In vitro transcriptional studies of the bkd operon of Pseudomonas putida: L-branched-chain amino acids and D-leucine are the inducers.

ABSTRACT: BkdR is the transcriptional activator of the bkd operon, which encodes the four proteins of the branched-chain keto acid dehydrogenase multienzyme complex of Pseudomonas putida. In this study, hydroxyl radical footprinting revealed that BkdR bound to only one face of DNA over the same region identified in DNase I protection assays. Deletions of even a few bases in the 5' region of the BkdR-binding site greatly reduced transcription, confirming that the entire protected region is necessary for transcription. In vitro transcription of the bkd operon was obtained by using a vector containing the bkdR-bkdA1 intergenic region plus the putative rho-independent terminator of the bkd operon. Substrate DNA, BkdR, and any of the L-branched-chain amino acids or D-leucine was required for transcriptio

SUBMITTER: Madhusudhan KT 

PROVIDER: S-EPMC93734 | biostudies-literature | 1999 May

REPOSITORIES: biostudies-literature