Characterization of the genes encoding a receptor-like histidine kinase and a cognate response regulator from a biphenyl/polychlorobiphenyl-degrading bacterium, Rhodococcus sp. strain M5

Abstract

We report the cloning, sequence, and expression of the bpdS and bpdT genes from Rhodococcus sp. strain M5, which are believed to encode the first two-component signal transduction system in the genus Rhodococcus, which potentially regulates biphenyl/polychlorobiphenyl metabolism in M5. BpdT has a typical responses regulator sequence (209 amino acids; 23 kDa), whereas BpdS, the predicted histidine kinase component, is an unusually large transmembrane protein (1,576 amino acids; 170 kDa) that contains ATP-binding and leucinerich repeat motifs and some conserved residues of protein kinases. Expression of bpdST, like that of the bpdC1C2BADE degradative operon, is inducible by biphenyl.

Versatile Transcription of Biphenyl Catabolic bphOperon in Pseudomonas pseudoalcaligenes KF707

“…These bpd genes are inducibly transcribed by biphenyl. In this system, BpdS and BpdT function as a sensor histidine kinase and a response regulator, respectively (19). Here we report the versatile transcription of the KF707 bph gene cluster, indicating that the ORF0 protein is an activator and is absolutely involved in the expressions of its own orf0 and bphX0X1X2X3D and that at least six transcriptional initiation sites are present in the KF707 bph gene cluster.…”

The GAF-Like-Domain-Containing Transcriptional Regulator DfdR Is a Sensor Protein for Dibenzofuran and Several Hydrophobic Aromatic Compounds

“…Transcriptional regulation of metabolic pathways for toluene (tod) and styrene (sty) is involved in the TodST and StySR TCST systems, respectively (27,38), and the ligand for the TCST system is the primary substrate of the target pathway. The biphenyl catabolic gene regulator in high-GϩC-content gram-positive Rhodococcus species is a TCST system, and biphenyl, which contains two aromatic rings, is an effector (4,26,48). Genes for a member of the TCST system were detected downstream of the biphenyl catabolic pathway genes of three Rhodococcus strains and encoded a particularly large histidine kinase component (BphS or BpdS) and a re- a Assays were carried out with the R. erythropolis JCM 2892 transformant containing pRKluxP A -dfdR, which contains a 481-bp dfdA1 promoter region and dfdR with its own promoter.…”

“…The transcriptional regulation system in high-GϩC-content gram-positive Rhodococcus strains has a different regulatory mechanism for bph gene expression. Biphenyl-utilizing Rhodococcus strains use the twocomponent signal transduction (TCST) system (4,26,48), and the primary substrate biphenyl acts as an effector for transcriptional activation of the bph gene cluster in Rhodococcus sp. strain RHA1 (48).…”

Biochemical and genetic bases of microbial degradation of polychlorinated biphenyls(PCBs).

“…The bph operon in Gram-positive Rhodococcus sp. M5, bpdC1C2BADEF, was suggested as being regulated by a two-component signal transduction system of bpdS and bpdT (Labbe et al, 1997). In this system, BpdS and BpdT seem to function as a sensor histidine kinase and a response regulator, respectively.…”