title: Site-directed mutagenesis of a fatty acid elongase ELO-like condensing enzyme.
abstract: The condensation step of fatty acid elongation is the addition of a C2 unit from malonyl-CoA to an acyl primer catalyzed by one of two families of enzymes, the 3-ketoacyl-CoA synthases and the ELO-like condensing enzymes. 3-Ketoacyl-CoA synthases use a Claisen-like reaction mechanism while the mechanism of the ELO-catalyzed condensation reaction is unknown. We have used site-directed mutagenesis of Dictyostelium discoideum EloA to identify residues important to catalytic activity and/or structure. Mutation of highly conserved polar residues to alanine resulted in an inactive enzyme strongly suggesting that these residues play a role in the condensation reaction.
authors.affiliation: Department of Chemistry and Chemical Biology, Indiana University - Purdue University Indianapolis, Indianapolis, IN 46202, USA.
authors.forename: Selene
authors.initials: S
authors.lastname: Hernandez-Buquer
authors.forename: Brenda J
authors.initials: BJ
authors.lastname: Blacklock
mesh_terms: D000123:Acetyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000409:Alanine / Q000737:chemistry / Q000235:genetics; D000595:Amino Acid Sequence; D020134:Catalytic Domain; D004023:Dictyostelium / Q000201:enzymology; D000081031:Fatty Acid Elongases; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed
chemical_list: D000123:Acetyltransferases; D000081031:Fatty Acid Elongases; D000409:Alanine
keywords: 3-ketoacylCoA synthase; CoA; Condensing enzyme; ELO; ER; Fatty acid elongation; GC/MS; KCS; VLCFA; coenzyme A; endoplasmic reticulum; gas chromatography/mass spectrometry; very long chain fatty acids