A DNA damage response in Escherichia coli involving the alternative sigma factor, RpoS.
We isolated an Escherichia coli mutant in the iraD gene, sensitive to various forms of DNA damage. Our data are consistent with the function of IraD to promote accumulation of the alternative transcription sigma factor, RpoS, by binding to the adaptor RssB protein that targets RpoS for degradation. Our results demonstrate the physiological importance of this mode of regulation for DNA damage tolerance. Although RpoS is best known for its regulation of genes induced in stationary phase, our work underscores the importance of the RpoS regulon in a DNA damage response in actively growing cells. We show that iraD transcription is induced by DNA damage by a mechanism independent of the SOS response. The IraD and SOS regulatory pathways appear to act synergistically to ensure survival of cells faced with oxidative or DNA damaging stress during cellular growth.
Merrikh
Houra
H
Department of Biology and Rosenstiel Basic Medical Sciences Center, Brandeis University, Waltham, MA 02254-9110, USA.
Ferrazzoli
Alexander E
AE
Bougdour
Alexandre
A
Olivier-Mason
Anique
A
Lovett
Susan T
ST
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004249:DNA Damage; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D018085:Regulon; D013014:SOS Response, Genetics; D012808:Sigma Factor / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C535006:IraD protein, E coli; D012808:Sigma Factor; D014157:Transcription Factors; C098923:rssB protein, E coli; C069567:sigma factor KatF protein, Bacteria