title: Regulation of the homologous two-component systems KvgAS and KvhAS in Klebsiella pneumoniae CG43.
abstract: In Klebsiella pneumoniae CG43, deletion of the sensor gene kvgS reduced the kvgAS expression in M9 medium with 0.2 mM paraquat, 0.2 mM 2,2-dihydropyridyl, or 300 mM NaCl. This result shows an autoregulatory role of KvgS and a stress-responsive expression of the two-component system (2CS). The kvgS deletion also appeared to decrease the expression of kvhAS, paralogous genes of kvgAS. Additionally, measurements of the promoter activity in kvgA(-) mutant revealed that KvgA is probably an activator for the expression of kvgAS and kvhAS. The subsequent electrophoretic mobility shift assay, indicating a specific binding of the recombinant KvgA to the putative promoters P(kvgAS) and P(kvhAS), also supported an interacting regulation between the 2CSs. In P(kvgAS) and P(kvhAS), the presence of RpoS binding elements suggested an RpoS-dependent regulation. Nevertheless, the rpoS deletion reduced the expression of kvgAS but increased that of kvhAS. Moreover, the kvgA deletion reduced the expression of katG and sodC. The overexpression of KvhA altered the susceptibility to fosfomycin and an increasing activity of UDP-N-acetylglucosamine enolpyruvyl transferase, the target protein of fosfomycin, which suggesting a regulation by KvhA. Taken together, these indicated that the two 2CSs probably belong to different regulatory circuits of the RpoS regulon.
authors.affiliation: Department of Biological Science and Technology, National Chiao Tung University, 75 Po-Ai Street, Hsin Chu 30050, Taiwan, Republic of China.
authors.forename: Ching-Ting
authors.initials: CT
authors.lastname: Lin
authors.forename: Hwei-Ling
authors.initials: HL
authors.lastname: Peng
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000502:physiology*; D002228:Carbenicillin / Q000494:pharmacology; D002512:Cephalothin / Q000494:pharmacology; D024202:Electrophoretic Mobility Shift Assay; D005578:Fosfomycin / Q000494:pharmacology; D017353:Gene Deletion; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000502:physiology*; D010878:Piperacillin / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000235:genetics; D011494:Protein Kinases / Q000235:genetics*; D012808:Sigma Factor / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C069567:sigma factor KatF protein, Bacteria; D005578:Fosfomycin; D011494:Protein Kinases; D000071677:Histidine Kinase; D002228:Carbenicillin; D002512:Cephalothin; D010878:Piperacillin