Strain-Specific Gifsy-1 Prophage Genes Are Determinants for Expression of the RNA Repair Operon during the SOS Response in Salmonella enterica Serovar Typhimurium.

The adaptation of Salmonella enterica serovar Typhimurium to stress conditions involves expression of genes within the regulon of the alternative sigma factor RpoN (σ). RpoN-dependent transcription requires an activated bacterial enhancer binding protein (bEBP) that hydrolyzes ATP to remodel the RpoN-holoenzyme-promoter complex for transcription initiation. The bEBP RtcR in Typhimurium strain 14028s is activated by genotoxic stress to direct RpoN-dependent expression of the RNA repair operon The molecular signal for RtcR activation is an oligoribonucleotide with a 3'-terminal 2',3'-cyclic phosphate.