Présentation
In Salmonella enterica serovar Typhimurium and many other Gram negative bacteria, SigmaS (RpoS) activates global gene expression and controls adaptive functions including stress resistance, biofilm formation and virulence. SigmaS also downregulates housekeeping metabolic and membrane functions. Downregulation by SigmaS might target genes that are deleterious for persistence of nongrowing cells when they are fully expressed. Understanding the mechanisms by which full expression of these genes results in a fitness cost might provide novel insights into the survival mechanisms and evolution of non-actively growing bacterial populations, with important implications for antibacterial strategies.
