In:
European Journal of Biochemistry, Wiley, Vol. 227, No. 1-2 ( 1995-01), p. 161-168
Abstract:
A new variant of aerobic benzoate degradation has been found in a denitrifying bacterium in which benzoyl‐CoA is the first intermediate [Altenschmidt, U., Oswald, B., Steiner, E., Herrmann, H. & Fuchs, G. (1993) New aerobic benzoate oxidation pathway via benzoyl‐coenzyme A and 3‐hydroxybenzoyl‐coenzyme A in a denitrifying Pseudomonas sp, J. Bacteriol. 175 , 4851–4858)]. The initial reaction is catalyzed by benzoate‐CoA ligase (AMP‐forming), converting benzoate into benzoyl‐CoA. The next step is 3‐hydroxylation of benzoyl‐CoA to 3‐hydroxybenzoyl‐CoA catalyzed by a flavin‐nucleotide‐dependent monooxygenase, benzoyl‐CoA 3‐monooxygenase. This novel enzyme has been purified and studied. It is specific for NADPH and requires the presence of a flavin nucleotide for activity; both FAD or FMN function similarly well as cofactor. Only benzoyl‐CoA, but not benzoate, is hydroxylated. The protein is a monomer of M r 65 000 and is induced when cells are grown aerobically with benzoate. 3‐Hydroxybenzoyl‐CoA is further hydroxylated para to the hydroxyl group affording 2,5‐dihydroxybenzoate (gentisate). This reaction requires another monooxygenase, 3‐hydroxybenzoyl‐CoA 6‐monooxygenase, which is unspecific with respect to the pyridine nucleotide. Cells contain a second 6‐monooxygenase activity which acts on free 3‐hydroxybenzoate. Based on these and other data, the outlines of the new aerobic benzoate pathway have been deduced. The proposed intermediates are benzoyl‐CoA, 3‐hydroxybenzoyl‐CoA, gentisate, maleylpyruvate, fumarylpyruvate and fumarate plus pyruvate.
Type of Medium:
Online Resource
ISSN:
0014-2956
,
1432-1033
DOI:
10.1111/ejb.1995.227.issue-1-2
DOI:
10.1111/j.1432-1033.1995.tb20372.x
Language:
English
Publisher:
Wiley
Publication Date:
1995
detail.hit.zdb_id:
1398347-7
detail.hit.zdb_id:
2172518-4
SSG:
12
Permalink