Master Servicer
shall fail to provide such copies. If such report discloses exceptions that are
material, the Master

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Servicer shall advise the Trustee whether such exceptions have been or are
susceptible of cure, and will take prompt action to do so.

      To the extent that the Master Servicer receives an Annual Independent
Accountants' Servicing Report from any Servicer, the Master Servicer shall
forward a copy of such report to the Securities Administrator and the Trustee.
If the report is not received from the Servicer, the Trustee may request that
the Master Servicer contact the applicable Servicer to obtain such report. The
Master Servicer will not be liable for the failure of a Servicer to provide such
report.

      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 FNMA or FHLMC 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 or the Trustee or the Securities Administrator 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 and the Securities Administrator. In the event such determination of
ineligibility of the Master Servicer to continue in the capacity of master
servicer is made by the Master Servicer or the Trustee, no such resignation
shall become effective until a period of time not to exceed ninety days after
the Securities Administrator receives written notice thereof from the Trustee
and until the Securities Administrator shall have assumed, or a successor master
servicer shall have been appointed by the Trustee or the Securities
Administrator, as applicable, 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 to the
Depositor.

      Section 9.29. Assignment or Delegation of Duties by the Master Servicer.

      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 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, the Securities
Administrator, the Depositor or the Rating Agencies to delegate or assign to or
subcontract with or authorize or appoint an Affiliate of the Master Servicer to
perform and carry

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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
shall be given promptly by the Master Servicer to the Depositor, the Securities
Administrator 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.

      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) Neither the Master Servicer nor any of the directors, officers,
employees or agents of the Master Servicer 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 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 the Master Servicer 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 his or its
duties hereunder or by reason of reckless disregard of his or its obligations
and duties hereunder. The Master Servicer and any director, officer, employee or
agent of the Master Servicer 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 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

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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. Notwithstanding
anything herein to the contrary, neither the Master Servicer nor the Trustee
shall have any liability for the servicing of the Additional Collateral,
including, without limitation, the perfection, continuation, partial release,
release, termination, realization upon, substitution, foreclosure, sale, or any
other matter with respect to the Additional Collateral, or the enforcement of
the Additional Collateral Servicing Agreement.

      Section 9.31. Indemnification; Third-Party Claims.

      The Master Servicer agrees to indemnify the Depositor, the Securities
Administrator and the Trustee, and hold them harmless against any and all
claims, losses, penalties, fines, forfeitures, legal fees and related costs,
judgments, and any other costs, liability, fees and expenses that the Depositor,
the Securities Administrator and the Trustee may sustain as a result of the
failure of the Master Servicer to perform its duties and master service the
Mortgage Loans in compliance with the terms of this Agreement. The Depositor,
the Securities Administrator 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 Securities Administrator 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.

                                    ARTICLE X

                              REMIC ADMINISTRATION

      Section 10.01. REMIC and Grantor Trust Administration.

      (a) As set forth in the Preliminary Statement hereto, REMIC status shall
be elected in accordance with the REMIC Provisions with respect to each of REMIC
I-1, REMIC I-2, REMIC I-3, REMIC I-4, REMIC II-1 and REMIC II-2. The Trustee
shall make such elections 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. For the purposes of such elections,
each of the REMIC I-1 Regular Interests is hereby designated as a regular
interest in REMIC I-1. Each of the REMIC I-2 Regular Interests is hereby
designated as a regular interest in REMIC I-2. Each of the REMIC I-3 Regular
Interests is hereby designated as a regular interest in REMIC I-3. Each of the
REMIC I-4 Regular Interests is hereby designated as a regular interest in REMIC
I-4. Each of the REMIC II-1 Regular Interests is hereby designated as a regular
interest in REMIC II-1. Each of the REMIC II-2 Regular Interests is hereby
designated as a regular interest in REMIC II-2. The Class LTI1-R Interest is
hereby designated as the sole

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residual interest in REMIC I-1. The Class LTI2-R Interest is hereby designated
as the sole residual interest in REMIC I-2. The Class LTI3-R Interest is hereby
designated as the sole residual interest in REMIC I-3. The REMIC I-4 Residual
Interest is hereby designated as the sole residual interest in REMIC I-4. The
Class LTII1-R Interest is hereby designated as the sole residual interest in
REMIC II-1. The REMIC II-2 Residual Interest is hereby designated as the sole
residual interest in REMIC II-2. The Class R Certificate evidences ownership of
the Class LTI1-R Interest, the Class LTI2-R Interest, the Class LTI3-R Interest,
the REMIC I-4 Residual Interest, the Class LTII1-R Interest and the REMIC II-2
Residual Interest. It is the intention of the parties hereto that the segregated
pool of assets consisting of any collections of Prepayment Penalty Amounts with
respect to Pool 1, Pool 2, Pool 4 and Pool 5 constitute a grantor trust for
federal income tax purposes. The Trustee, by its execution and delivery hereof,
acknowledges the assignment to it of the Grantor Trust I Assets and declares
that it holds and will hold such assets in trust for the exclusive use and
benefit of all present and future Holders of the Class P-I Certificates. The
rights of Holders of the Class P-I Certificates to receive distributions from
the proceeds of the Grantor Trust I Assets and all ownership interests of such
Holders in and to such distributions, shall be as set forth in this Agreement.
It is the intention of the parties hereto that the segregated pool of assets
consisting of any collections of Prepayment Penalty Amounts with respect to Pool
3 constitute a grantor trust for federal income tax purposes. The Trustee, by
its execution and delivery hereof, acknowledges the assignment to it of the
Grantor Trust II Assets and declares that it holds and will hold such assets in
trust for the exclusive use and benefit of all present and future Holders of the
Class P-II Certificates. The rights of Holders of the Class P-II Certificates to
receive distributions from the proceeds of the Grantor Trust II Assets and all
ownership interests of such Holders in and to such distributions, shall be as
set forth in this Agreement. It is the intention of the parties hereto that the
segregated pool of assets consisting of any collections of Prepayment Penalty
Amounts with respect to Pool 6 constitute a grantor trust for federal income tax
purposes. The Trustee, by its execution and delivery hereof, acknowledges the
assignment to it of the Grantor Trust III Assets and declares that it holds and
will hold such assets in trust for the exclusive use and benefit of all present
and future Holders of the Class P-III Certificates. The rights of Holders of the
Class P-III Certificates to receive distributions from the proceeds of the
Grantor Trust III Assets and all ownership interests of such Holders in and to
such distributions, shall be as set forth in this Agreement.

