title: Biphenyl hydroxylation enhanced by an engineered o-xylene dioxygenase from Rhodococcus sp. strain DK17.
abstract: Hydroxylation of the non-growth substrate biphenyl by recombinant o-xylene dioxygenases from Rhodococcus sp. strain DK17 was studied through bioconversion experiments. The metabolites from the biphenyl hydroxylation by each enzyme were identified and quantified by gas chromatography-mass spectrometry. The L266F mutant enzyme produced much more 2-hydroxybiphenyl (2.43 vs. 0.1 μg/L) and 3-hydroxybiphenyl (1.97 vs. 0.03 μg/L) than the wild-type. Site-directed mutagenesis combined with structural and functional analyses indicated that hydrophobic interactions and shielding effects against water are important factors in the hydroxylation of biphenyl by the o-xylene dioxygenase. The residue at position 266 plays a key role in coordinating the reaction.
authors.affiliation: Department of Biology, Yonsei University, Seoul 120-749, South Korea.
authors.forename: Miyoun
authors.initials: M
authors.lastname: Yoo
authors.forename: Dockyu
authors.initials: D
authors.lastname: Kim
authors.forename: Gerben J
authors.initials: GJ
authors.lastname: Zylstra
authors.forename: Beom Sik
authors.initials: BS
authors.lastname: Kang
authors.forename: Eungbin
authors.initials: E
authors.lastname: Kim
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D001673:Biodegradation, Environmental; D001713:Biphenyl Compounds / Q000737:chemistry / Q000378:metabolism*; D049308:Dioxygenases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D006900:Hydroxylation; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D015202:Protein Engineering; D012240:Rhodococcus / Q000201:enzymology* / Q000235:genetics; D014992:Xylenes / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D001713:Biphenyl Compounds; D014992:Xylenes; D049308:Dioxygenases; C026114:2-xylene