title: Elimination of lethal and pre-mutational DNA lesions during the photoreactivation of UV-irradiated Escherichia coli.
abstract: The comparison of the frequency of trp+ revertants of Escherichia coli B/r Hcr+ thy trp after UV-irradiation on the one hand and after UV-irradiation plus photoreactivation on the other showed that both photoreversible pyrimidine dimers of the cyclobutane type and the non-photoreversible DNA lesions cause, at equal lethal effects, also trp+ reversions with the same efficiency. If lethal, the pyrimidine dimers may thus be conceived as primary pre-mutational lesions.
mesh_terms: D003503:Cyclobutanes / Q000378:metabolism; D004260:DNA Repair; D004269:DNA, Bacterial / Q000096:biosynthesis* / Q000528:radiation effects; D004926:Escherichia coli / Q000378:metabolism* / Q000528:radiation effects; D008027:Light; D009154:Mutation; D011743:Pyrimidines / Q000378:metabolism; D011830:Radiation Effects; D014364:Tryptophan / Q000096:biosynthesis; D014466:Ultraviolet Rays
chemical_list: D003503:Cyclobutanes; D004269:DNA, Bacterial; D011743:Pyrimidines; D014364:Tryptophan