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                                                                    EXHIBIT 10.2

                            STRUCTURAL GENOMIX, INC.

                        2000 EQUITY INCENTIVE PLAN
                                (AS AMENDED)

                      INITIALLY ADOPTED FEBRUARY 18, 2000
               INITIALLY APPROVED BY STOCKHOLDERS MARCH 29, 2000


                      TERMINATION DATE: FEBRUARY 17, 2010


1.    PURPOSES.

      (a) ELIGIBLE STOCK AWARD RECIPIENTS. The persons eligible to receive Stock
Awards are the Employees, Directors and Consultants of the Company and its
Affiliates.

      (b) AVAILABLE STOCK AWARDS. The purpose of the Plan is to provide a means
by which eligible recipients of Stock Awards may be given an opportunity to
benefit from increases in value of the Common Stock through the granting of the
following Stock Awards: (i) Incentive Stock Options, (ii) Nonstatutory Stock
Options, (iii) stock bonuses and (iv) rights to acquire restricted stock.

      (c) GENERAL PURPOSE. The Company, by means of the Plan, seeks to retain
the services of the group of persons eligible to receive Stock Awards, to secure
and retain the services of new members of this group and to provide incentives
for such persons to exert maximum efforts for the success of the Company and its
Affiliates.


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2.    DEFINITIONS.

      (a) "AFFILIATE" means any parent corporation or subsidiary corporation of
the Company, whether now or hereafter existing, as those terms are defined in
Sections 424(e) and (f), respectively, of the Code.

      (b) "BOARD" means the Board of Directors of the Company.

      (c) "CODE" means the Internal Revenue Code of 1986, as amended.

      (d) "COMMITTEE" means a committee of one or more members of the Board
appointed by the Board in accordance with subsection 3(c).

      (e) "COMMON STOCK" means the common stock of the Company.

      (f) "COMPANY" means Structural GenomiX, Inc., a Delaware corporation.

      (g) "CONSULTANT" means any person, including an advisor, (i) engaged by
the Company or an Affiliate to render consulting or advisory services and who is
compensated for such services or (ii) who is a member of the Board of Directors
of an Affiliate. However, the term "Consultant" shall not include either
Directors who are not compensated by the Company for their services as Directors
or Directors who are merely paid a director's fee by the Company for their
services as Directors.

      (h) "CONTINUOUS SERVICE" means that the Participant's service with the
Company or an Affiliate, whether as an Employee, Director or Consultant, is not
interrupted or terminated. The Participant's Continuous Service shall not be
deemed to have terminated merely because of a change in the capacity in which
the Participant renders service to the Company or an Affiliate as an Employee,
Consultant or Director or a change in the entity for which the Participant
renders such service, provided that there is no interruption or termination of
the Participant's Continuous Service. For example, a change in status from an
Employee of the Company to a Consultant of an Affiliate or a Director will not
constitute an interruption of Continuous Service. The Board or the chief
executive officer of the Company, in that party's sole discretion, may determine
whether Continuous Service shall be considered interrupted in the case of any
leave of absence approved by that party, including sick leave, military leave or
any other personal leave.

      (i) "COVERED EMPLOYEE" means the chief executive officer and the four (4)
other highest compensated officers of the Company for whom total compensation is
required to be reported to stockholders under the Exchange Act, as determined
for purposes of Section 162(m) of the Code.

      (j) "DIRECTOR" means a member of the Board of Directors of the Company.

      (k) "DISABILITY" means (i) before the Listing Date, the inability of a
person, in the opinion of a qualified physician acceptable to the Company, to
perform the major duties of that


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person's position with the Company or an Affiliate of the Company because of the
sickness or injury of the person.

      (l) "EMPLOYEE" means any person employed by the Company or an Affiliate.
Mere service as a Director or payment of a director's fee by the Company or an
Affiliate shall not be sufficient to constitute "employment" by the Company or
an Affiliate.

      (m) "EXCHANGE ACT" means the Securities Exchange Act of 1934, as amended.

      (n) "FAIR MARKET VALUE" means, as of any date, the value of the Common
Stock determined as follows:

            (i) If the Common Stock is listed on any established stock exchange
or traded on the NASDAQ National Market or the NASDAQ SmallCap Market, the Fair
Market Value of a share of Common Stock shall be the closing sales price for
such stock (or the closing bid, if no sales were reported) as quoted on such
exchange or market (or the exchange or market with the greatest volume of
trading in the Common Stock) on the last market trading day prior to the day of
determination, as reported in The Wall Street Journal or such other source as
the Board deems reliable.

            (ii) In the absence of such markets for the Common Stock, the Fair
Market Value shall be determined in good faith by the Board.

            (iii) Prior to the Listing Date, the value of the Common Stock shall
be determined in a manner consistent with Section 260.140.50 of Title 10 of the
California Code of Regulations.

      (o) "INCENTIVE STOCK OPTION" means an Option intended to qualify as an
incentive stock option within the meaning of Section 422 of the Code and the
regulations promulgated thereunder.

      (p) "LISTING DATE" means the first date upon which any security of the
Company is listed (or approved for listing) upon notice of issuance on any
securities exchange or designated (or approved for designation) upon notice of
issuance as a national market security on an interdealer quotation system if
such securities exchange or interdealer quotation system has been certified in
accordance with the provisions of Section 25100(o) of the California Corporate
Securities Law of 1968.

      (q) "NON-EMPLOYEE DIRECTOR" means a Director who either (i) is not a
current Employee or Officer of the Company or its parent or a subsidiary, does
not receive compensation (directly or indirectly) from the Company or its parent
or a subsidiary for services rendered as a Consultant or in any capacity other
than as a Director (except for an amount as to which disclosure would not be
required under Item 404(a) of Regulation S-K promulgated pursuant to the
Securities Act ("Regulation S-K")), does not possess an interest in any other
transaction as to which disclosure would be required under Item 404(a) of
Regulation S-K and is not engaged in a


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business relationship as to which disclosure would be required under Item 404(b)
of Regulation S-K; or (ii) is otherwise considered a "non-employee director" for
purposes of Rule 16b-3.

      (r) "NONSTATUTORY STOCK OPTION" means an Option not intended to qualify as
an Incentive Stock Option.

      (s) "OFFICER" means (i) before the Listing Date, any person designated by
the Company as an officer and (ii) on and after the Listing Date, a person who
is an officer of the Company within the meaning of Section 16 of the Exchange
Act and the rules and regulations promulgated thereunder.

      (t) "OPTION" means an Incentive Stock Option or a Nonstatutory Stock
Option granted pursuant to the Plan.

      (u) "OPTION AGREEMENT" means a written agreement between the Company and
an Optionholder evidencing the terms and conditions of an individual Option
grant. Each Option Agreement shall be subject to the terms and conditions of the
Plan.

      (v) "OPTIONHOLDER" means a person to whom an Option is granted pursuant to
the Plan or, if applicable, such other person who holds an outstanding Option.

      (w) "OUTSIDE DIRECTOR" means a Director who either (i) is not a current
employee of the Company or an "affiliated corporation" (within the meaning of
Treasury Regulations promulgated under Section 162(m) of the Code), is not a
former employee of the Company or an "affiliated corporation" receiving
compensation for prior services (other than benefits under a tax qualified
pension plan), was not an officer of the Company or an "affiliated corporation"
at any time and is not currently receiving direct or indirect remuneration from
the Company or an "affiliated corporation" for services in any capacity other
than as a Director or (ii) is otherwise considered an "outside director" for
purposes of Section 162(m) of the Code.

      (x) "PARTICIPANT" means a person to whom a Stock Award is granted pursuant
to the Plan or, if applicable, such other person who holds an outstanding Stock
Award.

      (y) "PLAN" means this Structural GenomiX, Inc. 2000 Equity Incentive Plan.

      (z) "RULE 16B-3" means Rule 16b-3 promulgated under the Exchange Act or
any successor to Rule 16b-3, as in effect from time to time.

      (aa) "SECURITIES ACT" means the Securities Act of 1933, as amended.

      (bb) "STOCK AWARD" means any right granted under the Plan, including an
Option, a stock bonus and a right to acquire restricted stock.

