title: Characterization of four Rhodococcus alcohol dehydrogenase genes responsible for the oxidation of aromatic alcohols.
abstract: Four genes were isolated and characterized for alcohol dehydrogenases (ADHs) catalyzing the oxidation of aromatic alcohols such as benzyl alcohol to their corresponding aldehydes, one from o-xylene-degrading Rhodococcus opacus TKN14 and the other three from n-alkane-degrading Rhodococcus erythropolis PR4. Various aromatic alcohols were bioconverted to their corresponding carboxylic acids using Escherichia coli cells expressing each of the four ADH genes together with an aromatic aldehyde dehydrogenase gene (phnN) from Sphingomonas sp. strain 14DN61. The ADH gene (designated adhA) from strain TKN14 had the ability to biotransform a wide variety of aromatic alcohols, i.e., 2-hydroxymethyl-6-methylnaphthalene, 2-hydroxymethylnaphthalene, xylene-alpha,alpha'-diol, 3-chlorobenzyl alcohol, and vanillyl alcohol, in addition to benzyl alcohol with or without a hydroxyl, methyl, or methoxy substitution. In contrast, the three ADH genes of strain PR4 (designated adhA, adhB, and adhC) exhibited lower ability to degrade these alcohols: these genes stimulated the conversion of the alcohol substrates by only threefold or less of the control value. One exception was the conversion of 3-methoxybenzyl alcohol, which was stimulated sevenfold by adhB. A phylogenetic analysis of the amino acid sequences of these four enzymes indicated that they differed from other Zn-dependent ADHs.
authors.affiliation: Marine Biotechnology Institute, 3-75-1 Heita, Kamaishi-shi, 026-0001, Iwate, Japan.
authors.forename: Xue
authors.initials: X
authors.lastname: Peng
authors.forename: Hironori
authors.initials: H
authors.lastname: Taki
authors.forename: Syoko
authors.initials: S
authors.lastname: Komukai
authors.forename: Mitsuo
authors.initials: M
authors.lastname: Sekine
authors.forename: Kaneo
authors.initials: K
authors.lastname: Kanoh
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Kasai
authors.forename: Seon-Kang
authors.initials: SK
authors.lastname: Choi
authors.forename: Seiha
authors.initials: S
authors.lastname: Omata
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tanikawa
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Harayama
authors.forename: Norihiko
authors.initials: N
authors.lastname: Misawa
mesh_terms: D000426:Alcohol Dehydrogenase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019905:Benzyl Alcohol / Q000378:metabolism*; D001711:Biotransformation; D002264:Carboxylic Acids / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D008401:Gas Chromatography-Mass Spectrometry; D008954:Models, Biological; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012240:Rhodococcus / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D002264:Carboxylic Acids; D000426:Alcohol Dehydrogenase; D019905:Benzyl Alcohol