      (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) is the "Latest
Possible Maturity Date".

      (c) The Securities Administrator shall pay any and all tax related
expenses (not including taxes) of each REMIC and each Grantor Trust, including
but not limited to any professional fees or expenses related to audits or any
administrative or judicial proceedings with respect to such REMIC or such
Grantor Trust 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 Securities Administrator in fulfilling its duties hereunder
(including its duties as tax return preparer). The Securities Administrator
shall be entitled to reimbursement from the Certificate Account of the expenses
to the extent (x) provided in clause (i) above and (y) in the case of expenses
relating to a REMIC provided for hereunder, such expenses are "unanticipated
expenses" within the meaning of Treasury Regulations Section 1.860G-1(b)(3)(ii).

      (d) The Securities Administrator shall prepare and file, and the Trustee
shall sign, all of each REMIC's federal and state tax and information returns as
such REMIC's direct

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representative. The Securities Administrator shall prepare and file, and the
Trustee shall sign, all of the tax returns in respect of each Grantor Trust. The
Securities Administrator shall comply with such requirement by filing Form 1041.
The expenses of preparing and filing such returns shall be borne by the
Securities Administrator. If any Disqualified Organization acquires any
Ownership Interest in a Residual Certificate, then the Securities Administrator
will upon request provide to the Internal Revenue Service, and to the persons
specified in Sections 860E(e)(3) and (6) of the Code, such information as
required in Section 860D(a)(6)(B) of the Code needed to compute the tax imposed
under Section 860E(e) of the Code on transfers of residual interests to
disqualified organizations and the Securities Administrator will be reimbursed
by the Trust for all expenses incurred therewith solely from amounts received
for the provision of such information from persons specified in Sections
860E(e)(3) and (6) of the Code.

      (e) The Securities Administrator or its designee shall perform on behalf
of each REMIC and each Grantor Trust all reporting and other tax compliance
duties that are the responsibility of such REMIC or Grantor Trust 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
Securities Administrator 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 and (ii) to the Certificateholders such information or reports as
are required by the Code or REMIC Provisions.

      (f) The Trustee, the Securities Administrator, the Master Servicer and the
Holders of Certificates shall take any action or cause any REMIC hereunder to
take any action necessary to create or maintain the status of such REMIC as a
REMIC under the REMIC Provisions and shall assist each other as necessary to
create or maintain such status. Neither the Trustee, the Securities
Administrator, the Master Servicer nor the Holder of any Residual Certificate
shall take any action, cause any REMIC to take any action or fail to take (or
fail to cause to be taken) any action that, under the REMIC Provisions, if taken
or not taken, as the case may be, could (i) endanger the status of any such
REMIC as a REMIC or (ii) result in the imposition of a tax upon any such REMIC
(including but not limited to the tax on prohibited transactions as defined in
Code Section 860F(a)(2) and the tax on prohibited contributions set forth on
Section 860G(d) of the Code) (either such event, an "Adverse REMIC Event")
unless the Trustee, the Securities Administrator and the Master Servicer have
received an Opinion of Counsel (at the expense of the party seeking to take such
action) to the effect that the contemplated action will not endanger such status
or result in the imposition of such a tax. In addition, prior to taking any
action with respect to any such REMIC or the assets therein, or causing any such
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 Securities Administrator and 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 such REMIC, and no such
Person shall take any such action or cause such REMIC to take any such action as
to which the Trustee, the Securities Administrator or the Master Servicer has
advised it in writing that an Adverse REMIC Event could occur.

      (g) The Securities Administrator shall prepare or cause to be prepared on
behalf of the Trust Fund, based upon information calculated in accordance with
this Agreement pursuant

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to instructions given by the Depositor, the Trustee shall sign and the
Securities Administrator shall file, federal tax returns and appropriate state
income tax returns and such other returns as may be required by applicable law
relating to the Trust Fund, and shall file any other documents to the extent
required by applicable state tax law (to the extent such documents are in the
Securities Administrator's possession). The Securities Administrator 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 Securities
Administrator as the Depositor may reasonably request in writing, and shall
forward to the Trustee for distribution to each Certificateholder such forms and
furnish such information within the control of the Securities Administrator as
are required by the Code and the REMIC Provisions to be furnished to them, and
will prepare and furnish to the Trustee for distribution to Certificateholders
Form 1099 (supplemental tax information) (or otherwise furnish information
within the control of the Securities Administrator) to the extent required by
applicable law. The Master Servicer will indemnify the Securities Administrator
and the Trustee for any liability of or assessment against the Securities
Administrator or the Trustee, as applicable, resulting from any error in any of
such tax or information returns directly resulting from errors in the
information provided by such Master Servicer.

      (h) The Securities Administrator shall prepare and file with the Internal
Revenue Service ("IRS"), on behalf of each REMIC, an application on IRS Form
SS-4. The Securities Administrator, upon receipt from the IRS of the Notice of
Taxpayer Identification Number Assigned for each REMIC, shall promptly forward
copies of such notices to the Trustee, the Master Servicer and the Depositor.
The Securities Administrator will file an IRS Form 8811 for the REMICs created
hereunder. The Trustee shall sign such forms referred to in this Section
10.01(h) as may be required under applicable law.

      (i) 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 Trust taxes are not paid by a Residual
Certificateholder, the Securities Administrator shall pay any remaining REMIC
taxes out of current or future amounts otherwise distributable to the Holder of
the Residual Certificate in 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 such REMIC, as the case may
be.

      (j) The Securities Administrator shall, for federal income tax purposes,
maintain books and records with respect to each REMIC on a calendar year and on
an accrual basis.

      (k) No additional contributions of assets shall be made to any REMIC,
except as expressly provided in this Agreement with respect to Qualified
Substitute Mortgage Loans.

      (l) Neither the Securities Administrator nor the Master Servicer shall
enter into any arrangement by which any REMIC will receive a fee or other
compensation for services.

      (m) Upon the request of any Rating Agency, the Securities Administrator
shall deliver to such Rating Agency an Officer's Certificate stating the
Securities Administrator's compliance with the provisions of this Section 10.01.

