Effect of DNA topology on plasmid DNA repair in vivo.
Escherichia coli nucleotide excision repair (NER) is responsible for removing bulky DNA adducts by dual incisions of the UvrABC endonuclease. Although the activity of the UvrAB complex which can induce DNA conformational change is employed in NER, the involvement of DNA topology and DNA topoisomerases remains unclear. We examined the effect of topoisomerase inhibitions on a NER in vivo system. The repair analysis of intracellular plasmid revealed that the DNA damage on positive supercoils generated by gyrase inhibition remained unrepaired, whereas the DNA damage was repaired in topoisomerase I mutants. These results suggest that DNA topology affects the NER process and the removal of positive supercoils by gyrase is vital for the efficiency of the E. coli NER system.
Department of Molecular Microbiology, University of Ulsan, Nam-Ku MooGeo-Dong, 680-749, Ulsan, South Korea.
J Y
JY
Park
B
B
Ahn
D004256:DNA Polymerase I / Q000378:metabolism; D004260:DNA Repair / Q000187:drug effects; D004264:DNA Topoisomerases, Type I / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry* / Q000378:metabolism* / Q000528:radiation effects; D004278:DNA, Superhelical / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects; D009154:Mutation; D009675:Novobiocin / Q000494:pharmacology; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000737:chemistry* / Q000378:metabolism* / Q000528:radiation effects; D059005:Topoisomerase II Inhibitors; D014466:Ultraviolet Rays
D004269:DNA, Bacterial; D004278:DNA, Superhelical; D059005:Topoisomerase II Inhibitors; D009675:Novobiocin; D004256:DNA Polymerase I; D004264:DNA Topoisomerases, Type I