UspB, a member of the sigma-S regulon, facilitates RuvC resolvase function.
A growing body of evidence shows that there is an intimate connection between proteins required for genome stability and stationary phase survival. In this work we show that the integral membrane protein UspB, a member of the RpoS regulon, is required for proper DNA repair as mutants lacking uspB are hypersensitive to several DNA damaging agents including ultraviolet light, mitomycin C, bleomycin and ciprofloxacin. Genetic and physical studies demonstrate that UspB acts in the RuvABC recombination repair pathway and removing uspB creates a phenocopy of the Holliday junction resolvase mutant, ruvC. Further, we show that the uspB mutant phenotype can be suppressed by ectopic overproduction of RuvC and that both ruvC and uspB mutants can be suppressed by inactivating recD. The fact that RuvABC-dependent repair requires UspB for proper activity suggests that the sigma-S regulon works together with DNA repair pathways under stress conditions to defend the cell against genotoxic stress.
Persson
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O
Department of Microbiology, Institute of Cell and Molecular Biology, University of Gothenburg, Göteborg, Sweden.
Nyström
T
T
Farewell
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A
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D004260:DNA Repair / Q000235:genetics / Q000528:radiation effects; D004706:Endodeoxyribonucleases / Q000096:biosynthesis / Q000378:metabolism*; D048168:Escherichia coli K12 / Q000235:genetics* / Q000378:metabolism* / Q000528:radiation effects; D029968:Escherichia coli Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000528:radiation effects; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010641:Phenotype; D011995:Recombination, Genetic; D018085:Regulon; D012808:Sigma Factor / Q000235:genetics* / Q000378:metabolism; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D012808:Sigma Factor; C116144:UspB protein, E coli; C069806:ruvC protein, E coli; C069567:sigma factor KatF protein, Bacteria; D004706:Endodeoxyribonucleases