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      (n) The Trustee shall provide the Securities Administrator such
information as the Securities Administrator may reasonably request in connection
with its responsibilities under this Section 10.01.

      (o) It is intended that the rights of the Class 3-A1, Class 3-A2, Class
B1-I, Class B2-I, Class B3-I, Class B4-I, Class B5-I, Class B6-I and Class B7-I
Certificates (collectively, the "Basis Risk Shortfall Protected Certificates")
to receive payments in respect of Basis Risk Shortfalls and Unpaid Basis Risk
Shortfalls related to Pool 3 shall be treated as rights in respect of interest
rate cap contracts written by the Class 3-AX and Class 3-PAX Certificateholders
in favor of the holders of the Basis Risk Shortfall Protected Certificates and
shall be accounted for as property separate and apart from the REMIC I-4 Regular
Interests represented by the Basis Risk Shortfall Protected Certificates. This
provision is intended to comply with the requirements of Treasury Regulations
Section 1.860G-2(i) for the treatment of property rights coupled with regular
interests to be separately respected and shall be interpreted consistently with
such regulation. The Holders of the Basis Risk Shortfall Protected Certificates
agree, by their acceptance of such Certificates, that they will take tax
reporting positions that allocate no more than a nominal value to the right to
receive payments in respect of Basis Risk Shortfalls and Unpaid Basis Risk
Shortfalls related to Pool 3. For information reporting purposes, it will be
assumed that such rights have no value. The Holders of the Class 3-AX and Class
3-PAX Certificates agree, by their acceptance of such Certificates, to take tax
reporting positions consistent with allocations by the Holders of the Basis Risk
Shortfall Protected Certificates of no more than a nominal value to the right to
receive payments in respect of Basis Risk Shortfalls and Unpaid Basis Risk
Shortfalls related to Pool 3. For information reporting purposes, it will be
assumed that such rights have no value. Each payment made to the Basis Risk
Shortfall Protected Certificates in respect of Basis Risk Shortfalls and Unpaid
Basis Risk Shortfalls related to Pool 3 shall be treated for federal income tax
purposes as having been distributed to the Class 3-AX and Class 3-PAX
Certificates, as the case may be, and then paid by the holders of the Class 3-AX
or Class 3-PAX Certificates, as the case may be, to the holders of the relevant
Basis Risk Shortfall Protected Certificates. Each holder or beneficial owner of
a Basis Risk Shortfall Protected Certificate, by virtue of its acquisition of
such Certificate or a beneficial interest in such Certificate, agrees to adopt
tax reporting positions consistent with the characterization of payments made to
the Basis Risk Shortfall Protected Certificates in respect of Basis Risk
Shortfalls and Unpaid Basis Risk Shortfalls related to Pool 3 as payments in
respect of interest rate cap agreements written by the holders of the Class 3-AX
and Class 3-PAX Certificates. The parties hereto intend that the REMIC I-4
Regular Interests represented by each of the Class 3-AX and Class 3-PAX
Certificates, together with the related obligations to make payments to the
Basis Risk Shortfall Protected Certificates shall be treated as grantor trusts
under the Code and the provisions hereof shall be interpreted consistently with
this intention. In furtherance of such intention, the Trustee shall (i) furnish
to the holders of the Class 3-AX and Class 3-PAX Certificates information
regarding items of income, gain, loss and deduction of such grantor trusts and
(ii) file or cause to be filed with the Internal Revenue Service Form 1041
(together with any necessary attachments) or such other form as may be
applicable and (iii) comply with such information reporting obligations with
respect to payments from such grantor trusts as may be applicable under the Code
or other applicable tax laws.

      (p) It is intended that the rights of the Subordinate LIBOR Certificates
to receive payments in respect of Subordinate Floating Rate Certificate
Shortfalls and Unpaid Subordinate

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Floating Rate Certificate Shortfalls shall be treated as rights in respect of
interest rate cap contracts written by the Class BX-II Certificateholders in
favor of the holders of the Subordinate LIBOR Certificates and shall be
accounted for as property separate and apart from the REMIC II-2 Regular
Interests represented by the Subordinate LIBOR Certificates. This provision is
intended to comply with the requirements of Treasury Regulations Section
1.860G-2(i) for the treatment of property rights coupled with regular interests
to be separately respected and shall be interpreted consistently with such
regulation. The Holders of the Subordinate LIBOR Certificates agree, by their
acceptance of such Certificates, that they will take tax reporting positions
that allocate no more than a nominal value to the right to receive payments in
respect of Subordinate Floating Rate Certificate Shortfalls and Unpaid
Subordinate Floating Rate Certificate Shortfalls. For information reporting
purposes, it will be assumed that such rights have no value. The Holders of the
Class BX-II Certificates agree, by their acceptance of such Certificates, to
take tax reporting positions consistent with allocations by the Holders of the
Subordinate LIBOR Certificates of no more than a nominal value to the right to
receive payments in respect of Subordinate Floating Rate Certificate Shortfalls
and Unpaid Subordinate Floating Rate Certificate Shortfalls. For information
reporting purposes, it will be assumed that such rights have no value. Each
payment made to the Subordinate LIBOR Certificates in respect of Subordinate
Floating Rate Certificate Shortfalls and Unpaid Subordinate Floating Rate
Certificate Shortfalls shall be treated for federal income tax purposes as
having been distributed to the Class BX-II Certificates in respect of one or
more of the REMIC BX-II Components and then paid by the holders of the Class
BX-II Certificates to the holders of the relevant Subordinate LIBOR
Certificates. Each holder or beneficial owner of a Class BX-II Certificate or
Subordinate LIBOR Certificate, by virtue of its acquisition of such Certificate
or a beneficial interest in such Certificate, agrees to adopt tax reporting
positions consistent with the characterization of payments made to the
Subordinate LIBOR Certificates in respect of Subordinate Floating Rate
Certificate Shortfalls and Unpaid Subordinate Floating Rate Certificate
Shortfalls as payments in respect of interest rate cap agreements written by the
holders of the Class BX-II Certificates. The parties hereto intend that REMIC
BX-II Components represented by the Class BX-II Certificates, together with the
related obligations to make payments to the Subordinate LIBOR Certificates,
shall be treated as a grantor trust under the Code and the provisions hereof
shall be interpreted consistently with this intention. In furtherance of such
intention, the Trustee shall (i) furnish to the holders of the Class BX-II
Certificates information regarding items of income, gain, loss and deduction of
such grantor trust and (ii) file or cause to be filed with the Internal Revenue
Service Form 1041 (together with any necessary attachments) or such other form
as may be applicable and (iii) comply with such information reporting
obligations with respect to payments from such grantor trusts as may be
applicable under the Code or other applicable tax laws.

