title: Postreplicational formation and repair of DNA double-strand breaks in UV-irradiated Escherichia coli uvrB cells.
abstract: The number of DNA double-strand breaks formed in UV-irradiated uvrB recF recB cells correlates with the number of unrepaired DNA daughter-strand gaps, and is dependent on DNA synthesis after UV-irradiation. These results are consistent with the model that the DNA double-strand breaks that are produced in UV-irradiated excision-deficient cells occur as the result of breaks in the parental DNA opposite unrepaired DNA daughter-strand gaps. By employing a temperature-sensitive recA200 mutation, we have devised an improved assay for studying the formation and repair of these DNA double-strand breaks. Possible mechanisms for the postreplication repair of DNA double-strand breaks are discussed.
mesh_terms: D002499:Centrifugation, Density Gradient; D004260:DNA Repair; D004261:DNA Replication; D004269:DNA, Bacterial / Q000378:metabolism / Q000528:radiation effects*; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D008970:Molecular Weight; D009154:Mutation; D011995:Recombination, Genetic; D013696:Temperature; D014466:Ultraviolet Rays
chemical_list: D004269:DNA, Bacterial