Disease relevance of bkdR

• Mutations affecting bkdR could also be complemented by plasmids containing lrp of E. coli [1].
• The bkdR gene of Pseudomonas putida is required for expression of the bkd operon and encodes a protein related to Lrp of Escherichia coli [1].
• DNAs from several gram-negative bacteria hybridized to a probe containing bkdR, indicating the presence of bkdR-like genes in these organisms [2].

High impact information on bkdR

• Catabolite repression control by crc in 2xYT medium is mediated by posttranscriptional regulation of bkdR expression in Pseudomonas putida [3].
• 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 [4].
• Addition of glucose to the medium repressed expression of lacZ from a chromosomal bkdR-lacZ fusion, suggesting that catabolite repression of the bkd operon was the result of reduced expression of bkdR [5].
• P. putida JS110 and JS112, mutant strains which do not express any of the components of branched-chain keto acid dehydrogenase, were found to contain missense mutations in bkdR resulting in R40Q and T22I changes in the putative helix-turn-helix of BkdR [5].
• These mutations were complemented in trans by plasmids which contained intact bkdR [1].

Biological context of bkdR

• Therefore, the bkdR gene product must affect expression of the bkd operon and regulation must be positive [1].

Other interactions of bkdR

• This suggests that the mechanism of catabolite repression control in rich media by Crc involves posttranscriptional regulation of the bkdR message [3].

References