DNA-damaging agents stimulate gene expression at specific loci in Escherichia coli.
Operon fusions in Escherichia coli were obtained that showed increased beta-galactosidase expression in response to treatment with the DNA-damaging agent mitomycin C. These fusions were generated by using the Mud(ApR, lac) vector [Casadaban, M.J. & Cohen, S.N. (1979) Proc. Natl. Acad. Sci. USA 76, 4530-4533] to insert the lactose structural genes randomly into the bacterial chromosome. Induction of beta-galactosidase in these strains, which carried fusions of lac to these din (damage-inducible) loci, was (i) triggered by UV light as well as by mitomycin C and (ii) abolished by either a recA- or a lexA- mutation. Similar characteristics of induction were observed when the lactose genes were fused to a prophage lambda promoter by using Mud(ApR, lac). These results indicate that E. coli contains a set of genes that, like prophage lambda genes, are expressed in response to DNA-damaging agents and regulated by the recA and lexA gene products. These din genes map at five bacterial loci. One din::Mud(ApR, lac) insertion results in a UV-sensitive phenotype and may be within the uvrA transcriptional unit.
D004260:DNA Repair; D004269:DNA, Bacterial / Q000235:genetics*; D004790:Enzyme Induction / Q000187:drug effects / Q000528:radiation effects; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D007763:Lac Operon; D008937:Mitomycins / Q000494:pharmacology*; D011995:Recombination, Genetic; D014466:Ultraviolet Rays; D001616:beta-Galactosidase / Q000235:genetics
D004269:DNA, Bacterial; D008937:Mitomycins; D001616:beta-Galactosidase