      (cc) "STOCK AWARD AGREEMENT" means a written agreement between the Company
and a holder of a Stock Award evidencing the terms and conditions of an
individual Stock Award grant. Each Stock Award Agreement shall be subject to the
terms and conditions of the Plan.


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      (dd) "TEN PERCENT STOCKHOLDER" means a person who owns (or is deemed to
own pursuant to Section 424(d) of the Code) stock possessing more than ten
percent (10%) of the total combined voting power of all classes of stock of the
Company or of any of its Affiliates.

3.    ADMINISTRATION.

      (a) ADMINISTRATION BY BOARD. The Board shall administer the Plan unless
and until the Board delegates administration to a Committee, as provided in
subsection 3(c).

      (b) POWERS OF BOARD. The Board shall have the power, subject to, and
within the limitations of, the express provisions of the Plan:

            (i) To determine from time to time which of the persons eligible
under the Plan shall be granted Stock Awards; when and how each Stock Award
shall be granted; what type or combination of types of Stock Award shall be
granted; the provisions of each Stock Award granted (which need not be
identical), including the time or times when a person shall be permitted to
receive Common Stock pursuant to a Stock Award; and the number of shares of
Common Stock with respect to which a Stock Award shall be granted to each such
person.

            (ii) To construe and interpret the Plan and Stock Awards granted
under it, and to establish, amend and revoke rules and regulations for its
administration. The Board, in the exercise of this power, may correct any
defect, omission or inconsistency in the Plan or in any Stock Award Agreement,
in a manner and to the extent it shall deem necessary or expedient to make the
Plan fully effective.

            (iii) To amend the Plan or a Stock Award as provided in Section 12.

            (iv) Generally, to exercise such powers and to perform such acts as
the Board deems necessary or expedient to promote the best interests of the
Company which are not in conflict with the provisions of the Plan.

      (C) DELEGATION TO COMMITTEE.

            (i) GENERAL. The Board may delegate administration of the Plan to a
Committee or Committees of one (1) or more members of the Board, and the term
"Committee" shall apply to any person or persons to whom such authority has been
delegated. If administration is delegated to a Committee, the Committee shall
have, in connection with the administration of the Plan, the powers theretofore
possessed by the Board, including the power to delegate to a subcommittee any of
the administrative powers the Committee is authorized to exercise (and
references in this Plan to the Board shall thereafter be to the Committee or
subcommittee), subject, however, to such resolutions, not inconsistent with the
provisions of the Plan, as may be adopted from time to time by the Board. The
Board may abolish the Committee at any time and revest in the Board the
administration of the Plan.

            (ii) COMMITTEE COMPOSITION WHEN COMMON STOCK IS PUBLICLY TRADED. At
such time as the Common Stock is publicly traded, in the discretion of the
Board, a Committee


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may consist solely of two or more Outside Directors, in accordance with Section
162(m) of the Code, and/or solely of two or more Non-Employee Directors, in
accordance with Rule 16b-3. Within the scope of such authority, the Board or the
Committee may (1) delegate to a committee of one or more members of the Board
who are not Outside Directors the authority to grant Stock Awards to eligible
persons who are either (a) not then Covered Employees and are not expected to be
Covered Employees at the time of recognition of income resulting from such Stock
Award or (b) not persons with respect to whom the Company wishes to comply with
Section 162(m) of the Code and/or (2) delegate to a committee of one or more
members of the Board who are not Non-Employee Directors the authority to grant
Stock Awards to eligible persons who are not then subject to Section 16 of the
Exchange Act.

      (d) EFFECT OF BOARD'S DECISION. All determinations, interpretations and
constructions made by the Board in good faith shall not be subject to review by
any person and shall be final, binding and conclusive on all persons.

4.    SHARES SUBJECT TO THE PLAN.


      (a) SHARE RESERVE. Subject to the provisions of Section 11 relating to
adjustments upon changes in Common Stock, the Common Stock that may be issued
pursuant to Stock Awards shall not exceed in the aggregate One Million Seven
Hundred Fifty-Five Thousand (1,755,000) shares of Common Stock.


      (b) REVERSION OF SHARES TO THE SHARE RESERVE. If any Option shall for any
reason expire or otherwise terminate, in whole or in part, without having been
exercised in full, the shares of Common Stock not acquired under such Option
shall revert to and again become available for issuance under the Plan. In
addition, if any shares of Common Stock issued under the Plan shall for any
reason be repurchased or reacquired by the Company because they have not vested
under the terms of the Stock Award Agreement governing such shares, then any and
all shares of Common Stock so repurchased or reacquired shall revert to and
again become available for issuance under the Plan for Stock Awards other than
Incentive Stock Options.

      (c) SOURCE OF SHARES. The shares of Common Stock subject to the Plan may
be unissued shares or reacquired shares, bought on the market or otherwise.

      (d) SHARE RESERVE LIMITATION. Prior to the Listing Date and to the extent
then required by Section 260.140.45 of Title 10 of the California Code of
Regulations, the total number of shares of Common Stock issuable upon exercise
of all outstanding Options and the total number of shares of Common Stock
provided for under any stock bonus or similar plan of the Company shall not
exceed the applicable percentage as calculated in accordance with the conditions
and exclusions of Section 260.140.45 of Title 10 of the California Code of
Regulations, based on the shares of Common Stock of the Company that are
outstanding at the time the calculation is made (generally thirty percent (30%)
of the then outstanding shares of the issuer, unless a higher percentage is
approved by at least two-thirds of the outstanding shares entitled to vote).


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5.    ELIGIBILITY.

      (a) ELIGIBILITY FOR SPECIFIC STOCK AWARDS. Incentive Stock Options may be
granted only to Employees. Stock Awards other than Incentive Stock Options may
be granted to Employees, Directors and Consultants.

      (b) TEN PERCENT STOCKHOLDERS.

            (i) A Ten Percent Stockholder shall not be granted an Incentive
Stock Option unless the exercise price of such Option is at least one hundred
ten percent (110%) of the Fair Market Value of the Common Stock at the date of
grant and the Option is not exercisable after the expiration of five (5) years
from the date of grant.

            (ii) Prior to the Listing Date, a Ten Percent Stockholder shall not
be granted a Nonstatutory Stock Option unless the exercise price of such Option
is at least (i) one hundred ten percent (110%) of the Fair Market Value of the
Common Stock at the date of grant or (ii) such lower percentage of the Fair
Market Value of the Common Stock at the date of grant as is permitted by Section
260.140.41 of Title 10 of the California Code of Regulations at the time of the
grant of the Option.

            (iii) Prior to the Listing Date, a Ten Percent Stockholder shall not
be granted a restricted stock purchase award unless the purchase price of the
restricted stock is at least (i) one hundred percent (100%) of the Fair Market
Value of the Common Stock at the date of grant or (ii) such lower percentage of
the Fair Market Value of the Common Stock at the date of grant as is permitted
by Section 260.140.41 of Title 10 of the California Code of Regulations at the
time of the grant of the restricted stock purchase award.


      (c) SECTION 162(m) LIMITATION. Subject to the provisions of Section 11
relating to adjustments upon changes in the shares of Common Stock, no Employee
shall be eligible to be granted Options covering more than three hundred
thousand (300,000) shares of Common Stock during any calendar year. This
subsection 5(c) shall not apply prior to the Listing Date and, following the
Listing Date, this subsection 5(c) shall not apply until (i) the earliest of:
(1) the first material modification of the Plan (including any increase in the
number of shares of Common Stock reserved for issuance under the Plan in
accordance with Section 4); (2) the issuance of all of the shares of Common
Stock reserved for issuance under the Plan; (3) the expiration of the Plan; or
(4) the first meeting of stockholders at which Directors are to be elected that
occurs after the close of the third calendar year following the calendar year in
which occurred the first registration of an equity security under Section 12 of
the Exchange Act; or (ii) such other date required by Section 162(m) of the Code
and the rules and regulations promulgated thereunder.


      (d) CONSULTANTS.

