title: Characterization of methylhydroquinone-metabolizing oxygenase genes encoded on plasmid in Burkholderia sp. NF100.
abstract: Methylhydroquinone is an intermediate in the degradation of fenitrothion by Burkholderia sp. NF100. The catabolic gene (mhq) for methylhydroquinone degradation encoded on the plasmid pNF1 in the strain was cloned and sequenced. The mhq clone contained two ORFs, mhqA and mhqB, of which the deduced amino acid sequence shared significant homology with NAD(P)H-dependent flavoprotein monooxygenases and extradiol dioxygenases, respectively. Parts of the consensus sequences of the monooxygenase gene and dioxygenase gene have been identified in MhqA and MhqB from strain NF100, respectively. MhqA was overexpressed in Escherichia coli, and partially purified MhqA catalyzed the NADPH-dependent hydroxylation of methylhydroquinone. MhqB was also overexpressed in E. coli, and the purified enzyme showed an extradiol ring cleavage activity toward 3-methylcatechol but a very low activity was observed toward 4-methylcatechol.
authors.affiliation: United Graduate School of Agricultural Science, Gifu University, 1-1 Yanagido, Gifu city, Japan.
authors.forename: Kanako
authors.initials: K
authors.lastname: Tago
authors.forename: Junichi
authors.initials: J
authors.lastname: Sato
authors.forename: Hideaki
authors.initials: H
authors.lastname: Takesa
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kawagishi
authors.forename: Masahito
authors.initials: M
authors.lastname: Hayatsu
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D001673:Biodegradation, Environmental; D019117:Burkholderia / Q000201:enzymology / Q000235:genetics*; D003001:Cloning, Molecular; D049308:Dioxygenases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005278:Fenitrothion / Q000378:metabolism; D006873:Hydroquinones / Q000737:chemistry / Q000378:metabolism*; D007306:Insecticides / Q000378:metabolism; D008969:Molecular Sequence Data; D010957:Plasmids / Q000235:genetics*; D013379:Substrate Specificity
chemical_list: D001426:Bacterial Proteins; D006873:Hydroquinones; D007306:Insecticides; C062397:2-methyl-1,4-hydroquinone; D049308:Dioxygenases; D005278:Fenitrothion