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Similarities between the antABC-encoded anthranilate dioxygenase and the benABC-encoded benzoate dioxygenase of Acinetobacter sp. strain ADP1.
- Source :
-
Journal of bacteriology [J Bacteriol] 1998 Sep; Vol. 180 (17), pp. 4466-74. - Publication Year :
- 1998
-
Abstract
- Acinetobacter sp. strain ADP1 can use benzoate or anthranilate as a sole carbon source. These structurally similar compounds are independently converted to catechol, allowing further degradation to proceed via the beta-ketoadipate pathway. In this study, the first step in anthranilate catabolism was characterized. A mutant unable to grow on anthranilate, ACN26, was selected. The sequence of a wild-type DNA fragment that restored growth revealed the antABC genes, encoding 54-, 19-, and 39-kDa proteins, respectively. The deduced AntABC sequences were homologous to those of class IB multicomponent aromatic ring-dihydroxylating enzymes, including the dioxygenase that initiates benzoate catabolism. Expression of antABC in Escherichia coli, a bacterium that normally does not degrade anthranilate, enabled the conversion of anthranilate to catechol. Unlike benzoate dioxygenase (BenABC), anthranilate dioxygenase (AntABC) catalyzed catechol formation without requiring a dehydrogenase. In Acinetobacter mutants, benC substituted for antC during growth on anthranilate, suggesting relatively broad substrate specificity of the BenC reductase, which transfers electrons from NADH to the terminal oxygenase. In contrast, the benAB genes did not substitute for antAB. An antA point mutation in ACN26 prevented anthranilate degradation, and this mutation was independent of a mucK mutation in the same strain that prevented exogenous muconate degradation. Anthranilate induced expression of antA, although no associated transcriptional regulators were identified. Disruption of three open reading frames in the immediate vicinity of antABC did not prevent the use of anthranilate as a sole carbon source. The antABC genes were mapped on the ADP1 chromosome and were not linked to the two known supraoperonic gene clusters involved in aromatic compound degradation.
- Subjects :
- Acinetobacter growth & development
Amino Acid Sequence
Catechols metabolism
Chromosomes, Bacterial
Mixed Function Oxygenases metabolism
Mutation
Open Reading Frames
Oxygenases metabolism
Sequence Homology, Amino Acid
Sorbic Acid analogs & derivatives
Sorbic Acid metabolism
ortho-Aminobenzoates metabolism
Acinetobacter enzymology
Mixed Function Oxygenases genetics
Oxygenases genetics
Subjects
Details
- Language :
- English
- ISSN :
- 0021-9193
- Volume :
- 180
- Issue :
- 17
- Database :
- MEDLINE
- Journal :
- Journal of bacteriology
- Publication Type :
- Academic Journal
- Accession number :
- 9721284
- Full Text :
- https://doi.org/10.1128/JB.180.17.4466-4474.1998