A Disulfide Bond in the Membrane Protein IgaA Is Essential for Repression of the RcsCDB System.

摘要: IgaA is an integral inner membrane protein that was discovered as repressor of the RcsCDB phosphorelay system in intracellular pathogen Salmonella enterica serovar Typhimurium. The system, conserved many members family Enterobacteriaceae, regulates expression varied processes including motility, biofilm formation, virulence and response to envelope stress. essential which, perturbation, outer lipoprotein RcsF has been proposed bind order activate phosphorelay. Envelope stress also reported be sensed by a surface exposed domain RcsF. These observations support tight control via mechanisms that, however, remain unknown. Interestingly, have four cysteine residues loops periplasmic space. Two non-consecutive disulfide bonds were shown required for function. Here, we report mutagenesis studies supporting presence one bond (C404 C425) major loop repression Our data therefore suggest redox state periplasm may critical its two upstream regulators, IgaA.