            (i) Prior to the Listing Date, a Consultant shall not be eligible
for the grant of a Stock Award if, at the time of grant, either the offer or the
sale of the Company's securities to such Consultant is not exempt under Rule 701
of the Securities Act ("Rule 701") because of the


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nature of the services that the Consultant is providing to the Company, or
because the Consultant is not a natural person, or as otherwise provided by Rule
701, unless the Company determines that such grant need not comply with the
requirements of Rule 701 and will satisfy another exemption under the Securities
Act as well as comply with the securities laws of all other relevant
jurisdictions.

            (ii) From and after the Listing Date, a Consultant shall not be
eligible for the grant of a Stock Award if, at the time of grant, a Form S-8
Registration Statement under the Securities Act ("Form S-8") is not available to
register either the offer or the sale of the Company's securities to such
Consultant because of the nature of the services that the Consultant is
providing to the Company, or because the Consultant is not a natural person, or
as otherwise provided by the rules governing the use of Form S-8, unless the
Company determines both (i) that such grant (A) shall be registered in another
manner under the Securities Act (e.g., on a Form S-3 Registration Statement) or
(B) does not require registration under the Securities Act in order to comply
with the requirements of the Securities Act, if applicable, and (ii) that such
grant complies with the securities laws of all other relevant jurisdictions.

            (iii) Rule 701 and Form S-8 generally are available to consultants
and advisors only if (i) they are natural persons; (ii) they provide bona fide
services to the issuer, its parents, its majority-owned subsidiaries or
majority-owned subsidiaries of the issuer's parent; and (iii) the services are
not in connection with the offer or sale of securities in a capital-raising
transaction, and do not directly or indirectly promote or maintain a market for
the issuer's securities.

6.    OPTION PROVISIONS.

      Each Option shall be in such form and shall contain such terms and
conditions as the Board shall deem appropriate. All Options shall be separately
designated Incentive Stock Options or Nonstatutory Stock Options at the time of
grant, and, if certificates are issued, a separate certificate or certificates
will be issued for shares of Common Stock purchased on exercise of each type of
Option. The provisions of separate Options need not be identical, but each
Option shall include (through incorporation of provisions hereof by reference in
the Option or otherwise) the substance of each of the following provisions:

      (a) TERM. Subject to the provisions of subsection 5(b) regarding Ten
Percent Stockholders, no Option granted prior to the Listing Date shall be
exercisable after the expiration of ten (10) years from the date it was granted,
and no Incentive Stock Option granted on or after the Listing Date shall be
exercisable after the expiration of ten (10) years from the date it was granted.

      (b) EXERCISE PRICE OF AN INCENTIVE STOCK OPTION. Subject to the provisions
of subsection 5(b) regarding Ten Percent Stockholders, the exercise price of
each Incentive Stock Option shall be not less than one hundred percent (100%) of
the Fair Market Value of the Common Stock subject to the Option on the date the
Option is granted. Notwithstanding the foregoing, an Incentive Stock Option may
be granted with an exercise price lower than that set forth in the preceding
sentence if such Option is granted pursuant to an assumption or


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substitution for another option in a manner satisfying the provisions of Section
424(a) of the Code.

      (c) EXERCISE PRICE OF A NONSTATUTORY STOCK OPTION. Subject to the
provisions of subsection 5(b) regarding Ten Percent Stockholders, the exercise
price of each Nonstatutory Stock Option granted prior to the Listing Date shall
be not less than eighty-five percent (85%) of the Fair Market Value of the
Common Stock subject to the Option on the date the Option is granted. The
exercise price of each Nonstatutory Stock Option granted on or after the Listing
Date shall be determined by the Board. Notwithstanding the foregoing, a
Nonstatutory Stock Option may be granted with an exercise price lower than that
set forth in the preceding sentence if such Option is granted pursuant to an
assumption or substitution for another option in a manner satisfying the
provisions of Section 424(a) of the Code.

(d) CONSIDERATION. The purchase price of Common Stock acquired pursuant to an
Option shall be paid, to the extent permitted by applicable statutes and
regulations, either (i) in cash at the time the Option is exercised or (ii) at
the discretion of the Board at the time of the grant of the Option (or
subsequently in the case of a Nonstatutory Stock Option) (1) by delivery to the
Company of other Common Stock, (2) according to a deferred payment or other
similar arrangement with the Optionholder, or (3) in any other form of legal
consideration that may be acceptable to the Board. Unless otherwise specifically
provided in the Option, the purchase price of Common Stock acquired pursuant to
an Option that is paid by delivery to the Company of other Common Stock
acquired, directly or indirectly from the Company, shall be paid only by shares
of the Common Stock of the Company that have been held for more than six (6)
months (or such longer or shorter period of time required to avoid a charge to
earnings for financial accounting purposes). At any time that the Company is
incorporated in Delaware, payment of the Common Stock's "par value," as defined
in the Delaware General Corporation Law, shall not be made by deferred payment.

      In the case of any deferred payment arrangement, interest shall be
compounded at least annually and shall be charged at the minimum rate of
interest necessary to avoid the treatment as interest, under any applicable
provisions of the Code, of any amounts other than amounts stated to be interest
under the deferred payment arrangement.

      (e) TRANSFERABILITY OF AN INCENTIVE STOCK OPTION. An Incentive Stock
Option shall not be transferable except by will or by the laws of descent and
distribution and shall be exercisable during the lifetime of the Optionholder
only by the Optionholder. Notwithstanding the foregoing, the Optionholder may,
by delivering written notice to the Company, in a form satisfactory to the
Company, designate a third party who, in the event of the death of the
Optionholder, shall thereafter be entitled to exercise the Option.

      (f) TRANSFERABILITY OF A NONSTATUTORY STOCK OPTION. A Nonstatutory Stock
Option granted prior to the Listing Date shall not be transferable except by
will or by the laws of descent and distribution and, to the extent provided in
the Option Agreement, to such further extent as permitted by Section
260.140.41(d) of Title 10 of the California Code of Regulations at the time of
the grant of the Option, and shall be exercisable during the lifetime of the
Optionholder only by the Optionholder or, if applicable, a permitted transferee.
A Nonstatutory Stock Option


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granted on or after the Listing Date shall be transferable to the extent
provided in the Option Agreement. If the Nonstatutory Stock Option does not
provide for transferability, then the Nonstatutory Stock Option shall not be
transferable except by will or by the laws of descent and distribution and shall
be exercisable during the lifetime of the Optionholder only by the Optionholder.
Notwithstanding the foregoing, the Optionholder may, by delivering written
notice to the Company, in a form satisfactory to the Company, designate a third
party who, in the event of the death of the Optionholder, shall thereafter be
entitled to exercise the Option.

      (g) VESTING GENERALLY. The total number of shares of Common Stock subject
to an Option may, but need not, vest and therefore become exercisable in
periodic installments that may, but need not, be equal. The Option may be
subject to such other terms and conditions on the time or times when it may be
exercised (which may be based on performance or other criteria) as the Board may
deem appropriate. The vesting provisions of individual Options may vary. The
provisions of this subsection 6(g) are subject to any Option provisions
governing the minimum number of shares of Common Stock as to which an Option may
be exercised.

      (h) MINIMUM VESTING PRIOR TO THE LISTING DATE. Notwithstanding the
foregoing subsection 6(g), to the extent that the following restrictions on
vesting are required by Section 260.140.41(f) of Title 10 of the California Code
of Regulations at the time of the grant of the Option, then:

            (i) Options granted prior to the Listing Date to an Employee who is
not an Officer, Director or Consultant shall provide for vesting of the total
number of shares of Common Stock at a rate of at least twenty percent (20%) per
year over five (5) years from the date the Option was granted, subject to
reasonable conditions such as continued employment; and

            (ii) Options granted prior to the Listing Date to Officers,
Directors or Consultants may be made exercisable, subject to conditions such as
continued employment or performance criteria, at any time or during any period
established by the Company.