      Section 10.02. Prohibited Transactions and Activities.

      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 the REMIC holding such Mortgage Loan
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

                                      145
<PAGE>

the Closing Date, unless it has received an Opinion of Counsel (at the expense
of the party causing such sale, disposition, or substitution) that such
disposition, acquisition, substitution, or acceptance will not (a) affect
adversely the status of such REMIC as a REMIC or of the Certificates other than
the Residual Certificates as the regular interests therein, (b) affect the
distribution of interest or principal on the Certificates, (c) result in the
encumbrance of the assets transferred or assigned to the Trust Fund (except
pursuant to the provisions of this Agreement) or (d) cause such REMIC to be
subject to a tax on prohibited transactions or prohibited contributions pursuant
to the REMIC Provisions.

      Section 10.03. Indemnification with Respect to Certain Taxes and Loss of
                     REMIC Status.

      In the event that a REMIC fails to qualify as a REMIC, loses its status as
a REMIC, or incurs federal, state or local taxes as a result of a prohibited
transaction or prohibited contribution under the REMIC Provisions due to the
negligent performance by the Trustee or the Securities Administrator, as
applicable, of its duties and obligations set forth herein, the Trustee or the
Securities Administrator, as applicable, shall indemnify the Holder of the
Residual Certificate against any and all losses, claims, damages, liabilities or
expenses ("Losses") resulting from such negligence; provided, however, that
neither the Trustee nor the Securities Administrator shall be liable for any
such Losses attributable to the action or inaction of the Master Servicer, the
Depositor, 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 or the Securities Administrator, as
applicable, 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 or the Securities Administrator 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, (2) for any Losses other than arising out of a
negligent performance by the Trustee or the Securities Administrator,
respectively, 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).

      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 applicable Servicing Agreement), permit any Servicer to,
rent, lease, or otherwise earn income on behalf of any REMIC with respect to any
REO Property which might cause such REO Property to fail to qualify as
"foreclosure" property within the meaning of section 860G(a)(8) of the Code or
result in the receipt by any REMIC of any "income from non-permitted assets"
within the meaning of section 860F(a)(2) of the Code or any "net income from
foreclosure property" which is subject to tax under the REMIC Provisions unless
the Master Servicer has advised, or has caused the applicable Servicer to
advise, the Trustee and the Securities Administrator in writing to the effect
that, under the REMIC Provisions, such action would not adversely affect the
status of any REMIC as a REMIC and any income generated for such REMIC by the
REO Property would not result in the imposition of a tax upon such REMIC.

                                      146
<PAGE>

      (b) The Master Servicer shall make, or shall cause the applicable Servicer
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 applicable
Servicer to, dispose of any REO Property within three years from the end of the
calendar year of its acquisition by the Trust Fund unless the Trustee has
received a grant of extension from the Internal Revenue Service to the effect
that, under the REMIC Provisions and any relevant proposed legislation and under
applicable state law, the applicable REMIC may hold REO Property for a longer
period without adversely affecting the REMIC status of such REMIC or causing the
imposition of a Federal or state tax upon such REMIC. If the Trustee has
received such an extension , then (a) the Trustee shall provide a copy of such
extension to the Master Servicer and Securities Administrator and (b) the
Trustee, or the Master Servicer, acting on its behalf hereunder, shall, or shall
cause the applicable 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 Trustee has not received such
an extension and the Trustee, or the Master Servicer acting on behalf of the
Trustee hereunder, or the applicable Servicer is unable to sell the REO Property
within 33 months after its acquisition by the Trust Fund or if the Trustee has
received such an extension, and the Trustee, or the Master Servicer acting on
behalf of the Trustee hereunder, is unable to sell the REO Property within the
period ending three months before the close of the Extended Period, the Master
Servicer shall, or shall cause the applicable Servicer to, before the end of the
three year period or the Extended Period, as applicable, (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 Master
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.

                                   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) This Agreement may be amended from time to time by the Depositor, the
Master Servicer, the Securities Administrator and the Trustee, without notice to
or the consent of any of

                                      147
<PAGE>

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 any
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. No such amendment effected
pursuant to the preceding sentence shall, as evidenced by an Opinion of Counsel,
adversely affect the status of any REMIC created pursuant to this Agreement, 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 may require an Opinion of Counsel (at the expense of the
party requesting such amendment) to the effect that such amendment is permitted
under this paragraph. Any such amendment shall be deemed not to adversely affect
in any material respect any Holder, if the Trustee receives written confirmation
from each Rating Agency that such amendment will not cause such Rating Agency to
reduce, qualify or withdraw the then current rating assigned to the Certificates
(and any Opinion of Counsel requested by the Trustee in connection with any such
amendment may rely expressly on such confirmation as the basis therefor).

      (b) This Agreement may also be amended from time to time by the Depositor,
the Master Servicer, the Securities Administrator 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 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, at the expense of the party requesting
the change, that such change will not adversely affect the status of any REMIC
as a REMIC or cause a tax to be imposed on such REMIC; 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 Class Notional Amount) 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) 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 and to the Rating Agencies.

      (d) 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.

                                      148
<PAGE>

      (e) Notwithstanding anything to the contrary in any Servicing Agreement,
the Trustee shall not consent to any amendment of any Servicing Agreement except
pursuant to the standards provided in this Section with respect to amendment of
this Agreement.

      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 Notional
Amount), Certificates owned by the Depositor, the Securities Administrator, the
Master Servicer, the Trustee or any Servicer or Affiliates thereof are not to be
counted so long as such Certificates are owned by the Depositor, the Securities
Administrator, the Master Servicer, the Trustee or any Servicer or Affiliates
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 Certificateholder, upon the request of such
Certificateholder 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) under the Act. Any reasonable, out-of-pocket expenses
incurred by the Trustee or the Securities Administrator in providing such
information shall be reimbursed by the Depositor.

