Schühle, KarolaKarolaSchühleGescher, JohannesJohannesGescherFeil, UlrichUlrichFeilPaul, MichaelMichaelPaulJahn, MartinaMartinaJahnSchägger, HermannHermannSchäggerFuchs, GeorgGeorgFuchs2023-02-102023-02-102003-08-15Journal of Bacteriology 185 (16): 4920-4929 (2003-08-15)http://hdl.handle.net/11420/14789In the denitrifying member of the β-Proteobacteria Thauera aromatica, the anaerobic metabolism of aromatic acids such as benzoate or 2-aminobenzoate is initiated by the formation of the coenzyme A (CoA) thioester, benzoyl-CoA and 2-aminobenzoyl-CoA, respectively. Both aromatic substrates were transformed to the acyl-CoA intermediate by a single CoA ligase (AMP forming) that preferentially acted on benzoate. This benzoate-CoA ligase was purified and characterized as a 57-kDa monomeric protein. Based on Vmax/Km, the specificity constant for 2-aminobenzoate was 15 times lower than that for benzoate; this may be the reason for the slower growth on 2-aminobenzoate. The benzoate-CoA ligase gene was cloned and sequenced and was found not to be part of the gene cluster encoding the general benzoyl-CoA pathway of anaerobic aromatic metabolism. Rather, it was located in a cluster of genes coding for a novel aerobic benzoate oxidation pathway. In line with this finding, the same CoA ligase was induced during aerobic growth with benzoate. A deletion mutant not only was unable to grow anaerobically on benzoate or 2-aminobenzoate, but also aerobic growth on benzoate was affected. This suggests that benzoate induces a single benzoate-CoA ligase. The product of benzoate activation, benzoyl-CoA, then acts as inducer of separate anaerobic or aerobic pathways of benzoyl-CoA, depending on whether oxygen is lacking or present.en0021-919320031649204929American Society for MicrobiologyBiowissenschaften, BiologieJournal Article10.1128/JB.185.16.4920-4929.200312897012Journal Article