This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Fazel, A M Articles by Jensen, R A Search for Related Content PubMed PubMed Citation Articles by Fazel, A M Articles by Jensen, R A

Aromatic aminotransferases in coryneform bacteria.

ABSTRACT

Species of coryneform bacteria (Corynebacterium glutamicum, Brevibacterium flavum, and B. ammoniagenes) are capable of transaminating all three of the aromatic pathway intermediates; prephenate, phenylpyruvate, and 4-hydroxy-phenylpyruvate. Two molecular species of aromatic aminotransferase (denoted aminotransferase I and aminotransferase II) were partially purified from C. glutamicum and B. flavum, whereas a single aromatic aminotransferase was isolated from B. ammoniagenes. In both C. glutamicum and B. flavum, aromatic aminotransferase I and aromatic aminotransferase II have molecular weights of about 155,000 and 260,000 respectively. The two aromatic aminotransferases from C. glutamicum and B. flavum, although exhibiting a similar spectrum of overlapping specificities, differ substantially in substrate preference. Pyridoxal-5'-phosphate is tightly associated with these aminotransferases, since little loss of activity was detected when partially purified enzyme preparations were assayed in the absence of exogenous pyridoxal-5'-phosphate. The aminotransferases are quite sensitive to inhibition by phenylhydrazine. This has practical application when assay of prephenate dehydratase is desired in the presence of aromatic aminotransferase activity since potentially trivial interference can be negated by selective phenylhydrazine inhibition of aromatic aminotransferase activity. At 0.1 mM concentrations of phenylhydrazine, 90% inhibitions of aminotransferase activities were achieved in partially purified preparations of B. flavum and C. glutamicum.

This article has been cited by other articles:

• Marienhagen, J., Kennerknecht, N., Sahm, H., Eggeling, L. (2005). Functional Analysis of All Aminotransferase Proteins Inferred from the Genome Sequence of Corynebacterium glutamicum. J. Bacteriol. 187: 7639-7646 [Abstract] [Full Text]