groE genes affect SOS repair in Escherichia coli.
Repair of UV-irradiated bacteriophage in Escherichia coli by Weigle reactivation requires functional recA+ and umuD+C+ genes. When the cells were UV irradiated, the groE heat shock gene products, GroES and GroEL, were needed for at least 50% of the Weigle reactivation of the single-stranded DNA phage S13. Because of repression of the umuDC and recA genes, Weigle reactivation is normally blocked by the lexA3(Ind-) mutation (which creates a noncleavable LexA protein), but it was restored by a combination of a high-copy-number umuD+C+ plasmid and a UV dose that increases groE expression. Maximal reactivation was achieved by elevated amounts of the Umu proteins, which was accomplished in part by UV-induced expression of the groE genes. By increasing the number of copies of the umuD+C+ genes, up to 50% of the normal amount of reactivation of S13 was achieved in an unirradiated recA+ host.
Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907.
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D003090:Coliphages / Q000235:genetics* / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000235:genetics* / Q000528:radiation effects; D005798:Genes, Bacterial; D005838:Genotype; D006360:Heat-Shock Proteins / Q000235:genetics*; D009154:Mutation; D011938:Rec A Recombinases / Q000235:genetics; D013014:SOS Response, Genetics; D014466:Ultraviolet Rays
D006360:Heat-Shock Proteins; D011938:Rec A Recombinases