A bacterial hemerythrin-like protein MsmHr inhibits the SigF-dependent hydrogen peroxide response in mycobacteria.

摘要: Hydrogen peroxide (H2O2) is one of a variety reactive oxygen species (ROS) produced by aerobic organisms. Host production toxic H2O2 in response to pathogen infection an important classical innate defense mechanism against invading microbes. Understanding the mechanisms which pathogens, oxidative stress, mediate ROS, can reveal anti-microbial targets and shed light on pathogenic mechanisms. In this study, we provide evidence that Mycobacterium smegmatis hemerythrin-like protein MSMEG_2415, designated MsmHr, H2O2-modulated repressor SigF-mediated H2O2. Circular dichroism spectrophotometric analysis MsmHr revealed properties characteristic typical protein. An msmHr knockout strain M. mc2155 (ΔmsmHr) was more resistant than its parental strain, overexpression increased mycobacterial susceptibility Mutagenesis studies hemerythrin domain required for regulation observed study. We show inhibits expression SigF (MSMEG_1804), alternative sigma factor plays role bacterial stress responses, including those elicited H2O2, thus providing mechanistic link between ΔmsmHr enhanced resistance Together, these results strongly suggest involved mycobacteria negatively regulating factor, function not previously described hemerythrins.