4ku3: Difference between revisions
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<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=4ku3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ku3 OCA], [http://pdbe.org/4ku3 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4ku3 RCSB], [http://www.ebi.ac.uk/pdbsum/4ku3 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4ku3 ProSAT]</span></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=4ku3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ku3 OCA], [http://pdbe.org/4ku3 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4ku3 RCSB], [http://www.ebi.ac.uk/pdbsum/4ku3 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4ku3 ProSAT]</span></td></tr> | ||
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== Publication Abstract from PubMed == | |||
Phylogenetically diverse microbes that produce long chain, olefinic hydrocarbons have received much attention as possible sources of renewable energy biocatalysts. One enzyme that is critical for this process is OleA, a thiolase superfamily enzyme that condenses two fatty acyl-CoA substrates to produce a beta-ketoacid product and initiates the biosynthesis of long chain olefins in bacteria. Thiolases typically utilize a ping-pong mechanism centered on an active site cysteine residue. Reaction with the first substrate produces a covalent cysteine-thioester tethered acyl group that is transferred to the second substrate through formation of a carbon-carbon bond. Although the basics of thiolase chemistry are precedented, the mechanism by which OleA accommodates two substrates with extended carbon chains and a coenzyme moiety-unusual for a thiolase-are unknown. Gaining insights into this process could enable manipulation of the system for large scale olefin production with hydrocarbon chains lengths equivalent to those of fossil fuels. In this study, mutagenesis of the active site cysteine in Xanthomonas campestris OleA (Cys143) enabled trapping of two catalytically relevant species in crystals. In the resulting structures, long chain alkyl groups (C12 and C14) and phosphopantetheinate define three substrate channels in a T-shaped configuration, explaining how OleA coordinates its two substrates and product. The C143A OleA co-crystal structure possesses a single bound acyl-CoA representing the Michaelis complex with the first substrate, whereas the C143S co-crystal structure contains both acyl-CoA and fatty acid, defining how a second substrate binds to the acyl-enzyme intermediate. An active site glutamate (Glubeta117) is positioned to deprotonate bound acyl-CoA and initiate carbon-carbon bond formation. | |||
Substrate Trapping in Crystals of the Thiolase OleA Identifies Three Channels That Enable Long Chain Olefin Biosynthesis.,Goblirsch BR, Jensen MR, Mohamed FA, Wackett LP, Wilmot CM J Biol Chem. 2016 Dec 23;291(52):26698-26706. doi: 10.1074/jbc.M116.760892. Epub , 2016 Nov 4. PMID:27815501<ref>PMID:27815501</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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== References == | |||
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