      (i) TERMINATION OF CONTINUOUS SERVICE. In the event an Optionholder's
Continuous Service terminates (other than upon the Optionholder's death or
Disability), the Optionholder may exercise his or her Option (to the extent that
the Optionholder was entitled to exercise such Option as of the date of
termination) but only within such period of time ending on the earlier of (i)
the date three (3) months following the termination of the Optionholder's
Continuous Service (or such longer or shorter period specified in the Option
Agreement, which period shall not be less than thirty (30) days for Options
granted prior to the Listing Date unless such termination is for "cause," as
defined in the Optionholder's Option Agreement), or (ii) the expiration of the
term of the Option as set forth in the Option Agreement. If, after termination,
the Optionholder does not exercise his or her Option within the time specified
in the Option Agreement, the Option shall terminate.

      (j) EXTENSION OF TERMINATION DATE. An Optionholder's Option Agreement may
also provide that if the exercise of the Option following the termination of the
Optionholder's Continuous Service (other than upon the Optionholder's death or
Disability) would be prohibited


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at any time solely because the issuance of shares of Common Stock would violate
the registration requirements under the Securities Act or other applicable
securities law, then the Option shall terminate on the earlier of (i) the
expiration of the term of the Option set forth in subsection 6(a) or (ii) the
expiration of a period of three (3) months after the termination of the
Optionholder's Continuous Service during which the exercise of the Option would
not be in violation of such registration requirements.

      (k) DISABILITY OF OPTIONHOLDER. In the event that an Optionholder's
Continuous Service terminates as a result of the Optionholder's Disability, the
Optionholder may exercise his or her Option (to the extent that the Optionholder
was entitled to exercise such Option as of the date of termination), but only
within such period of time ending on the earlier of (i) the date twelve (12)
months following such termination (or such longer or shorter period specified in
the Option Agreement, which period shall not be less than six (6) months for
Options granted prior to the Listing Date) or (ii) the expiration of the term of
the Option as set forth in the Option Agreement. If, after termination, the
Optionholder does not exercise his or her Option within the time specified
herein, the Option shall terminate.

      (l) DEATH OF OPTIONHOLDER. In the event (i) an Optionholder's Continuous
Service terminates as a result of the Optionholder's death or (ii) the
Optionholder dies within the period (if any) specified in the Option Agreement
after the termination of the Optionholder's Continuous Service for a reason
other than death, then the Option may be exercised (to the extent the
Optionholder was entitled to exercise such Option as of the date of death) by
the Optionholder's estate, by a person who acquired the right to exercise the
Option by bequest or inheritance or by a person designated to exercise the
Option upon the Optionholder's death pursuant to subsection 6(e) or 6(f), but
only within the period ending on the earlier of (1) the date eighteen (18)
months following the date of death (or such longer or shorter period specified
in the Option Agreement, which period shall not be less than six (6) months for
Options granted prior to the Listing Date) or (2) the expiration of the term of
such Option as set forth in the Option Agreement. If, after death, the Option is
not exercised within the time specified herein, the Option shall terminate.

      (m) EARLY EXERCISE. The Option may, but need not, include a provision
whereby the Optionholder may elect at any time before the Optionholder's
Continuous Service terminates to exercise the Option as to any part or all of
the shares of Common Stock subject to the Option prior to the full vesting of
the Option. Subject to the "Repurchase Limitation" in subsection 10(h), any
unvested shares of Common Stock so purchased may be subject to a repurchase
option in favor of the Company or to any other restriction the Board determines
to be appropriate.

      (n) RIGHT OF REPURCHASE. Subject to the "Repurchase Limitation" in
subsection 10(h), the Option may, but need not, include a provision whereby the
Company may elect, prior to the Listing Date, to repurchase all or any part of
the vested shares of Common Stock acquired by the Optionholder pursuant to the
exercise of the Option.

      (o) RIGHT OF FIRST REFUSAL. The Option may, but need not, include a
provision whereby the Company may elect, prior to the Listing Date, to exercise
a right of first refusal


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<PAGE>
following receipt of notice from the Optionholder of the intent to transfer all
or any part of the shares of Common Stock received upon the exercise of the
Option.

      (p) RE-LOAD OPTIONS.

            (i) Without in any way limiting the authority of the Board to make
or not to make grants of Options hereunder, the Board shall have the authority
(but not an obligation) to include as part of any Option Agreement a provision
entitling the Optionholder to a further Option (a "Re-Load Option") in the event
the Optionholder exercises the Option evidenced by the Option Agreement, in
whole or in part, by surrendering other shares of Common Stock in accordance
with this Plan and the terms and conditions of the Option Agreement. Unless
otherwise specifically provided in the Option, the Optionholder shall not
surrender shares of Common Stock acquired, directly or indirectly from the
Company, unless such shares have been held for more than six (6) months (or such
longer or shorter period of time required to avoid a charge to earnings for
financial accounting purposes).

            (ii) Any such Re-Load Option shall (1) provide for a number of
shares of Common Stock equal to the number of shares of Common Stock surrendered
as part or all of the exercise price of such Option; (2) have an expiration date
which is the same as the expiration date of the Option the exercise of which
gave rise to such Re-Load Option; and (3) have an exercise price which is equal
to one hundred percent (100%) of the Fair Market Value of the Common Stock
subject to the Re-Load Option on the date of exercise of the original Option.
Notwithstanding the foregoing, a Re-Load Option shall be subject to the same
exercise price and term provisions heretofore described for Options under the
Plan.

            (iii) Any such Re-Load Option may be an Incentive Stock Option or a
Nonstatutory Stock Option, as the Board may designate at the time of the grant
of the original Option; provided, however, that the designation of any Re-Load
Option as an Incentive Stock Option shall be subject to the one hundred thousand
dollar ($100,000) annual limitation on the exercisability of Incentive Stock
Options described in subsection 10(d) and in Section 422(d) of the Code. There
shall be no Re-Load Options on a Re-Load Option. Any such Re-Load Option shall
be subject to the availability of sufficient shares of Common Stock under
subsection 4(a) and the "Section 162(m) Limitation" on the grants of Options
under subsection 5(c) and shall be subject to such other terms and conditions as
the Board may determine which are not inconsistent with the express provisions
of the Plan regarding the terms of Options.

7.    PROVISIONS OF STOCK AWARDS OTHER THAN OPTIONS.

      (a) STOCK BONUS AWARDS. Each stock bonus agreement shall be in such form
and shall contain such terms and conditions as the Board shall deem appropriate.
The terms and conditions of stock bonus agreements may change from time to time,
and the terms and conditions of separate stock bonus agreements need not be
identical, but each stock bonus agreement shall include (through incorporation
of provisions hereof by reference in the agreement or otherwise) the substance
of each of the following provisions:


                                       12
<PAGE>
            (i) CONSIDERATION. A stock bonus may be awarded in consideration for
past services actually rendered to the Company or an Affiliate for its benefit.

            (ii) VESTING. Shares of Common Stock awarded under the stock bonus
agreement may, but need not, be subject to an automatic unvested share
reacquisition right in favor of the Company in accordance with a vesting
schedule to be determined by the Board, as described further in Section
7(a)(iii) below. Stock bonus awards granted prior to the Listing Date to an
Employee who is not an Officer, Director or Consultant shall provide for vesting
of the total number of shares of Common Stock at a rate of at least twenty
percent (20%) per year over five (5) years from the date the stock bonus award
was granted, subject to reasonable conditions such as continued employment.
Stock bonus awards granted prior to the Listing Date to Officers, Directors or
Consultants may be made exercisable, subject to conditions such as continued
employment or performance criteria, at any time or during any period established
by the Company.

            (iii) TERMINATION OF PARTICIPANT'S CONTINUOUS SERVICE. In the event
a Participant's Continuous Service terminates, the Company shall automatically
reacquire all of the shares of Common Stock held by the Participant which have
not vested as of the date of termination under the terms of the stock bonus
agreement.

            (iv) RIGHT OF REPURCHASE. The stock bonus award may, but need not,
include a provision whereby the Company may elect, prior to the Listing Date, to
repurchase all or any part of the vested shares of Common Stock granted to the
Participant pursuant to a stock bonus award.

