title: Expression and characterization of the genes encoding azoreductases from Bacillus subtilis and Geobacillus stearothermophilus.
abstract: Azoreductases have been characterized as enzymes that can decolorize azo dyes by reducing azo groups. In this study, genes encoding proteins having homology with the azoreductase gene of Bacillus sp. OY1-2 were obtained from Bacillus subtilis ATCC6633, B. subtilis ISW1214, and Geobacillus stearotherophilus IFO13737 by polymerase chain reaction. All three genes encoded proteins with 174 amino acids. The deduced amino acid sequences of azoreductase homologs from B. subtilis ISW1214, B. subtilis ATCC6633, and G. stearotherophilus IFO13737 showed similarity of 53.3, 53.9, and 53.3% respectively to that of Bacillus sp. OY1-2. All three genes were expressed in Escherichia coli, and were characterized as having the decolorizing activity of azo dyes in a beta-NADPH dependent manner. The transformation of several azo dyes into colorless compounds by recombinant enzymes was demonstrated to have distinct substrate specificity from that of azoreductase from Bacillus sp. OY1-2.
authors.affiliation: Department of Environmental Health, Osaka Prefectural Institute of Public Health, Osaka 537-0025, Japan.
authors.forename: Wataru
authors.initials: W
authors.lastname: Sugiura
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yoda
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsuba
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Suzuki
mesh_terms: D000595:Amino Acid Sequence; D001391:Azo Compounds / Q000378:metabolism*; D001412:Bacillus subtilis / Q000201:enzymology*; D003001:Cloning, Molecular; D004396:Coloring Agents / Q000378:metabolism*; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D009249:NADP / Q000378:metabolism; D009601:Nitroreductases; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D011994:Recombinant Proteins; D009249:NADP; D009247:NADH, NADPH Oxidoreductases; D009601:Nitroreductases; C021106:azoreductase