      (b) The Securities Administrator will 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 or Form 10-K filed with the Securities and Exchange Commission
pursuant to Section 6.20(c) and (ii) a copy of any other document incorporated
by reference in the Prospectus to the extent in the possession of the Securities
Administrator. Any reasonable out-of-pocket expenses incurred by the Securities
Administrator in providing copies of such documents shall be reimbursed by the
Depositor.

      (c) [Reserved].

      Section 11.06. Governing Law.

      THIS AGREEMENT SHALL BE CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE
OF NEW YORK, AND THE OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER
SHALL BE DETERMINED IN ACCORDANCE WITH SUCH LAWS WITHOUT REGARD TO CONFLICT OF
LAWS PRINCIPLES APPLIED IN NEW YORK (OTHER THAN SECTION 5-1401 OF THE GENERAL
OBLIGATIONS LAW).

      Section 11.07. Notices.

         All demands, notices and communications hereunder shall be in writing
and shall be deemed to have been duly given when delivered to such party at the
relevant address, facsimile

                                      149
<PAGE>

number or electronic mail address set forth below (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): received
by (a) in the case of the Depositor, Structured Asset Securities Corporation,
745 Seventh Avenue, 7th Floor, New York, New York 10019, Attention: Mark Zusy,
(b) in the case of the Securities Administrator, Wells Fargo Bank, National
Association, P.O. Box 98, Columbia, Maryland 21046 (or, for overnight
deliveries, 9062 Old Annapolis Road, Columbia, Maryland 21045) (SARM 2005-4) or
for purposes of presentment of Certificates for transfer, exchange and/or
payment, the Securities Administrator's Corporate Trust Office, (c) in the case
of the Certificate Registrar, its Corporate Trust Office, (d) in the case of the
Trustee, HSBC Bank USA, National Association, 452 Fifth Avenue, New York, New
York 10018, Attention: Issuer Services and (e) in the case of the Master
Servicer, Aurora Loan Services LLC, 327 Inverness Drive South, Englewood,
Colorado, 80112, Mail Stop Code 3195; Attention: Master Servicing or as to each
party such other address as may hereafter be furnished by such party to the
other parties in writing. Any notice required or permitted to be mailed to a
Holder shall be given by first class mail, postage prepaid, at the address of
such Holder as shown in the Certificate Register. Any notice so mailed within
the time prescribed in this Agreement shall be conclusively presumed to have
been duly given, whether or not the Holder receives such notice.

      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.

      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. Benefits of Agreement.

      Nothing in this Agreement or in the Certificates, express or implied,
shall give to any Person, other than the parties to this Agreement and their
successors hereunder and the Holders of the Certificates, any benefit or any
legal or equitable right, power, remedy or claim under this Agreement, except to
the extent specified in Section 11.14.

                                      150
<PAGE>

      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; and

            (vi) the making of a final payment pursuant to Section 7.02.

      (b) All notices to the Rating Agencies provided for this Section shall be
in writing and sent by first class mail, telecopy or overnight courier, as
follows:

          If to Moody's, to:

          Moody's Investors Service, Inc.
          99 Church Street
          New York, New York 10007

          If to S&P, to:

          Standard & Poor's
          55 Water Street
          New York, New York  10041

      (c) The Securities Administrator shall provide or make available to the
Rating Agencies reports prepared pursuant to Section 4.03. In addition, the
Securities Administrator 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 Securities Administrator.

      Section 11.13. 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 11.14. Transfer of Servicing.

                                      151
<PAGE>

      The Seller agrees that it shall provide written notice to the Trustee, the
Securities Administrator and the Master Servicer thirty days prior to any
transfer or assignment by the Seller of its rights under any Servicing Agreement
or of the servicing thereunder or delegation of its rights or duties thereunder
or any portion thereof to any Person other than the initial Servicer under such
Servicing Agreement; provided that the Seller shall not be required to provide
prior notice of any transfer of servicing that occurs within three months
following the Closing Date to an entity that is a Servicer on the Closing Date.
In addition, the ability of the Seller to transfer or assign its rights and
delegate its duties under a 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
      FNMA or FHLMC;

            (iii) Such successor servicer must satisfy the seller/servicer
      eligibility standards in the applicable Servicing Agreement, exclusive of
      any experience in mortgage loan origination, and must be reasonably
      acceptable to the Master Servicer, whose approval shall not be
      unreasonably withheld;

            (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, the Securities Administrator 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 applicable
      Servicer under the applicable Servicing Agreement or, in the case of a
      transfer of servicing to a party that is already a Servicer pursuant to
      this Agreement, an agreement to add the related Mortgage Loans to the
      Servicing Agreement already in effect with such Servicer;

            (v)   If the successor servicer is not a Servicer of Mortgage Loans
      at the time of such transfer, there must be delivered to the Trustee and
      the Securities Administrator 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;

            (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

                                      152
<PAGE>

      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 a Remittance Date but before the next succeeding Master
      Servicer Remittance Date, to the Master Servicer, all funds held by the
      applicable 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.

                      [SIGNATURE PAGE IMMEDIATELY FOLLOWS]

                                      153
<PAGE>

      IN WITNESS WHEREOF, the Depositor, the Securities Administrator, the
Trustee and the Master Servicer 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:________________________________
                                            Name: Michael C. Hitzmann
                                            Title: Vice President

                                         HSBC BANK USA, NATIONAL ASSOCIATION,
                                           not in its individual capacity, but
                                           solely as Trustee

                                         By:________________________________
                                            Name: Wendy Zhang
                                            Title: Assistant Vice President

                                         WELLS FARGO BANK, NATIONAL
                                           ASSOCIATION,
                                           as Securities Administrator

                                         By:________________________________
                                            Name: Amy Doyle
                                            Title: Vice President

                                         AURORA LOAN SERVICES LLC,
                                           as Master Servicer

                                         By:________________________________
                                            Name: E. Todd Whittemore
                                            Title: Executive Vice President
Solely for purposes of Section 11.14,
accepted and agreed to by:

LEHMAN BROTHERS HOLDINGS INC.