      (b) RESTRICTED STOCK PURCHASE AWARDS. Each restricted stock purchase
agreement shall be in such form and shall contain such terms and conditions as
the Board shall deem appropriate. The terms and conditions of the restricted
stock purchase agreements may change from time to time, and the terms and
conditions of separate restricted stock purchase agreements need not be
identical, but each restricted stock purchase agreement shall include (through
incorporation of provisions hereof by reference in the agreement or otherwise)
the substance of each of the following provisions:

            (i) PURCHASE PRICE. Subject to the provisions of subsection 5(b)
regarding Ten Percent Stockholders, the purchase price under each restricted
stock purchase agreement shall be such amount as the Board shall determine and
designate in such restricted stock purchase agreement. For restricted stock
awards made prior to the Listing Date, the purchase price shall not be less than
eighty-five percent (85%) of the Common Stock's Fair Market Value on the date
such award is made or at the time the purchase is consummated. For restricted
stock awards made on or after the Listing Date, the purchase price shall be
determined by the Board.

            (ii) CONSIDERATION. The purchase price of Common Stock acquired
pursuant to the restricted stock purchase agreement shall be paid either: (i) in
cash at the time of purchase; (ii) at the discretion of the Board, according to
a deferred payment or other similar arrangement with the Participant; or (iii)
in any other form of legal consideration that may be acceptable to the Board in
its discretion; provided, however, that at any time that the Company is


                                       13
<PAGE>
incorporated in Delaware, the payment of the Common Stock's "par value," as
defined in the Delaware General Corporation Law, shall not be made by deferred
payment.

            (iii) VESTING. Subject to the "Repurchase Limitation" in subsection
10(h), shares of Common Stock acquired under the restricted stock purchase
agreement may, but need not, be subject to a share repurchase option in favor of
the Company in accordance with a vesting schedule to be determined by the Board,
as described further in Section 7(b)(iv) below. Restricted stock purchase awards
granted prior to the Listing Date to an Employee who is not an Officer, Director
or Consultant shall provide for vesting of the total number of shares of Common
Stock at a rate of at least twenty percent (20%) per year over five (5) years
from the date the restricted stock purchase award was granted, subject to
reasonable conditions such as continued employment. Restricted stock purchase
awards granted prior to the Listing Date to Officers, Directors or Consultants
may be made exercisable, subject to conditions such as continued employment or
performance criteria, at any time or during any period established by the
Company.

            (iv) TERMINATION OF PARTICIPANT'S CONTINUOUS SERVICE. Subject to the
"Repurchase Limitation" in subsection 10(h), in the event a Participant's
Continuous Service terminates, the Company may repurchase or otherwise reacquire
any or all of the shares of Common Stock held by the Participant which have not
vested as of the date of termination under the terms of the restricted stock
purchase agreement.

            (v) RIGHT OF REPURCHASE. The restricted stock purchase agreement
may, but need not, include a provision whereby the Company may elect, prior to
the Listing Date, to repurchase all or any part of the vested shares of Common
Stock granted to the Participant pursuant a restricted stock purchase award.

            (vi) TRANSFERABILITY. For a restricted stock purchase award made
before the Listing Date, rights to acquire shares of Common Stock under the
restricted stock purchase agreement shall not be transferable except by will or
by the laws of descent and distribution and shall be exercisable during the
lifetime of the Participant only by the Participant. For a restricted stock
award made on or after the Listing Date, rights to acquire shares of Common
Stock under the restricted stock purchase agreement shall be transferable by the
Participant only upon such terms and conditions as are set forth in the
restricted stock purchase agreement, as the Board shall determine in its
discretion, so long as Common Stock awarded under the restricted stock purchase
agreement remains subject to the terms of the restricted stock purchase
agreement.

8.    COVENANTS OF THE COMPANY.

      (a) AVAILABILITY OF SHARES. During the terms of the Stock Awards, the
Company shall keep available at all times the number of shares of Common Stock
required to satisfy such Stock Awards.

      (b) SECURITIES LAW COMPLIANCE. The Company shall seek to obtain from each
regulatory commission or agency having jurisdiction over the Plan such authority
as may be required to grant Stock Awards and to issue and sell shares of Common
Stock upon exercise of


                                       14
<PAGE>
the Stock Awards; provided, however, that this undertaking shall not require the
Company to register under the Securities Act the Plan, any Stock Award or any
Common Stock issued or issuable pursuant to any such Stock Award. If, after
reasonable efforts, the Company is unable to obtain from any such regulatory
commission or agency the authority which counsel for the Company deems necessary
for the lawful issuance and sale of Common Stock under the Plan, the Company
shall be relieved from any liability for failure to issue and sell Common Stock
upon exercise of such Stock Awards unless and until such authority is obtained.

9.    USE OF PROCEEDS FROM STOCK.

      Proceeds from the sale of Common Stock pursuant to Stock Awards shall
constitute general funds of the Company.

10.   MISCELLANEOUS.

      (a) ACCELERATION OF EXERCISABILITY AND VESTING. The Board shall have the
power to accelerate the time at which a Stock Award may first be exercised or
the time during which a Stock Award or any part thereof will vest,
notwithstanding the provisions in the Stock Award stating the time at which it
may first be exercised or the time during which it will vest.

      (b) STOCKHOLDER RIGHTS. No Participant shall be deemed to be the holder
of, or to have any of the rights of a holder with respect to, any shares of
Common Stock subject to such Stock Award unless and until such Participant has
satisfied all requirements for exercise of the Stock Award pursuant to its
terms.

      (c) NO EMPLOYMENT OR OTHER SERVICE RIGHTS. Nothing in the Plan or any
instrument executed or Stock Award granted pursuant thereto shall confer upon
any Participant any right to continue to serve the Company or an Affiliate in
the capacity in effect at the time the Stock Award was granted or shall affect
the right of the Company or an Affiliate to terminate (i) the employment of an
Employee with or without notice and with or without cause, for any reason or no
reason, (ii) the service of a Consultant pursuant to the terms of such
Consultant's agreement with the Company or an Affiliate or (iii) the service of
a Director pursuant to the Bylaws of the Company or an Affiliate, and any
applicable provisions of the corporate law of the state in which the Company or
the Affiliate is incorporated, as the case may be.

      (d) INCENTIVE STOCK OPTION $100,000 LIMITATION. To the extent that the
aggregate Fair Market Value (determined at the time of grant) of Common Stock
with respect to which Incentive Stock Options are exercisable for the first time
by any Optionholder during any calendar year (under all plans of the Company and
its Affiliates) exceeds one hundred thousand dollars ($100,000), the Options or
portions thereof which exceed such limit (according to the order in which they
were granted) shall be treated as Nonstatutory Stock Options.

      (e) INVESTMENT ASSURANCES. The Company may require a Participant, as a
condition of exercising or acquiring Common Stock under any Stock Award, (i) to
give written assurances satisfactory to the


                                       15
<PAGE>
Company as to the Participant's knowledge and experience in financial and
business matters and/or to employ a purchaser representative reasonably
satisfactory to the Company who is knowledgeable and experienced in financial
and business matters and that he or she is capable of evaluating, alone or
together with the purchaser representative, the merits and risks of exercising
the Stock Award; and (ii) to give written assurances satisfactory to the Company
stating that the Participant is acquiring Common Stock subject to the Stock
Award for the Participant's own account and not with any present intention of
selling or otherwise distributing the Common Stock. The foregoing requirements,
and any assurances given pursuant to such requirements, shall be inoperative if
(1) the issuance of the shares of Common Stock upon the exercise or acquisition
of Common Stock under the Stock Award has been registered under a then currently
effective registration statement under the Securities Act or (2) as to any
particular requirement, a determination is made by counsel for the Company that
such requirement need not be met in the circumstances under the then applicable
securities laws. The Company may, upon advice of counsel to the Company, place
legends on stock certificates issued under the Plan as such counsel deems
necessary or appropriate in order to comply with applicable securities laws,
including, but not limited to, legends restricting the transfer of the Common
Stock.

