title: Stenotrophomonas maltophilia OleC-Catalyzed ATP-Dependent Formation of Long-Chain Z-Olefins from 2-Alkyl-3-hydroxyalkanoic Acids.
abstract: The bacterial pathway of olefin biosynthesis starts with OleA catalyzed "head-to-head" condensation of two CoA-activated long-chain fatty acids to generate (R)-2-alkyl-3-ketoalkanoic acids. A subsequent OleD-catalyzed reduction generates (2R,3S)-2-alkyl-3-hydroxyalkanoic acids. We now show that the final step in the pathway is an OleC-catalyzed ATP-dependent decarboxylative dehydration to form the corresponding Z olefins. Higher kcat /Km values were seen for substrates with longer alkyl chains. All four stereoisomers of 2-hexyl-3-hydroxydecanoic acid were shown to be substrates, and GC-MS and NMR analyses confirmed that the product in each case was (Z)-pentadec-7-ene. LC-MS analysis supported the formation of AMP adduct as an intermediate. The enzymatic and stereochemical course of olefin biosynthesis from long-chain fatty acids by OleA, OleD and OleC is now established.
authors.affiliation: Department of Chemistry, Portland State University, Portland, OR, 97201-3203, USA.
authors.forename: Papireddy
authors.initials: P
authors.lastname: Kancharla
authors.affiliation: Department of Chemistry, Portland State University, Portland, OR, 97201-3203, USA.
authors.forename: Shilah A
authors.initials: SA
authors.lastname: Bonnett
authors.affiliation: Department of Chemistry, Portland State University, Portland, OR, 97201-3203, USA. reynoldk@pdx.edu.
authors.forename: Kevin A
authors.initials: KA
authors.lastname: Reynolds
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000475:Alkenes / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D055162:Biocatalysis; D003653:Decarboxylation; D003681:Dehydration; D053858:Metabolic Networks and Pathways; D009171:Mycolic Acids / Q000378:metabolism*; D020615:Stenotrophomonas maltophilia / Q000201:enzymology / Q000378:metabolism*
chemical_list: D000475:Alkenes; D001426:Bacterial Proteins; D009171:Mycolic Acids; D000255:Adenosine Triphosphate; C513423:2-hexyl-3-hydroxydecanoic acid
keywords: biosynthesis; enzyme catalysis; fatty acids; head-to-head condensation; olefins