Characterization of an Escherichia coli aromatic hydroxylase with a broad substrate range.
The hpaB gene encoding an aromatic hydroxylase of Escherichia coli ATCC 11105, a penicillin G acylase-producing strain, has been cloned and expressed in E. coli K-12. This gene was located near the pacA gene coding for penicillin G acylase. The hydroxylase has a molecular mass of 59,000 Da, uses NADH as a cosubstrate, and was tentatively classified as a 4-hydroxyphenylacetic acid hydroxylase, albeit it exhibited a rather broad substrate specificity acting on different monohydric and dihydric phenols. E. coli W, C, and B as well as Klebsiella pneumoniae M5a1 and Kluyvera citrophila ATCC 21285 (a penicillin G acylase-producing strain) but not E. coli K-12 contained sequences homologous to hpaB. Our results support the hypothesis that hpaB is a component of the 4-hydroxyphenylacetic acid degradative pathway of E. coli W.
Prieto
M A
MA
Unidad de Genética Bacteriana, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Cientificas, Velázquez, Madrid.
Perez-Aranda
A
A
Garcia
J L
JL
D015139:Blotting, Southern; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D010399:Penicillin Amidase / Q000235:genetics; D010400:Penicillin G; D010636:Phenols / Q000378:metabolism; D010648:Phenylacetates / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D013045:Species Specificity; D013379:Substrate Specificity
D010636:Phenols; D010648:Phenylacetates; D011994:Recombinant Proteins; C008070:4-hydroxyphenylacetic acid; D006899:Mixed Function Oxygenases; C026252:4-hydroxyphenylacetate 3-monooxygenase; D010399:Penicillin Amidase; D010400:Penicillin G