Protective action of colicinogenic factor Ib-P9 on Escherichia coli cells defective in known repair functions after ultraviolet irradiation
Khmel', I.A.; Kopylov, V.M.; Vorob'eva, I.P.
Genetika 15(9): 1578-1587
1979
ISSN/ISBN: 0016-6758 PMID: 385450 Document Number: 143462
The presence of the plasmid colicinogenic factor Ib-P9 in Escherichia coli wild type cells is shown to increase bacterial survival after UV irradiation and the action of N-methyl-N'-nitro-N-nitrosoguanidine. The ability of the plasmid to cause the UV protection is observed in uvrA, uvrB, uvrC, polA, recB, recF E. coli strains, but the plasmid does not restore the UV resistance of the mutant cells to the wild type level. The protective effect of the plasmid CoI Ib-P9 depends on the recA+lexA+ genotype of the cells. The inhibition of protein synthesis (amino acid starvation) before and after UV irradiation does not prevent the UV protection by ColIb-P9. The nature of the plasmid-associated repair functions is discussed.