By:________________________________
   Name: Stanley P. Labanowski
   Title: Senior Vice President

<PAGE>

                                    EXHIBIT A

                              FORMS OF CERTIFICATES

                             [Intentionally Omitted]

                                      A-1

<PAGE>

                                   EXHIBIT B-1

                          FORM OF INITIAL CERTIFICATION

                                                           _____________
                                                               Date

HSBC Bank USA, National Association
425 Fifth Avenue
New York, New York 10018

Structured Asset Securities Corporation
745 Seventh Avenue, 7th Floor
New York, New York 10019

Aurora Loan Services LLC
327 Inverness Drive South
Englewood, Colorado 80112

      Re:   Trust Agreement (the "Trust Agreement"), dated as of February 1,
            2005 among Structured Asset Securities Corporation, as Depositor,
            Aurora Loan Services LLC, as Master Servicer, Wells Fargo Bank,
            National Association, as Securities Administrator and HSBC Bank USA,
            National Association, as Trustee, with respect to Structured
            Adjustable Rate Mortgage Loan Trust Mortgage Pass-Through
            Certificates, Series 2005-4

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 on behalf of the
Trustee, hereby certifies that it (or its custodian) 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], on behalf of
                                         HSBC Bank USA, National Association,
                                         as Trustee

                                         By:________________________________
                                            Name:
                                            Title:

                                     B-1-1
<PAGE>

                                   EXHIBIT B-2

                          FORM OF INTERIM CERTIFICATION
                                                           _____________
                                                               Date

HSBC Bank USA, National Association
425 Fifth Avenue
New York, New York 10018

Structured Asset Securities Corporation
745 Seventh Avenue, 7th Floor
New York, New York 10019

Aurora Loan Services LLC
327 Inverness Drive South
Englewood, Colorado 80112

      Re:   Trust Agreement (the "Trust Agreement"), dated as of February 1,
            2005 among Structured Asset Securities Corporation, as Depositor,
            Aurora Loan Services LLC, as Master Servicer, Wells Fargo Bank,
            National Association, as Securities Administrator and HSBC Bank USA,
            National Association, as Trustee, with respect to Structured
            Adjustable Rate Mortgage Loan Trust Mortgage Pass-Through
            Certificates, Series 2005-4

Ladies and Gentlemen:

      In accordance with Section 2.02(b) 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 (or its custodian) 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 identified above 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

                                     B-2-1
<PAGE>

Trust Agreement including, but not limited to, Section 2.02(b).

                                         [Custodian], on behalf of
                                         HSBC Bank USA, National Association,
                                         as Trustee
                                         By:________________________________
                                            Name:
                                            Title:

                                     B-2-2
<PAGE>

                                   EXHIBIT B-3

                           FORM OF FINAL CERTIFICATION
                                                           _____________
                                                               Date

HSBC Bank USA, National Association
425 Fifth Avenue
New York, New York 10018

Structured Asset Securities Corporation
745 Seventh Avenue, 7th Floor
New York, New York 10019

Aurora Loan Services LLC
327 Inverness Drive South
Englewood, Colorado 80112

      Re:   Trust Agreement (the "Trust Agreement"), dated as of February 1,
            2005 among Structured Asset Securities Corporation, as Depositor,
            Aurora Loan Services LLC, as Master Servicer, Wells Fargo Bank,
            National Association, as Securities Administrator and HSBC Bank USA,
            National Association, as Trustee, with respect to Structured
            Adjustable Rate Mortgage Loan Trust Mortgage Pass-Through
            Certificates, Series 2005-4

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 (or its custodian) 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 above and has determined that each
such document appears to be complete and, based on an examination of such
documents, the information set forth in the 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

                                     B-3-1
<PAGE>

Trust Agreement.

                                           [Custodian], on behalf of
                                           HSBC Bank USA, National Association,
                                           as Trustee

                                           By: ________________________________
                                               Name:
                                               Title:

                                      B-3-2

<PAGE>

                                   EXHIBIT B-4

                               FORM OF ENDORSEMENT

      Pay to the order of HSBC Bank USA, National Association, as trustee (the
"Trustee") under the Trust Agreement dated as of February 1, 2005, among
Structured Asset Securities Corporation, as Depositor, Aurora Loan Services LLC,
as Master Servicer, Wells Fargo Bank, National Association, as Securities
Administrator and the Trustee relating to Structured Adjustable Rate Mortgage
Loan Trust Mortgage Pass-Through Certificates, Series 2005-4, without recourse.

                                           ____________________________________
                                               [current signatory on note]

                                           By: ________________________________
                                               Name:
                                               Title:

                                     B-4-1

<PAGE>

                                    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 February 1, 2005 among
Structured Asset Securities Corporation, as Depositor, Aurora Loan Services LLC,
as Master Servicer, Wells Fargo Bank, National Association, as Securities
Administrator and you, as Trustee (the "Trust Agreement"), the undersigned
Master 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 Master Servicer hereby certifies that all
      amounts received in connection with the loan have been or will be credited
      to the Collection Account or the Certificate Account (whichever is
      applicable) pursuant to the Trust Agreement.)

2.    The Mortgage Loan is being foreclosed.

3.    Mortgage Loan substituted. (The Master 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 Master Servicer hereby certifies that the
      Purchase Price has been credited to the Collection Account or the
      Certificate Account (whichever is applicable) 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

                                      C-1

<PAGE>

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).

         Capitalized terms used herein shall have the meanings ascribed to them
in the Trust Agreement.

                                           ____________________________________
                                             [Name of Master Servicer]

                                           By: ________________________________
                                               Name:
                                               Title: Servicing Officer

                                      C-2

<PAGE>

                                   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:

      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.

1.    That the Purchaser's Taxpayer Identification Number is ______________.

2.    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.

3.    That the Purchaser is not, and on _______________ [date of transfer] will
      not be, an employee benefit plan or arrangement subject to Title I of the
      Employee Retirement Income Security Act of 1974, as amended ("ERISA"), a
      plan subject to Section 4975 of the Internal Revenue Code of 1986, as
      amended (the "Code") or a plan subject to any provisions under any
      federal, state, local, non-U.S. or other laws or regulations that are
      substantively similar to the foregoing provisions of ERISA or the Code
      (collectively, a "Plan"), and is not directly or indirectly acquiring the
      Residual Certificate for, on behalf of or with any assets of any such
      Plan.

