The upstream region of theEnterohacter cloacae strain CECT960rpoS gene was sequenced. AnIS10R element was found within thenlpD gene, betweenrpoSp andrpoS. TherpoS promoter, although functional, did not drive transcription of the gene in this strain. However,rpoS transcription depended on this promoter in strains that lacked the insertion sequence innlpD. rpoSp showed growth-phase-dependent, σs-independent regulation. Transcription fromrpoSp was strongly inhibited by glucose even though it was cAMP-receptor-protein (CRP)-independent. Its functionality was also independent of both integration host factor (IHF) and the alarmone ppGpp. RpoS-dependent resistance to some environmental stresses showed a quantitative response to RpoS levels under some conditions (alkaline pH and high osmolarity) but not others (acidic pH, high temperature, and UV irradiation).