      (f) WITHHOLDING OBLIGATIONS. To the extent provided by the terms of a
Stock Award Agreement, the Participant may satisfy any federal, state or local
tax withholding obligation relating to the exercise or acquisition of Common
Stock under a Stock Award by any of the following means (in addition to the
Company's right to withhold from any compensation paid to the Participant by the
Company) or by a combination of such means: (i) tendering a cash payment; (ii)
authorizing the Company to withhold shares of Common Stock from the shares of
Common Stock otherwise issuable to the Participant as a result of the exercise
or acquisition of Common Stock under the Stock Award, provided, however, that no
shares of Common Stock are withheld with a value exceeding the minimum amount of
tax required to be withheld by law; or (iii) delivering to the Company owned and
unencumbered shares of Common Stock.

      (g) INFORMATION OBLIGATION. Prior to the Listing Date, to the extent
required by Section 260.140.46 of Title 10 of the California Code of
Regulations, the Company shall deliver financial statements to Participants at
least annually. This subsection 10(g) shall not apply to key Employees whose
duties in connection with the Company assure them access to equivalent
information.

      (h) REPURCHASE LIMITATION. The terms of any repurchase option shall be
specified in the Stock Award and may be either at Fair Market Value at the time
of repurchase or at not less than the original purchase price. To the extent
required by Section 260.140.41 and Section 260.140.42 of Title 10 of the
California Code of Regulations at the time a Stock Award is made, any repurchase
option contained in a Stock Award granted prior to the Listing Date to a person
who is not an Officer, Director or Consultant shall be upon the terms described
below:

            (i) FAIR MARKET VALUE. If the repurchase option gives the Company
the right to repurchase the shares of Common Stock upon termination of
employment at not less than the Fair Market Value of the shares of Common Stock
to be purchased on the date of termination of Continuous Service, then (i) the
right to repurchase shall be exercised for cash or cancellation of purchase
money indebtedness for the shares of Common Stock within ninety (90) days of


                                       16
<PAGE>
termination of Continuous Service (or in the case of shares of Common Stock
issued upon exercise of Stock Awards after such date of termination, within
ninety (90) days after the date of the exercise) or such longer period as may be
agreed to by the Company and the Participant (for example, for purposes of
satisfying the requirements of Section 1202(c)(3) of the Code regarding
"qualified small business stock") and (ii) the right terminates when the shares
of Common Stock become publicly traded.

            (ii) ORIGINAL PURCHASE PRICE. If the repurchase option gives the
Company the right to repurchase the shares of Common Stock upon termination of
Continuous Service at the original purchase price, then (i) the right to
repurchase at the original purchase price shall lapse at the rate of at least
twenty percent (20%) of the shares of Common Stock per year over five (5) years
from the date the Stock Award is granted (without respect to the date the Stock
Award was exercised or became exercisable) and (ii) the right to repurchase
shall be exercised for cash or cancellation of purchase money indebtedness for
the shares of Common Stock within ninety (90) days of termination of Continuous
Service (or in the case of shares of Common Stock issued upon exercise of
Options after such date of termination, within ninety (90) days after the date
of the exercise) or such longer period as may be agreed to by the Company and
the Participant (for example, for purposes of satisfying the requirements of
Section 1202(c)(3) of the Code regarding "qualified small business stock").

11.   ADJUSTMENTS UPON CHANGES IN STOCK.

      (a) CAPITALIZATION ADJUSTMENTS. If any change is made in the Common Stock
subject to the Plan, or subject to any Stock Award, without the receipt of
consideration by the Company (through merger, consolidation, reorganization,
recapitalization, reincorporation, stock dividend, dividend in property other
than cash, stock split, liquidating dividend, combination of shares, exchange of
shares, change in corporate structure or other transaction not involving the
receipt of consideration by the Company), the Plan will be appropriately
adjusted in the class(es) and maximum number of securities subject to the Plan
pursuant to subsection 4(a) and the maximum number of securities subject to
award to any person pursuant to subsection 5(c), and the outstanding Stock
Awards will be appropriately adjusted in the class(es) and number of securities
and price per share of Common Stock subject to such outstanding Stock Awards.
The Board shall make such adjustments, and its determination shall be final,
binding and conclusive. (The conversion of any convertible securities of the
Company shall not be treated as a transaction "without receipt of consideration"
by the Company.)

      (b) CHANGE IN CONTROL--DISSOLUTION OR LIQUIDATION. In the event of a
dissolution or liquidation of the Company, then all outstanding Stock Awards
shall terminate immediately prior to such event.

      (c) CHANGE IN CONTROL--ASSET SALE, MERGER, CONSOLIDATION OR REVERSE
MERGER. In the event of (i) a sale, lease or other disposition of all or
substantially all of the assets of the Company, (ii) a merger or consolidation
in which the Company is not the surviving corporation or (iii) a reverse merger
in which the Company is the surviving corporation but the shares of Common Stock
outstanding immediately preceding the merger are converted by virtue of the
merger into other property, whether in the form of securities, cash or
otherwise, then any


                                       17
<PAGE>
surviving corporation or acquiring corporation shall assume or continue any
Stock Awards outstanding under the Plan or shall substitute similar stock awards
(including an award to acquire the same consideration paid to the stockholders
in the transaction described in this subsection 11(c) for those outstanding
under the Plan). In the event any surviving corporation or acquiring corporation
refuses to assume or continue such Stock Awards or to substitute similar stock
awards for those outstanding under the Plan, then with respect to Stock Awards
held by Participants whose Continuous Service has not terminated, the vesting of
such Stock Awards (and, if applicable, the time during which such Stock Awards
may be exercised) shall be accelerated in full, and the Stock Awards shall
terminate if not exercised (if applicable) at or prior to such event. With
respect to any other Stock Awards outstanding under the Plan, such Stock Awards
shall terminate if not exercised (if applicable) prior to such event.

12.   AMENDMENT OF THE PLAN AND STOCK AWARDS.

      (a) AMENDMENT OF PLAN. The Board at any time, and from time to time, may
amend the Plan. However, except as provided in Section 11 relating to
adjustments upon changes in Common Stock, no amendment shall be effective unless
approved by the stockholders of the Company to the extent stockholder approval
is necessary to satisfy the requirements of Section 422 of the Code, Rule 16b-3
or any NASDAQ or securities exchange listing requirements.

      (b) STOCKHOLDER APPROVAL. The Board may, in its sole discretion, submit
any other amendment to the Plan for stockholder approval, including, but not
limited to, amendments to the Plan intended to satisfy the requirements of
Section 162(m) of the Code and the regulations thereunder regarding the
exclusion of performance-based compensation from the limit on corporate
deductibility of compensation paid to certain executive officers.

      (c) CONTEMPLATED AMENDMENTS. It is expressly contemplated that the Board
may amend the Plan in any respect the Board deems necessary or advisable to
provide eligible Employees with the maximum benefits provided or to be provided
under the provisions of the Code and the regulations promulgated thereunder
relating to Incentive Stock Options and/or to bring the Plan and/or Incentive
Stock Options granted under it into compliance therewith.

      (d) NO IMPAIRMENT OF RIGHTS. Rights under any Stock Award granted before
amendment of the Plan shall not be impaired by any amendment of the Plan unless
(i) the Company requests the consent of the Participant and (ii) the Participant
consents in writing.

      (e) AMENDMENT OF STOCK AWARDS. The Board at any time, and from time to
time, may amend the terms of any one or more Stock Awards; provided, however,
that the rights under any Stock Award shall not be impaired by any such
amendment unless (i) the Company requests the consent of the Participant and
(ii) the Participant consents in writing.

13.   TERMINATION OR SUSPENSION OF THE PLAN.

      (a) PLAN TERM. The Board may suspend or terminate the Plan at any time.
Unless sooner terminated, the Plan shall terminate on the day before the tenth
(10th) anniversary of the date the Plan is adopted by the Board or approved by
the stockholders of the Company,


                                       18
<PAGE>
whichever is earlier. No Stock Awards may be granted under the Plan while the
Plan is suspended or after it is terminated.

      (b) NO IMPAIRMENT OF RIGHTS. Suspension or termination of the Plan shall
not impair rights and obligations under any Stock Award granted while the Plan
is in effect except with the written consent of the Participant.

