title: The enzymes with benzil reductase activity conserved from bacteria to mammals.
abstract: The diketone compound, benzil is reduced to (S)-benzoin with living Bacillus cereus cells. Recently, we isolated a gene responsible for benzil reduction, and Escherichia coli cells in which this gene was overexpressed transformed benzil to (S)-benzoin. Although this benzil reductase showed high identity to the short-chain dehydrogenase/reductase (SDR) family, enzymological features were unknown. Here, we demonstrated that many B. cereus strains had benzil reductase activity in vivo, and that the benzil reductases shared 94-100% amino acid identities. Recombinant B. cereus benzil reductase produced optically pure (S)-benzoin with NADPH in vitro, and the ketone group distal to a benzene ring was asymmetrically reduced. B. cereus benzil reductase showed 31% amino acid identity to the yeast open reading frame YIR036C protein and 28-30% to mammalian sepiapterin reductases, sharing the seven residues consensus for the SDR family. We isolated the genes encoding yeast YIR036C protein and gerbil sepiapterin reductase, and both recombinant proteins also reduced benzil to (S)-benzoin in vitro. Green fluorescent protein-tagged B. cereus benzil reductase distributed in the bipolar cytoplasm in B. cereus cells. Asymmetric reduction with B. cereus benzil reductase, yeast YIR036C protein and gerbil sepiapterin reductase will be utilized to produce important chiral compounds.
authors.affiliation: Department of Cell Engineering, Faculty of Engineering, Toyama University, 3190 Gofuku, 930-8555, Toyama, Japan.
authors.forename: Reiji
authors.initials: R
authors.lastname: Maruyama
authors.forename: Mikio
authors.initials: M
authors.lastname: Nishizawa
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Itoi
authors.forename: Seiji
authors.initials: S
authors.lastname: Ito
authors.forename: Masami
authors.initials: M
authors.lastname: Inoue
mesh_terms: D000429:Alcohol Oxidoreductases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001409:Bacillus cereus / Q000201:enzymology* / Q000235:genetics; D001573:Benzoin / Q000032:analysis; D016384:Consensus Sequence; D003593:Cytoplasm / Q000201:enzymology; D004926:Escherichia coli / Q000235:genetics; D019143:Evolution, Molecular; D005849:Gerbillinae; D066298:In Vitro Techniques; D008322:Mammals / Q000235:genetics*; D008969:Molecular Sequence Data; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity
chemical_list: D011993:Recombinant Fusion Proteins; D000429:Alcohol Oxidoreductases; C446000:benzil reductase; C022630:sepiapterin reductase; D001573:Benzoin