1l1e

<table><tr><td colspan='2'>[[1l1e]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_tuberculosis"_(zopf_1883)_klein_1884 "bacillus tuberculosis" (zopf 1883) klein 1884]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1L1E OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1L1E FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CO3:CARBONATE+ION'>CO3</scene>, <scene name='pdbligand=SAH:S-ADENOSYL-L-HOMOCYSTEINE'>SAH</scene></td></tr>

<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">pcaA ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=1773 "Bacillus tuberculosis" (Zopf 1883) Klein 1884])</td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Cyclopropane-fatty-acyl-phospholipid_synthase Cyclopropane-fatty-acyl-phospholipid synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.1.1.79 2.1.1.79] </span></td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1l1e FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1l1e OCA], [http://pdbe.org/1l1e PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1l1e RCSB], [http://www.ebi.ac.uk/pdbsum/1l1e PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1l1e ProSAT], [http://www.topsan.org/Proteins/TBSGC/1l1e TOPSAN]</span></td></tr>

[[http://www.uniprot.org/uniprot/CMAS3_MYCTO CMAS3_MYCTO]] Involved in the phagosome maturation block (PMB). Catalyzes the conversion of a double bond to a cyclopropane ring at the proximal position of an alpha mycolic acid via the transfer of a methylene group from S-adenosyl-L-methionine. It can use cis, cis 11,14-eicosadienoic acid and linoelaidic acid as substrate. Cyclopropanated mycolic acids are key factors participating in cell envelope permeability, host immunomodulation and persistence (By similarity).

<div style="background-color:#fffaf0;">

== 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>

</div>

<div class="pdbe-citations 1l1e" style="background-color:#fffaf0;"></div>

[[Category: Cyclopropane-fatty-acyl-phospholipid synthase]]

[[Category: Glickman, M S]]

[[Category: Huang, C C]]

[[Category: Jacobs, W R]]

[[Category: Sacchettini, J C]]

[[Category: Smith, C V]]

[[Category: Structural genomic]]

[[Category: Alpha/beta]]

[[Category: Methyltransferase]]

[[Category: Transferase]]