title: Identification of residues important for the catalysis, structure maintenance, and substrate specificity of yeast 3-hydroxyacyl-CoA dehydratase Phs1.
abstract: Yeast Phs1 is a 3-hydroxyacyl-CoA dehydratase involved in very long-chain fatty acid elongation. In the present study, we biochemically characterized Phs1 mutants with Ala-substitution at each of seven highly conserved amino-acid residues. All mutants exhibited reduced Phs1 activity. The E60A, Q79A, and R141A mutants were sensitive to digitonin, indicative of their reduced structural integrity. The fatty acid elongation cycle was greatly inhibited in the R83A, R141A, and G152A mutant membranes. The enzyme kinetics study implicated the direct involvement of the Arg83 and Gly152 residues in the catalytic process. The E60A mutation was found to affect the substrate specificity.
authors: Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan.
authors: Tomoyo
authors: T
authors: Yazawa
authors: Tatsuro
authors: T
authors: Naganuma
authors: Maki
authors: M
authors: Yamagata
authors: Akio
authors: A
authors: Kihara
mesh_terms: D020816:Amino Acid Motifs; D019943:Amino Acid Substitution; D055162:Biocatalysis; D020134:Catalytic Domain; D005227:Fatty Acids / Q000737:chemistry* / Q000378:metabolism; D006836:Hydro-Lyases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D009154:Mutation; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity; D014162:Transfection
chemical_list: D005227:Fatty Acids; D029701:Saccharomyces cerevisiae Proteins; D006836:Hydro-Lyases; C529568:Phs1 protein, S cerevisiae