1sip

<StructureSection load='1sip' size='340' side='right' caption='[[1sip]], [[Resolution|resolution]] 2.30&Aring;' scene=''>

<table><tr><td colspan='2'>[[1sip]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Civ Civ]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SIP OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1SIP FirstGlance]. <br>

</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1sip FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1sip OCA], [http://pdbe.org/1sip PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1sip RCSB], [http://www.ebi.ac.uk/pdbsum/1sip PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1sip ProSAT]</span></td></tr>

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== Publication Abstract from PubMed ==

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.

Alternative native flap conformation revealed by 2.3 A resolution structure of SIV proteinase.,Wilderspin AF, Sugrue RJ J Mol Biol. 1994 May 27;239(1):97-103. PMID:8196050<ref>PMID:8196050</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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<div class="pdbe-citations 1sip" style="background-color:#fffaf0;"></div>

*[[Immunodeficiency virus protease|Immunodeficiency virus protease]]

[[Category: Civ]]

[[Category: Wilderspin, A F]]