View source for 1kpg


==Crystal Structure of mycolic acid cyclopropane synthase CmaA1 complexed with SAH and CTAB==
<StructureSection load='1kpg' size='340' side='right'caption='[[1kpg]], [[Resolution|resolution]] 2.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1kpg]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis Mycobacterium tuberculosis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1KPG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1KPG 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=16A:CETYL-TRIMETHYL-AMMONIUM'>16A</scene>, <scene name='pdbligand=CO3:CARBONATE+ION'>CO3</scene>, <scene name='pdbligand=MSE:SELENOMETHIONINE'>MSE</scene>, <scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</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=1kpg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1kpg OCA], [https://pdbe.org/1kpg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1kpg RCSB], [https://www.ebi.ac.uk/pdbsum/1kpg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1kpg ProSAT]</span></td></tr>
</table>
== 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/kp/1kpg_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=1kpg ConSurf].
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== Publication Abstract from PubMed ==
Mycolic acids are major components of the cell wall of Mycobacterium tuberculosis. Several studies indicate that functional groups in the acyl chain of mycolic acids are important for pathogenesis and persistence. There are at least three mycolic acid cyclopropane synthases (PcaA, CmaA1, and CmaA2) that are responsible for these site-specific modifications of mycolic acids. To derive information on the specificity and enzyme mechanism of the family of proteins, the crystal structures of CmaA1, CmaA2, and PcaA were solved to 2-, 2-, and 2.65-A resolution, respectively. All three enzymes have a seven-stranded alpha/beta fold similar to other methyltransferases with the location and interactions with the cofactor S-adenosyl-l-methionine conserved. The structures of the ternary complexes demonstrate the position of the mycolic acid substrate binding site. Close examination of the active site reveals electron density that we believe represents a bicarbonate ion. The structures support the hypothesis that these enzymes catalyze methyl transfer via a carbocation mechanism in which the bicarbonate ion acts as a general base. In addition, comparison of the enzyme structures reveals a possible mechanism for substrate specificity. These structures provide a foundation for rational-drug design, which may lead to the development of new inhibitors effective against persistent bacteria.

Crystal structures of mycolic acid cyclopropane synthases from Mycobacterium tuberculosis.,Huang CC, Smith CV, Glickman MS, Jacobs WR Jr, Sacchettini JC J Biol Chem. 2002 Mar 29;277(13):11559-69. Epub 2001 Dec 26. PMID:11756461<ref>PMID:11756461</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Fatty acid synthase 3D structures|Fatty acid synthase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mycobacterium tuberculosis]]
[[Category: Glickman MS]]
[[Category: Huang C-C]]
[[Category: Jacobs Jr WR]]
[[Category: Sacchettini JC]]
[[Category: Smith CV]]