6co6: Difference between revisions

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 <StructureSection load='6co6' size='340' side='right' caption='[[6co6]], [[Resolution|resolution]] 1.70&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[6co6]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6CO6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6CO6 FirstGlance]. <br>
+<table><tr><td colspan='2'>[[6co6]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Rhojr Rhojr]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6CO6 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6CO6 FirstGlance]. <br>
 </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
+<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">RHA1_ro04651 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=101510 RHOJR]), RHA1_ro04650 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=101510 RHOJR])</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=6co6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6co6 OCA], [http://pdbe.org/6co6 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6co6 RCSB], [http://www.ebi.ac.uk/pdbsum/6co6 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6co6 ProSAT]</span></td></tr>
 </table>
+<div style="background-color:#fffaf0;">
+== Publication Abstract from PubMed ==
+Mycobacterium tuberculosis (Mtb) grows on host-derived cholesterol during infection. IpdAB, found in all steroid-degrading bacteria and a determinant of pathogenicity, has been implicated in the hydrolysis of the last steroid ring. Phylogenetic analyses revealed that IpdAB orthologs form a clade of CoA transferases (CoTs). In a coupled assay with a thiolase, IpdAB transformed the cholesterol catabolite (R)-2-(2-carboxyethyl)-3-methyl-6-oxocyclohex-1-ene-1-carboxyl-CoA (COCHEA-CoA) and CoASH to 4-methyl-5-oxo-octanedioyl-CoA (MOODA-CoA) and acetyl-CoA with high specificity (kcat/Km = 5.8 +/- 0.8 x 10(4) M(-1)s(-1)). The structure of MOODA-CoA was consistent with IpdAB hydrolyzing COCHEA-CoA to a beta-keto-thioester, a thiolase substrate. Contrary to characterized CoTs, IpdAB exhibited no activity toward small CoA thioesters. Further, IpdAB lacks the catalytic glutamate residue that is conserved in the beta-subunit of characterized CoTs and a glutamyl-CoA intermediate was not trapped during turnover. By contrast, Glu105(A), conserved in the alpha-subunit of IpdAB, was essential for catalysis. A crystal structure of the IpdAB.COCHEA-CoA complex, solved to 1.4 A, revealed that Glu105(A) is positioned to act as a catalytic base. Upon titration with COCHEA-CoA, the E105A(A) variant accumulated a yellow-colored species (lambdamax = 310 nm; Kd = 0.4 +/- 0.2 muM) typical of beta-keto enolates. In the presence of D2O, IpdAB catalyzed the deuteration of COCHEA-CoA adjacent to the hydroxylation site at rates consistent with kcat Based on these data and additional IpdAB variants, we propose a retro-Claisen condensation-like mechanism for the IpdAB-mediated hydrolysis of COCHEA-CoA. This study expands the range of known reactions catalyzed by the CoT superfamily and provides mechanistic insight into an important determinant of Mtb pathogenesis.
+IpdAB, a virulence factor in Mycobacterium tuberculosis, is a cholesterol ring-cleaving hydrolase.,Crowe AM, Workman SD, Watanabe N, Worrall LJ, Strynadka NCJ, Eltis LD Proc Natl Acad Sci U S A. 2018 Mar 26. pii: 1717015115. doi:, 10.1073/pnas.1717015115. PMID:29581275<ref>PMID:29581275</ref>
+From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
+</div>
+<div class="pdbe-citations 6co6" style="background-color:#fffaf0;"></div>
+== References ==
+<references/>
 __TOC__
 </StructureSection>
+[[Category: Rhojr]]
 [[Category: Crow, A M]]
 [[Category: Eltis, L D]]