View source for 1xpk


==CRYSTAL STRUCTURE OF STAPHYLOCOCCUS AUREUS HMG-COA SYNTHASE WITH HMG-CoA AND WITH ACETOACETYL-COA AND ACETYLATED CYSTEINE==
<StructureSection load='1xpk' size='340' side='right'caption='[[1xpk]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1xpk]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1XPK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1XPK FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CAA:ACETOACETYL-COENZYME+A'>CAA</scene>, <scene name='pdbligand=HMG:3-HYDROXY-3-METHYLGLUTARYL-COENZYME+A'>HMG</scene>, <scene name='pdbligand=SCY:S-ACETYL-CYSTEINE'>SCY</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1xpk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1xpk OCA], [https://pdbe.org/1xpk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1xpk RCSB], [https://www.ebi.ac.uk/pdbsum/1xpk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1xpk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A0A0H3K1U2_STAAW A0A0H3K1U2_STAAW] 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/xp/1xpk_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1xpk ConSurf].
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== Publication Abstract from PubMed ==
The formation of carbon-carbon bonds via an acyl-enzyme intermediate plays a central role in fatty acid, polyketide, and isoprenoid biosynthesis. Uniquely among condensing enzymes, 3-hydroxy-3-methylglutaryl (HMG)-CoA synthase (HMGS) catalyzes the formation of a carbon-carbon bond by activating the methyl group of an acetylated cysteine. This reaction is essential in Gram-positive bacteria, and represents the first committed step in human cholesterol biosynthesis. Reaction kinetics, isotope exchange, and mass spectroscopy suggest surprisingly that HMGS is able to catalyze the "backwards" reaction in solution, where HMG-CoA is cleaved to form acetoacetyl-CoA (AcAc-CoA) and acetate. Here, we trap a complex of acetylated HMGS from Staphylococcus aureus and bound acetoacetyl-CoA by cryo-cooling enzyme crystals at three different times during the course of its back-reaction with its physiological product (HMG-CoA). This nonphysiological "backwards" reaction is used to understand the details of the physiological reaction with regards to individual residues involved in catalysis and substrate/product binding. The structures suggest that an active-site glutamic acid (Glu-79) acts as a general base both in the condensation between acetoacetyl-CoA and the acetylated enzyme, and the hydrolytic release of HMG-CoA from the enzyme. The ability to trap this enzyme-intermediate complex may suggest a role for protein dynamics and the interplay between protomers during the normal course of catalysis.

3-hydroxy-3-methylglutaryl-CoA synthase intermediate complex observed in "real-time".,Theisen MJ, Misra I, Saadat D, Campobasso N, Miziorko HM, Harrison DH Proc Natl Acad Sci U S A. 2004 Nov 23;101(47):16442-7. Epub 2004 Oct 21. PMID:15498869<ref>PMID:15498869</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 1xpk" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Staphylococcus aureus]]
[[Category: Campobasso N]]
[[Category: Harrison DHT]]
[[Category: Misra I]]
[[Category: Miziorko HM]]
[[Category: Saadat D]]
[[Category: Theisen MJ]]