Proteolysis of σS (RpoS) and the general stress response in Escherichia coli

The σS (RpoS) subunit of RNA polymerase is the master regulator of the general stress response in Escherichia coli. Regulation of σS occurs at the levels of transcription, translation, proteolysis and protein activity. As σS has become a paradigm for regulated proteolysis in bacteria, this review summarizes our current knowledge about the molecular mechanisms and multiple signal integration in σS degradation.