In E. coliK-12, two component systems (TCSs) sense and respond to changes in environmental conditions. Typically, a membrane associated sensor kinase autophosphorylates in response to an environmental signal. The sensor kinase then transfers a phosphoryl group to a response regulator (RR) which thus activated, effects a response. The majority of RRs in E. coli are transcription factors. The BaeS and BaeR proteins are respectively, the sensor kinase and response regulator of the E. coli BaeSR two-component system. The BaeSR TCS induces expression of spy in response to envelope stresses such as spheroblast formation or misfolded pilus subunits, leading to the suggestion that the BaeSR TCS is an envelope stress response pathway. baeS and baeR form an operon with the multidrug resistance cluster mdtABCD and BaeR binds to and stimulates the transcriptional activity of the mdtA promoter. Overexpression of BaeR results in increased resistance to novobiocin and deoxycholate, but this phenotype is not dependent on the presence of BaeS. (EcoCyc)

BaeSR Two-Component Signal Transduction System References