[Plasmid pKM101 sensitization of Escherichia coli strains to the action of ionizing radiation: the effect of the plasmid on survivability and induced mutagenesis].

The wild type Escherichia coli K-12 has been shown to be sensitized to inactivation by gamma-irradiation by the plasmid pKM101. The dnaA strains of E. coli are more sensitive to gamma-rays killing effect, as compared with the wild type E. coli, pKM101 plasmid showing only slight sensitizing effect. "Cis" or "trans" position of the plasmid in relation to the chromosome plays no role in sensitization, while the plasmid effect on UV-induced killing and mutability depends on "trans" position of the plasmid before irradiation. gamma-Rays induced mutability to prototrophy is completely dependent on the presence of pKM101 in "trans" in wild type and dnaA strains before irradiation.