14.   EFFECTIVE DATE OF PLAN.

      The Plan shall become effective as determined by the Board, but no Stock
Award shall be exercised (or, in the case of a stock bonus, shall be granted)
unless and until the Plan has been approved by the stockholders of the Company,
which approval shall be within twelve (12) months before or after the date the
Plan is adopted by the Board.

15.   CHOICE OF LAW.

      The law of the State of California shall govern all questions concerning
the construction, validity and interpretation of this Plan, without regard to
such state's conflict of laws rules.


                                       19
<PAGE>
                            STRUCTURAL GENOMIX, INC.
                           2000 EQUITY INCENTIVE PLAN

                             STOCK OPTION AGREEMENT
                   (INCENTIVE AND NONSTATUTORY STOCK OPTIONS)

      Pursuant to your Stock Option Grant Notice ("Grant Notice") and this Stock
Option Agreement, Structural GenomiX, Inc. (the "Company") has granted you an
option under its 2000 Equity Incentive Plan (the "Plan") to purchase the number
of shares of the Company's Common Stock indicated in your Grant Notice at the
exercise price indicated in your Grant Notice. Defined terms not explicitly
defined in this Stock Option Agreement but defined in the Plan shall have the
same definitions as in the Plan.

      The details of your option are as follows:

      1. VESTING. Subject to the limitations contained herein, your option will
vest as provided in your Grant Notice, provided that vesting will cease upon the
termination of your Continuous Service.

      2. NUMBER OF SHARES AND EXERCISE PRICE. The number of shares of Common
Stock subject to your option and your exercise price per share referenced in
your Grant Notice may be adjusted from time to time for Capitalization
Adjustments, as provided in the Plan.

      3. EXERCISE PRIOR TO VESTING ("EARLY EXERCISE"). If permitted in your
Grant Notice (i.e., the "Exercise Schedule" indicates that "Early Exercise" of
your option is permitted) and subject to the provisions of your option, you may
elect at any time that is both (i) during the period of your Continuous Service
and (ii) during the term of your option, to exercise all or part of your option,
including the nonvested portion of your option; provided, however, that:

            (a) a partial exercise of your option shall be deemed to cover first
vested shares of Common Stock and then the earliest vesting installment of
unvested shares of Common Stock;

            (b) any shares of Common Stock so purchased from installments that
have not vested as of the date of exercise shall be subject to the purchase
option in favor of the Company as described in the Company's form of Early
Exercise Stock Purchase Agreement;

            (c) you shall enter into the Company's form of Early Exercise Stock
Purchase Agreement with a vesting schedule that will result in the same vesting
as if no early exercise had occurred; and

            (d) if your option is an incentive stock option, then, as provided
in the Plan, to the extent that the aggregate Fair Market Value (determined at
the time of grant) of the shares of Common Stock with respect to which your
option plus all other incentive stock options you hold are exercisable for the
first time by you during any calendar year (under all plans of the


                                        1
<PAGE>
Company and its Affiliates) exceeds one hundred thousand dollars ($100,000),
your option(s) or portions thereof that exceed such limit (according to the
order in which they were granted) shall be treated as nonstatutory stock
options.

      4. METHOD OF PAYMENT. Payment of the exercise price is due in full upon
exercise of all or any part of your option. You may elect to make payment of the
exercise price in cash or by check or in any other manner PERMITTED BY YOUR
GRANT NOTICE, which may include one or more of the following:

            (a) In the Company's sole discretion at the time your option is
exercised and provided that at the time of exercise the Common Stock is publicly
traded and quoted regularly in The Wall Street Journal, pursuant to a program
developed under Regulation T as promulgated by the Federal Reserve Board that,
prior to the issuance of Common Stock, results in either the receipt of cash (or
check) by the Company or the receipt of irrevocable instructions to pay the
aggregate exercise price to the Company from the sales proceeds.

            (b) Provided that at the time of exercise the Common Stock is
publicly traded and quoted regularly in The Wall Street Journal, by delivery of
already-owned shares of Common Stock either that you have held for the period
required to avoid a charge to the Company's reported earnings (generally six
months) or that you did not acquire, directly or indirectly from the Company,
that are owned free and clear of any liens, claims, encumbrances or security
interests, and that are valued at Fair Market Value on the date of exercise.
"Delivery" for these purposes, in the sole discretion of the Company at the time
you exercise your option, shall include delivery to the Company of your
attestation of ownership of such shares of Common Stock in a form approved by
the Company. Notwithstanding the foregoing, you may not exercise your option by
tender to the Company of Common Stock to the extent such tender would violate
the provisions of any law, regulation or agreement restricting the redemption of
the Company's stock.

            (c) Pursuant to the following deferred payment alternative:

                  (i) Not less than one hundred percent (100%) of the aggregate
exercise price, plus accrued interest, shall be due five (5) years from date of
exercise or, at the Company's election, upon termination of your Continuous
Service.

                  (ii) Interest shall be charged at the minimum rate of interest
necessary to avoid the treatment as interest, under any applicable provisions of
the Code, of any portion of any amounts other than amounts stated to be interest
under the deferred payment arrangement.

                  (iii) At any time that the Company is incorporated in
Delaware, payment of the Common Stock's "par value," as defined in the Delaware
General Corporation Law, shall be made in cash and not by deferred payment.

                  (iv) In order to elect the deferred payment alternative, you
must, as a part of your written notice of exercise, give notice of the election
of this payment alternative and, in order to secure the payment of the deferred
exercise price to the Company hereunder, if the


                                       2
<PAGE>
Company so requests, you must tender to the Company a promissory note and a
security agreement covering the purchased shares of Common Stock, both in form
and substance satisfactory to the Company, or such other or additional
documentation as the Company may request.

      5. WHOLE SHARES. You may exercise your option only for whole shares of
Common Stock.

      6. SECURITIES LAW COMPLIANCE. Notwithstanding anything to the contrary
contained herein, you may not exercise your option unless the shares of Common
Stock issuable upon such exercise are then registered under the Securities Act
or, if such shares of Common Stock are not then so registered, the Company has
determined that such exercise and issuance would be exempt from the registration
requirements of the Securities Act. The exercise of your option must also comply
with other applicable laws and regulations governing your option, and you may
not exercise your option if the Company determines that such exercise would not
be in material compliance with such laws and regulations.

      7. TERM. You may not exercise your option before the commencement of its
term or after its term expires. The term of your option commences on the Date of
Grant and expires upon the EARLIEST of the following:

            (a) three (3) months after the termination of your Continuous
Service for any reason other than your Disability or death, provided that if
during any part of such three (3) month period your option is not exercisable
solely because of the condition set forth in the preceding paragraph relating to
"Securities Law Compliance," your option shall not expire until the earlier of
the Expiration Date or until it shall have been exercisable for an aggregate
period of three (3) months after the termination of your Continuous Service;

            (b) twelve (12) months after the termination of your Continuous
Service due to your Disability;

            (c) eighteen (18) months after your death if you die either during
your Continuous Service or within three (3) months after your Continuous Service
terminates;

            (d) the Expiration Date indicated in your Grant Notice; or

            (e) the day before the tenth (10th) anniversary of the Date of
Grant.

      If your option is an incentive stock option, note that, to obtain the
federal income tax advantages associated with an "incentive stock option," the
Code requires that at all times beginning on the date of grant of your option
and ending on the day three (3) months before the date of your option's
exercise, you must be an employee of the Company or an Affiliate, except in the
event of your death or Disability. The term Disability as used in this Agreement
and in the Plan exceeds the definition prescribed in Section 22(e)(3) of the
Code. The Company has provided for extended exercisability of your option under
certain circumstances for your benefit but cannot guarantee that your option
will necessarily be treated as an "incentive stock option" if


                                       3
<PAGE>
you continue to provide services to the Company or an Affiliate as a Consultant
or Director after your employment terminates or if you otherwise exercise your
option more than three (3) months after the date your employment terminates.

      8.    EXERCISE.

            (a) You may exercise the vested portion of your option (and the
unvested portion of your option if your Grant Notice so permits) during its term
by delivering a Notice of Exercise (in a form designated by the Company)
together with the exercise price to the Secretary of the Company, or to such
other person as the Company may designate, during regular business hours,
together with such additional documents as the Company may then require.

