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- Document 0070
- DOCN M9470070
- TI Alternative native flap conformation revealed by 2.3 A resolution
- structure of SIV proteinase.
- DT 9409
- AU Wilderspin AF; Sugrue RJ; Department of Crystallography, Birkbeck
- College, London, England.
- SO J Mol Biol. 1994 May 27;239(1):97-103. Unique Identifier : AIDSLINE
- MED/94254094
- AB A large conformational change is observed between HIV-1 proteinase in
- the ligand-free state and in complexes with transition-state inhibitors.
- Crystal structures of this enzyme have either the flaps open for the
- native or ligand-free enzyme or the flaps closed for peptidomimetic
- ligand-bound enzyme. We describe the structure of native recombinant SIV
- proteinase which like other retroviral proteinases crystallizes as a
- perfect 2-fold symmetric dimer but in a different crystal packing
- arrangement. In contrast to HIV-1 PR we show that SIV proteinase in the
- ligand-free state adopts the closed flaps conformation, demonstrating
- that ligand binding is not a prerequisite for the closed flaps
- conformation. The catalytic water was clearly observed between the two
- aspartates which were not perfectly co-planar, and in this structure the
- active site cleft is more restricted than for either inhibitor bound or
- ligand-free HIV-1 proteinase. Accommodation of two bulkier side-chains
- in the simian enzyme core has resulted in a more exposed N terminus than
- for HIV-1 PR which we predict could enhance autocatalytic cleavage at
- the N terminus.
- DE Amino Acid Sequence Aspartic Proteinases/*CHEMISTRY/GENETICS Binding
- Sites HIV Protease/GENETICS Models, Molecular Molecular Sequence Data
- Molecular Structure *Protein Conformation Sequence Alignment Support,
- Non-U.S. Gov't SIV/*ENZYMOLOGY JOURNAL ARTICLE
-
- SOURCE: National Library of Medicine. NOTICE: This material may be
- protected by Copyright Law (Title 17, U.S.Code).
-
-