DNA repair synthesis in toluenized Escherichia coli treated with 8-methoxypsoralen and 365-nm light.
Irradiation of permeable Escherichia coli in the presence of 8-methoxypsoralen was found to elicit DNA-repair synthesis. The incorporation depended on the uvrA+ and polA+ genes, but was unaffected by mutations at recA, B or C. Double-irradiation experiments, in which the relative influence of monoadducts and crosslinks could be measured, revealed that the repair synthesis initiated at monoadducts in the DNA. Thus these lesions appear to be subject to conventional excision repair. Crosslinks, however, blocked extensive synthesis. The significance of these results is considered in the light of recent results in vivo.
D004260:DNA Repair; D004261:DNA Replication; D004269:DNA, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000528:radiation effects; D011701:PUVA Therapy; D010778:Photochemotherapy; D011740:Pyrimidine Dimers / Q000235:genetics; D013997:Time Factors; D014466:Ultraviolet Rays
D004269:DNA, Bacterial; D011740:Pyrimidine Dimers