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AMENDED AND RESTATED
BYLAWS
OF
SGX PHARMACEUTICALS, INC.
 ARTICLE 1
 OFFICES
 1.1 REGISTERED OFFICE.
 1.2 OTHER OFFICES.
 ARTICLE 2
 CORPORATE SEAL
 2.1 CORPORATE SEAL.
 ARTICLE 3
 STOCKHOLDERS MEETINGS
 3.1 PLACE OF MEETINGS. DGCL
 3.2 ANNUAL MEETINGS.
 (a)
 1.




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(i)
 (ii)
 (iii)
 (b) 1934 ACT
 2.




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SOLICITATION NOTICE
 (c)
 (d)
 (e)
 (f)
 3.




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3.3 SPECIAL MEETINGS.
 (a)
 (b)
 (c)
 3.4 NOTICE OF MEETINGS.
 4.




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3.5 QUORUM.
 3.6 ADJOURNMENT AND NOTICE OF ADJOURNED MEETINGS.
 5.




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3.7 VOTING RIGHTS.
 3.8 JOINT OWNERS OF STOCK.
 3.9 LIST OF STOCKHOLDERS.
 3.10 ACTION WITHOUT MEETING.
 6.




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3.11 ORGANIZATION.
 (a)
 (b)
 ARTICLE 4
 DIRECTORS
 4.1 NUMBER AND TERM OF OFFICE.
 4.2 POWERS.
 4.3 CLASSES OF DIRECTORS.
 7.




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4.4 VACANCIES.
 4.5 RESIGNATION.
 4.6 REMOVAL.
 (a)
 (b)
 8.




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4.7 MEETINGS.
 (a) REGULAR MEETINGS.
 (b) SPECIAL MEETINGS.
 (c) MEETINGS BY ELECTRONIC COMMUNICATIONS EQUIPMENT.
 (d) NOTICE OF SPECIAL MEETINGS.
 (e) WAIVER OF NOTICE
 9.




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4.8 QUORUM AND VOTING.
 (a)
 (b)
 (c) ACTION WITHOUT MEETING.
 4.9 FEES AND COMPENSATION.
 4.10 COMMITTEES.
 (a) EXECUTIVE COMMITTEE.
 (b) OTHER COMMITTEES.
 10.




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(c) TERM.
 (d) MEETINGS.
 4.11 ORGANIZATION.
 11.




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ARTICLE 5
 OFFICERS
 5.1 OFFICERS DESIGNATED.
 5.2 TENURE AND DUTIES OF OFFICERS.
 (a) GENERAL.
 (b) DUTIES OF CHAIRMAN OF THE BOARD OF DIRECTORS.
 (c) DUTIES OF PRESIDENT.
 (d) DUTIES OF VICE PRESIDENTS.
 12.




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(e) DUTIES OF SECRETARY.
 (f) DUTIES OF CHIEF FINANCIAL OFFICER.
 5.3 DELEGATION OF AUTHORITY.
 5.4 RESIGNATIONS.
 5.5 REMOVAL.
 13.




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ARTICLE 6
 EXECUTION OF CORPORATE INSTRUMENTS AND VOTING
OF SECURITIES OWNED BY THE CORPORATION
 6.1 EXECUTION OF CORPORATE INSTRUMENTS.
   6.2 VOTING OF SECURITIES OWNED BY THE CORPORATION.
 ARTICLE 7
 SHARES OF STOCK
 7.1 FORM AND EXECUTION OF CERTIFICATES.
 14.




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7.2 LOST CERTIFICATES.
 7.3 TRANSFERS.
 (a)
 (b)
 7.4 FIXING RECORD DATES.
 (a)
 15.




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(b)
 7.5 REGISTERED STOCKHOLDERS.
 ARTICLE 8
 OTHER SECURITIES OF THE CORPORATION
 8.1 EXECUTION OF OTHER SECURITIES.
 16.




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ARTICLE 9
 DIVIDENDS
 9.1 DECLARATION OF DIVIDENDS.
 9.2 DIVIDEND RESERVE.
 ARTICLE 10
 FISCAL YEAR
 10.1 FISCAL YEAR.
 ARTICLE 11
 INDEMNIFICATION
 11.1 INDEMNIFICATION OF DIRECTORS, EXECUTIVE OFFICERS, OTHER OFFICERS, EMPLOYEES AND OTHER
AGENTS.
 (a) DIRECTORS AND EXECUTIVE OFFICERS.
 (b) OTHER OFFICERS, EMPLOYEES AND OTHER AGENTS.
 17.




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(c) EXPENSES. undertaking final adjudication
  (d) ENFORCEMENT.
 18.




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(e) NON-EXCLUSIVITY OF RIGHTS.
 (f) SURVIVAL OF RIGHTS.
 (g) INSURANCE.
 (h) AMENDMENTS.
 (i) SAVING CLAUSE.
 19.




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(j) CERTAIN DEFINITIONS.
 (1)
 (2)
 (3)
 (4)
 (5)
 20.




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ARTICLE 12
 NOTICES
 12.1 NOTICES.
 (a) NOTICE TO STOCKHOLDERS.
 (b) NOTICE TO DIRECTORS.
 (c) AFFIDAVIT OF MAILING.
 (d) METHODS OF NOTICE.
 (e) NOTICE TO PERSON WITH WHOM COMMUNICATION IS UNLAWFUL.
 21.




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(f) NOTICE TO STOCKHOLDERS SHARING AN ADDRESS.
 ARTICLE 13
 AMENDMENTS
 13.1 BYLAW AMENDMENTS.
 ARTICLE 14
 LOANS TO EMPLOYEES
 14.1 LOANS TO EMPLOYEES.
 22.