Effect of an umuC mutation on phage lambda induction.
A possible role of the umuC gene product in the induction of the SOS responses was examined. We compared the expression of a genetic fusion, in which gene lacZ, encoding beta-galactosidase in Escherichia coli is under the direct control of the cI repressor from prophage lambda, in a umuC+ strain and in an otherwise isogenic umuC- mutant. We found that two times higher UV doses were required to obtain a similar induction in the umuC+ strain as in the umuC mutant. In addition we showed that, at the same UV dose after a lag period, the specific activity of beta-galactosidase increased more rapidly in the umuC mutant. We suggest that the wild-type umuC gene product participates in the processing of the SOS inducing structures caused by UV irradiation or prevents formation of some of them. This is compatible with a role of the UmuC protein in DNA synthesis past a replication block.
D010582:Bacteriophage lambda / Q000235:genetics* / Q000528:radiation effects; D004260:DNA Repair; D004926:Escherichia coli / Q000235:genetics*; D005796:Genes / Q000528:radiation effects; D005814:Genes, Viral / Q000528:radiation effects; D005838:Genotype; D009154:Mutation; D014466:Ultraviolet Rays; D014764:Viral Proteins / Q000235:genetics*
D014764:Viral Proteins