title: Stereoselective reduction of carbonyl compounds with Actinomycete: purification and characterization of three alpha-keto ester reductases from Streptomyces avermitilis.
abstract: We achieved the purification of three alpha-keto ester reductases (Streptomyces avermitilis keto ester reductase, SAKERs-I, -II, and -III) from Streptomyces avermitilis NBRC14893 whole cells. The molecular masses of the native SAKERs-I, -II, and -III were estimated to be 72, 38, and 36 kDa, respectively, by gel filtration chromatography. The subunit molecular masses of SAKERs-I, -II, and -III were also estimated to be 32, 32, and 34 kDa, respectively, by SDS-polyacrylamide gel electrophoresis. The purified SAKERs-II and -III showed a reducing activity for alpha-keto esters (in particular, for ethyl pyruvate). SAKER-I showed a high reducing activity not only toward the alpha- and beta-keto esters, but also toward alpha-keto acid. The N-terminal region amino acid sequences of SAKERs-I, -II, and -III were identical to that of a putative oxidoreductase, SAV2750, a putative oxidoreductase, SAV1849, and a putative oxidoreductase, SAV4117, respectively, hypothetical proteins coded on the S. avermitilis genome.
authors.affiliation: Department of Life Science, Okayama University of Science, Okayama, Japan. ishihara@dls.ous.ac.jp
authors.forename: Kohji
authors.initials: K
authors.lastname: Ishihara
authors.forename: Chiaki
authors.initials: C
authors.lastname: Kato
authors.forename: Hitomi
authors.initials: H
authors.lastname: Yamaguchi
authors.forename: Rieko
authors.initials: R
authors.lastname: Iwai
authors.forename: Momoko
authors.initials: M
authors.lastname: Yoshida
authors.forename: Natsumi
authors.initials: N
authors.lastname: Ikeda
authors.forename: Hiroki
authors.initials: H
authors.lastname: Hamada
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Masuoka
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Nakajima
mesh_terms: D000595:Amino Acid Sequence; D004795:Enzyme Stability; D004952:Esters / Q000737:chemistry* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007659:Ketones / Q000737:chemistry*; D007700:Kinetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D013237:Stereoisomerism; D013302:Streptomyces / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004952:Esters; D007659:Ketones; D010088:Oxidoreductases