The dps promoter is activated by OxyR during growth and by IHF and sigma S in stationary phase.
Dps is a non-specific DNA-binding protein abundant in starved Escherichia coli cells and is important for the defence against hydrogen peroxide. We found that dps mRNA levels are controlled by rpoS-encoded sigma S, the transcriptional activator OxyR and the histone-like IHF protein. In exponentially growing cells, dps is induced by treatment with hydrogen peroxide in an OxyR-dependent manner. This OxyR-dependent induction occurs only during log phase, although the OxyR protein is present in stationary phase. In the stationary phase cells, dps is expressed in a sigma S- and IHF-dependent manner. The purified OxyR and IHF proteins are also shown to bind upstream of the dps promoter. Our results suggest that the dps promoter is recognized by both sigma 70-holoenzyme and sigma S-holoenzyme, since OxyR acts through sigma 70 and the starts of the OxyR- and sigma S-dependent transcripts are identical.
Altuvia
S
S
Cell Biology and Metabolism Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892.
Almirón
M
M
Huisman
G
G
Kolter
R
R
Storz
G
G
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D006861:Hydrogen Peroxide / Q000494:pharmacology; D034982:Integration Host Factors; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins; D012808:Sigma Factor / Q000378:metabolism*; D014157:Transcription Factors
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C083911:DPS protein, Bacteria; D029968:Escherichia coli Proteins; D034982:Integration Host Factors; D012097:Repressor Proteins; D012808:Sigma Factor; D014157:Transcription Factors; C499299:oxyR protein, E coli; C069567:sigma factor KatF protein, Bacteria; D006861:Hydrogen Peroxide; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases