Characterization and role of the branched-chain aminotransferase (BcaT) isolated from Lactococcus lactis subsp. cremoris NCDO 763.

ABSTRACT: In Lactococcus lactis, which is widely used as a starter in the cheese industry, the first step of aromatic and branched-chain amino acid degradation is a transamination which is catalyzed by two major aminotransferases. We have previously purified and characterized biochemically and genetically the aromatic aminotransferase, AraT. In the present study, we purified and studied the second enzyme, the branched-chain aminotransferase, BcaT. We cloned and sequenced the corresponding gene and used a mutant, along with the luciferase gene as the reporter, to study the role of the enzyme in amino acid metabolism and to reveal the regulation of gene transcription. BcaT catalyzes transamination of the three branched-chain amino acids and methionine and belongs to class IV of the pyridoxal 5'-phosph

SUBMITTER: Yvon M 

PROVIDER: S-EPMC91865 | biostudies-literature | 2000 Feb

REPOSITORIES: biostudies-literature