Post-UV survival of Escherichia coli strains carrying more than one UV-sensitising plasmid.
The post-UV phenotypes conferred by wild-type plasmids R391 and pYD1, which increase UV-induced mutagenesis but sensitise Escherichia coli AB1157 umuC+ uvrB+ to UV, were compared, alone and in combination with that of plasmid pGW16, which sensitises AB1157 to low, but protects against high UV doses. All three plasmids increased UV resistance when present in Shigella sonnei. No plasmid significantly affected the UV sensitivity of E. coli TK501 umuC uvrB, in which pKM101, the parent of pGW16 increases UV resistance up to 1000-fold. Both pYD1 and R391 reduced the UV protective effect of pKM101, and increased UV-sensitisation conferred by pGW16. UV-sensitisation conferred by pYD1 and R391 was additive when the plasmids were together in strain AB1157, and both pKM101 and pGW16 reduced this additive sensitisation.
Ambler
J E
JE
Microbiology Section, Department of Pharmaceutics, University of London, UK.
Pinney
R J
RJ
D004260:DNA Repair; D004307:Dose-Response Relationship, Radiation; D004926:Escherichia coli / Q000528:radiation effects*; D010641:Phenotype; D010957:Plasmids; D011836:Radiation Tolerance / Q000235:genetics*; D012764:Shigella sonnei / Q000528:radiation effects; D013045:Species Specificity; D014466:Ultraviolet Rays / Q000009:adverse effects*