Site-directed mutagenesis of two zinc-binding centers of the NADH-dependent phenylacetaldehyde reductase from styrene-assimilating Corynebacterium sp. strain ST-10.
Phenylacetaldehyde reductase (PAR) with a unique and wide substrate range from styrene-assimilating Corynebacterium sp. strain ST-10, which is a useful biocatalyst producing chiral alcohols, has been found to belong to a family of zinc-containing, long-chain alcohol dehydrogenases (ADHs) on the basis of the primary structure similarity. The enzyme contains 2 moles of zinc per mole of subunit. The amino acid residues assumed to be three catalytic and four structural zinc-binding ligands were characterized by site-directed mutagenesis, compared with other zinc-containing, long-chain ADHs. Sixteen PAR mutants gave measurable but rather low activities toward phenylacetaldehyde, n-hexyl aldehyde, and 2-heptanone, although they maintained the activities of 8 to 16% of that of wild-type PAR for an acetophenone substrate except that the D153N mutant showed quite low activity. The results suggested that the seven residues present in PAR were probably zinc-binding ligands, and mutation in these residues caused a change in activities for some substrates.
Wang
J C
JC
Department of Applied Chemistry and Biotechnology, Faculty of Engineering, Fukui University, Japan.
Sakakibara
M
M
Matsuda
M
M
Itoh
N
N
D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D003352:Corynebacterium / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D020058:Styrene / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
D020058:Styrene; D000429:Alcohol Oxidoreductases; C110191:phenylacetaldehyde reductase; D015032:Zinc