            (b) By exercising your option you agree that, as a condition to any
exercise of your option, the Company may require you to enter into an
arrangement providing for the payment by you to the Company of any tax
withholding obligation of the Company arising by reason of (1) the exercise of
your option, (2) the lapse of any substantial risk of forfeiture to which the
shares of Common Stock are subject at the time of exercise, or (3) the
disposition of shares of Common Stock acquired upon such exercise.

            (c) If your option is an incentive stock option, by exercising your
option you agree that you will notify the Company in writing within fifteen (15)
days after the date of any disposition of any of the shares of the Common Stock
issued upon exercise of your option that occurs within two (2) years after the
date of your option grant or within one (1) year after such shares of Common
Stock are transferred upon exercise of your option.

            (d) By exercising your option you agree that the Company (or a
representative of the underwriter(s)) may, in connection with the first
underwritten registration of the offering of any securities of the Company under
the Securities Act, require that you not sell, dispose of, transfer, make any
short sale of, grant any option for the purchase of, or enter into any hedging
or similar transaction with the same economic effect as a sale, any shares of
Common Stock or other securities of the Company held by you, for a period of
time specified by the underwriter(s) (not to exceed one hundred eighty (180)
days) following the effective date of the registration statement of the Company
filed under the Securities Act. You further agree to execute and deliver such
other agreements as may be reasonably requested by the Company and/or the
underwriter(s) that are consistent with the foregoing or that are necessary to
give further effect thereto. In order to enforce the foregoing covenant, the
Company may impose stop-transfer instructions with respect to your shares of
Common Stock until the end of such period.

      9.    TRANSFERABILITY. Your option is not transferable, except by will or
by the laws of descent and distribution, and is exercisable during your life
only by you. Notwithstanding the foregoing, by delivering written notice to the
Company, in a form satisfactory to the Company, you may designate a third party
who, in the event of your death, shall thereafter be entitled to exercise your
option.

      10.   RIGHT OF FIRST REFUSAL. Shares of Common Stock that you acquire upon
exercise of your option are subject to any right of first refusal that may be
described in the


                                       4
<PAGE>
Company's bylaws in effect at such time the Company elects to exercise its
right. The Company's right of first refusal shall expire on the Listing Date.

      11.   RIGHT OF REPURCHASE. To the extent provided in the Early Exercise
Stock Purchase Agreement by which you acquired shares of Common Stock, the
Company shall have the right to repurchase all or any part of the shares of
Common Stock you acquire pursuant to the early exercise of your option.

      12.   OPTION NOT A SERVICE CONTRACT. Your option is not an employment or
service contract, and nothing in your option shall be deemed to create in any
way whatsoever any obligation on your part to continue in the employ of the
Company or an Affiliate, or of the Company or an Affiliate to continue your
employment. In addition, nothing in your option shall obligate the Company or an
Affiliate, their respective shareholders, Boards of Directors, Officers or
Employees to continue any relationship that you might have as a Director or
Consultant for the Company or an Affiliate.

      13.   WITHHOLDING OBLIGATIONS.

            (a) At the time you exercise your option, in whole or in part, or at
any time thereafter as requested by the Company, you hereby authorize
withholding from payroll and any other amounts payable to you, and otherwise
agree to make adequate provision for (including by means of a "same day sale"
pursuant to a program developed under Regulation T as promulgated by the Federal
Reserve Board to the extent permitted by the Company), any sums required to
satisfy the federal, state, local and foreign tax withholding obligations of the
Company or an Affiliate, if any, which arise in connection with your option.

            (b) Upon your request and subject to approval by the Company, in its
sole discretion, and compliance with any applicable conditions or restrictions
of law, the Company may withhold from fully vested shares of Common Stock
otherwise issuable to you upon the exercise of your option a number of whole
shares of Common Stock having a Fair Market Value, determined by the Company as
of the date of exercise, not in excess of the minimum amount of tax required to
be withheld by law. If the date of determination of any tax withholding
obligation is deferred to a date later than the date of exercise of your option,
share withholding pursuant to the preceding sentence shall not be permitted
unless you make a proper and timely election under Section 83(b) of the Code,
covering the aggregate number of shares of Common Stock acquired upon such
exercise with respect to which such determination is otherwise deferred, to
accelerate the determination of such tax withholding obligation to the date of
exercise of your option. Notwithstanding the filing of such election, shares of
Common Stock shall be withheld solely from fully vested shares of Common Stock
determined as of the date of exercise of your option that are otherwise issuable
to you upon such exercise. Any adverse consequences to you arising in connection
with such share withholding procedure shall be your sole responsibility.

            (c) You may not exercise your option unless the tax withholding
obligations of the Company and/or any Affiliate are satisfied. Accordingly, you
may not be able to exercise your option when desired even though your option is
vested, and the Company shall have no


                                       5
<PAGE>
obligation to issue a certificate for such shares of Common Stock or release
such shares of Common Stock from any escrow provided for herein.

      14. NOTICES. Any notices provided for in your option or the Plan shall be
given in writing and shall be deemed effectively given upon receipt or, in the
case of notices delivered by mail by the Company to you, five (5) days after
deposit in the United States mail, postage prepaid, addressed to you at the last
address you provided to the Company.

      15. GOVERNING PLAN DOCUMENT. Your option is subject to all the provisions
of the Plan, the provisions of which are hereby made a part of your option, and
is further subject to all interpretations, amendments, rules and regulations
which may from time to time be promulgated and adopted pursuant to the Plan. In
the event of any conflict between the provisions of your option and those of the
Plan, the provisions of the Plan shall control.


                                       6
<PAGE>
                            STRUCTURAL GENOMIX, INC.
                            STOCK OPTION GRANT NOTICE
                          (2000 EQUITY INCENTIVE PLAN)

Structural GenomiX, Inc. (the "Company"), pursuant to its 2000 Equity Incentive
Plan (the "Plan"), hereby grants to Optionholder an option to purchase the
number of shares of the Company's Common Stock set forth below. This option is
subject to all of the terms and conditions as set forth herein and in the Stock
Option Agreement, the Plan and the Notice of Exercise, all of which are attached
hereto and incorporated herein in their entirety.

Optionholder:                         EMPLOYEE
Date of Grant:
Vesting Commencement Date:
Number of Shares Subject to Option:
Exercise Price (Per Share):
Total Exercise Price:
Expiration Date:

TYPE OF GRANT:      [ ]  Incentive Stock Option     [ ]  Nonstatutory Stock
                                                         Option

EXERCISE SCHEDULE:  [ ]  Same as Vesting Schedule   [ ]  Early Exercise
                                                         Permitted

VESTING SCHEDULE:   [                                 ]

PAYMENT:            By one or a combination of the following items
                    (described in the Stock Option Agreement):

                          By cash or check
                          Pursuant to a Regulation T Program if the Shares are
                            publicly traded
                          By delivery of already-owned shares if the Shares are
                            publicly traded
                          By deferred payment

ADDITIONAL TERMS/ACKNOWLEDGEMENTS: The undersigned Optionholder acknowledges
receipt of, and understands and agrees to, this Grant Notice, the Stock Option
Agreement and the Plan. Optionholder further acknowledges that as of the Date of
Grant, this Grant Notice, the Stock Option Agreement and the Plan set forth the
entire understanding between Optionholder and the Company regarding the
acquisition of stock in the Company and supersede all prior oral and written
agreements on that subject with the exception of (i) stock awards previously
granted and delivered to Optionholder under the Plan, and (ii) the following
agreements only:

      OTHER AGREEMENTS:
                                    ------------------------------------------
                                    ------------------------------------------

STRUCTURAL GENOMIX, INC.                  EMPLOYEE:


--------------------------------------    --------------------------------------
Michael G. Grey
President & Chief Executive Officer

Date:                                     Date:
      --------------------------------           -------------------------------

ATTACHMENTS: Stock Option Agreement, 2000 Equity Incentive Plan and Notice of
Exercise