                                     D-1-1

<PAGE>

4.    That the Purchaser hereby acknowledges that under the terms of the Trust
      Agreement (the "Agreement") among Structured Asset Securities Corporation,
      HSBC Bank USA, National Association, as Trustee, Wells Fargo Bank,
      National Association, as Securities Administrator and Aurora Loan Services
      LLC, as Master Servicer, dated as of February 1, 2005, no transfer of a
      Residual Certificate shall be permitted to be made to any person unless
      the Depositor and the Trustee have received a certificate from such
      transferee containing the representations in paragraphs 2, 3 and 4 hereof.

5.    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").

6.    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, and that the Purchaser has
      provided financial statements or other financial information requested by
      the transferor in connection with the transfer of the Residual Certificate
      in order to permit the transferor to assess the financial capability of
      the Purchaser to pay such taxes.

7.    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 2, paragraph 5 or paragraph 9 hereof
      are not satisfied or that the Purchaser has reason to believe does not
      satisfy the requirements set forth in paragraph 6 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.

8.    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.

9.    That the Purchaser (i) is a 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-8 ECI
      (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. "Non-U.S. Person" means any person other than (i) a
      citizen or resident of the United States; (ii) a corporation (or entity
      treated as a corporation for tax purposes) created or organized in the
      United States or under the laws of the United States or of any state
      thereof, including, for this purpose, the District of Columbia; (iii) a
      partnership (or entity treated as a partnership for tax purposes)
      organized in the United States or under the laws of the United States or
      of any state thereof, including, for this purpose, the District of
      Columbia (unless provided otherwise by future Treasury regulations); (iv)
      an estate whose income is includible in gross income for United States
      income tax purposes regardless of its source; (v) a trust, if a court
      within the United States is able to exercise

2

<PAGE>

      primary supervision over the administration of the trust and one or more
      U.S. Persons have authority to control all substantial decisions of the
      trust or; (vi) and, to the extent provided in Treasury regulations,
      certain trusts in existence prior to August 20, 1996 that are treated as
      United States persons prior to such date and elect to continue to be
      treated as United States persons.

10.   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 6 and paragraph 9 hereof.

11.   That the Purchaser consents to the designation of the Securities
      Administrator as its agent to act as "tax matters person" of the Trust
      Fund pursuant to the Trust Agreement.

      Terms used in this transfer affidavit which are not otherwise defined
herein have the respective meanings assigned thereto in the Trust Agreement.

3

<PAGE>

      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 ________________________

STATE OF _________________________

My commission expires the ____ day of ______, 20__.

4

<PAGE>

                                  EXHIBIT D-2

          FORM OF RESIDUAL CERTIFICATE TRANSFER AFFIDAVIT (TRANSFEROR)

                                                                 ______________
                                                                      Date

      Re:   Structured Adjustable Rate Mortgage Loan Trust Mortgage Pass-Through
            Certificates, Series 2005-4

      _______________________ (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 6 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

<PAGE>

                                    EXHIBIT E

                               SERVICING AGREEMENT

                               [See Exhibit 99.2]

                                      E-1

<PAGE>

                                    EXHIBIT F

                     FORM OF RULE 144A TRANSFER CERTIFICATE

      Re:   Structured Adjustable Rate Mortgage Loan Trust Mortgage Pass-Through
            Certificates, Series 2005-4

      Reference is hereby made to the Trust Agreement (the "Trust Agreement"),
dated as of February 1, 2005 among Structured Asset Securities Corporation, as
Depositor, Aurora Loan Services LLC, as Master Servicer Wells Fargo Bank,
National Association, as Securities Administrator and HSBC Bank USA, National
Association, 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 Principal Amount 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 the
benefit of the Trustee, the Securities Administrator, the Placement Agent and
the Depositor.

                                            ____________________________________
                                               [Name of Transferor]

                                            By: ________________________________
                                                Name:
                                                Title:

Dated: __________________, ________

                                      F-1

<PAGE>

                                    EXHIBIT G

                         FORM OF PURCHASER'S LETTER FOR
                        INSTITUTIONAL ACCREDITED INVESTOR

                                                                ________________
                                                                      Date

Dear Sirs:

      In connection with our proposed purchase of $______________ principal
amount of Structured Adjustable Rate Mortgage Loan Trust Mortgage Pass-Through
Certificates, Series 2005-4 (the "Privately Offered Certificates") of Structured
Asset Securities Corporation (the "Depositor") which are held in the form of
Definitive Certificates, 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 (which includes the Placement
      Agent) 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 (the "Trust Agreement"), dated as of
      February 1, 2005 among Structured Asset Securities Corporation, as
      Depositor, Aurora Loan Services LLC, as Master Servicer, Wells Fargo Bank,
      National Association, as Securities Administrator and HSBC Bank USA,
      National Association, as 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.

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, the Certificate Registrar 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.

                                      G-1

<PAGE>

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 an ERISA-Restricted Certificate, we are not a Plan and
      we are not acquiring the ERISA-Restricted Certificate for, on behalf of or
      with any assets of a Plan, except as may be permitted pursuant to 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.

      You and the Depositor, the Securities Administrator and the Trustee 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-2

<PAGE>

                                    EXHIBIT H

                       [FORM OF ERISA TRANSFER AFFIDAVIT]

STATE OF NEW YORK                   )
                                    )  ss.:
COUNTY OF NEW YORK                  )

      The undersigned, being first duly sworn, deposes and says as follows:

7.    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.

