Extended model of the SigH regulatory network in C. glutamicum. Conditions that deplete thiols by oxidation or alkylation cause the oxidation of cysteine residues inside RsrA. RsrAox is released from SigH, which then binds to the RNA polymerase (RNAP) and initiates the transcription of its regulon. Direct induction of trxBC/B1, mca, mshC and mtr genes that are involved in the disulphide response generate and recycle/reduce the thiols thioredoxin (Trx) and Mycothiol (MSH) to reverse the oxidation of RsrA, restore thiol redox balance and re-establish the binding of RshA to SigH. The direct induction of rshA as a single transcript amplifies the shutdown of the SigH-dependent response after the cells have coped with the stress. The SigH regulon includes part of the SOS response and the heat-shock regulon, including the HspR and ClgR regulatory networks, which are responsible for protein quality control.
Busche et al. BMC Genomics 2012 13:445 doi:10.1186/1471-2164-13-445