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Impaired incision of ultraviolet-irradiated deoxyribonucleic acid in uvrC mutants of Escherichia coli

Journal Article · · J. Bacteriol.; (United States)
OSTI ID:6741313
 [1]; ;
  1. Norwegian Defence Research Establishment, Kjeller, Norway

The production of single-strand breaks in the deoxyribonucleic acid of irradiated uvrC mutants of Escherichia coli K-12 was studied both in vivo and in vitro. In vivo, uvrC mutants displayed a slow accumulation of breaks after irradiation, and in this respect appeared different from uvrA mutants, in which very few breaks could be detected. The breakage observed in uvrC mutants differed from that observed in wild-type strains in both the slow rate of break accumulation and the very limited dose response. In toluene-treated cells, we studied the effect of the ligase inhibitor nicotinomide mononucleotide on strand incision. Whereas uvrC mutants displayed more strand breakage in the presence of this inhibitor, the same amount of breakage was seen in uvrA mutants. Experiments using a cell-free system comprising the partially purified uvr/sup +/ gene products demonstrated clearly that there is a requirement for the uvrC/sup +/ gene product for strand incision. We suggest that in vivo in the absence of the uvrC/sup +/ gene product, a partial analog of this protein may allow some abnormal incision.

OSTI ID:
6741313
Journal Information:
J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 144:1; ISSN JOBAA
Country of Publication:
United States
Language:
English