8.    The Investor (A) is not, and on _______________ [date of transfer] will
      not be, an employee benefit plan or arrangement subject to Title I of the
      Employee Retirement Income Security Act of 1974, as amended ("ERISA"), a
      plan subject to Section 4975 of the Internal Revenue Code of 1986, as
      amended (the "Code") or a plan subject to any provisions under any
      federal, state, local, non-U.S. or other laws or regulations that are
      substantively similar to the foregoing provisions of ERISA or the Code
      ("Similar Law") (collectively, a "Plan"), and is not directly or
      indirectly acquiring the Certificate for, on behalf of or with any assets
      of any such Plan, (B) if the Certificate has been the subject of an
      ERISA-Qualifying Underwriting, is an insurance company that is acquiring
      the Certificate with assets of an "insurance company general account" as
      defined in Section V(E) of Prohibited Transaction Class Exemption ("PTCE")
      95-60 and the acquisition and holding of the Certificate are covered and
      exempt under Sections I and III of PTCE 95-60, or (C) solely in the case
      of a Definitive Certificate, shall herewith deliver an Opinion of Counsel
      satisfactory to the Certificate Registrar, the Trustee and the Depositor,
      and upon which the Trustee, the Certificate Registrar and the Depositor
      shall be entitled to rely, to the effect that the acquisition and holding
      of such Certificate by the Investor will not result in a nonexempt
      prohibited transaction under Title I of ERISA or Section 4975 of the Code,
      or a violation of Similar Law, and will not subject the Trustee, the
      Master Servicer, the Securities Administrator, the Certificate Registrar,
      any 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 Trustee, the Master Servicer, the
      Securities Administrator, the Certificate Registrar, any Servicer or the
      Depositor.

9.    The Investor hereby acknowledges that under the terms of the Trust
      Agreement (the "Agreement") among Structured Asset Securities Corporation,
      as Depositor, Aurora Loan Services LLC, as Master Servicer, Wells Fargo
      Bank, National Association and HSBC Bank USA, National Association, as
      Trustee, dated as of February 1, 2005, no transfer of the ERISA-Restricted
      Certificates (other than the Class R Certificate) shall be permitted to be
      made to any person unless the Depositor, the Certificate Registrar and
      Trustee have received an affidavit from such transferee in the form hereof
      or an opinion of counsel as provided herein.

                                      H-1

<PAGE>

10.   Capitalized terms used but not defined herein shall have the meanings
      given to such terms in the Trust Agreement.

2

<PAGE>

      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__.

3

<PAGE>

                                    EXHIBIT I

                            MONTHLY REMITTANCE ADVICE

                             [INTENTIONALLY OMITTED]

                                      I-1

<PAGE>

                                    EXHIBIT J

                      MONTHLY ELECTRONIC DATA TRANSMISSION

                             [INTENTIONALLY OMITTED]

                                      J-1

<PAGE>

                                    EXHIBIT K

                              CUSTODIAL AGREEMENTS

                             [Intentionally Omitted]

                                      K-1

<PAGE>

                                   EXHIBIT L-1

                          FORM OF TRANSFER CERTIFICATE
                  FOR TRANSFER FROM RESTRICTED GLOBAL SECURITY
                         TO REGULATIONS GLOBAL SECURITY
                      (Transfers pursuant to Section 3.03(h)(B)
                                of the Agreement)

            Re:   Structured Adjustable Rate Mortgage Loan Trust Mortgage Loan
                  Trust Mortgage Pass-Through Certificates, Series 2005-4

      Reference is hereby made to the Trust Agreement (the "Agreement") among
Structured Asset Securities Corporation, as Depositor, Aurora Loan Services LLC,
as Master Servicer, Wells Fargo Bank, National Association and HSBC Bank USA,
National Association, as Trustee, dated as of February 1, 2005. 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).

      The Depositor, the Securities Administrator and the Trustee 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]

                                     L-1-1

<PAGE>

                                          By:
                                              Name:
                                              Title:

Date: __________, ____

                                     L-1-2

<PAGE>

                                   EXHIBIT L-2

                    FORM OF TRANSFER CERTIFICATE FOR TRANSFER
                        FROM REGULATIONS GLOBAL SECURITY
                          TO RESTRICTED GLOBAL SECURITY
                   (Transfers pursuant to Section 3.03(h)(C)
                                of the Agreement)

            Re:   Structured Adjustable Rate Mortgage Loan Trust Mortgage
                  Pass-Through Certificates, Series 2005-4

      Reference is hereby made to the Trust Agreement (the "Agreement") among
Structured Asset Securities Corporation, as Depositor, Aurora Loan Services LLC,
as Master Servicer, Wells Fargo Bank, National Association and HSBC Bank USA,
National Association, as Trustee, dated as of February 1, 2005. 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: _______________, ___

                                     L-2-1

<PAGE>

                                    EXHIBIT M

                     FORM OF CERTIFICATION TO BE PROVIDED TO
             THE DEPOSITOR AND THE MASTER SERVICER BY THE SECURITIES
                                  ADMINISTRATOR

Structured Asset Securities Corporation
745 7th Avenue, 7th Floor
New York, New York 10019

Aurora Loan Services LLC
327 Inverness Drive South
Englewood, Colorado 80112

Re:      Structured Adjustable Rate Mortgage Loan Trust,
         Mortgage Pass-Through Certificates, Series 2005-4

I, [[Identify the certifying individual]], a [[title]] of Wells Fargo Bank,
National Association, as Securities Administrator, hereby certify to Aurora Loan
Services, Inc., as master servicer (the "Master Servicer"), and its officers,
directors and affiliates, and with the knowledge and intent that they will rely
upon this certification, that:

(i)      I have reviewed the annual report on Form 10-K for the fiscal year
         [[ ]], and all reports on Form 8-K 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 on my knowledge, the information in these distribution reports
         prepared by the Securities Administrator, taken as a whole, does not
         contain any untrue statement of a material fact or omit to state
         material fact necessary to make the statements made, in light of the
         circumstances under which such statements were made, not misleading as
         of the last day of the period covered by that annual report; and

(iii)    Based on my knowledge, the distribution information required to be
         provided by Securities Administrator under the Trust Agreement is
         included in these reports.

Date:

                                      Wells Fargo Bank, National Association, as
                                      Securities Administrator

                                      By:      ____________________________
                                      Name:    ____________________________
                                      Title:   ____________________________

                                      M-1

<PAGE>

                                   SCHEDULE A

                             MORTGAGE LOAN SCHEDULE

                             [Intentionally Omitted]

                                    Sch. A-1

<PAGE>

                                   SCHEDULE B

                        POOL 3 AX MORTGAGE LOAN SCHEDULE

                             [Intentionally Omitted]

                                    Sch. B-1

<PAGE>

                                   SCHEDULE C

                        POOL 3 PAX MORTGAGE LOAN SCHEDULE

                             [Intentionally Omitted]

                                    Sch. A-2

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