title: Strand-break formation in DNA modified by benzo[alpha]pyrene diolepoxide. Quantitative cleavage by Escherichia coli uvrABC endonuclease.
abstract: Covalently closed circular plasmid DNA was modified by benzo[alpha]pyrene diolepoxide and incubated with partially purified fractions of the Escherichia coli uvr+ gene products. Strand breaks were introduced into the modified DNA by the uvrABC endonuclease; on average, one break was formed for each bound benzo[alpha]pyrene residue in the DNA. These results are direct evidence that benzo[alpha]pyrene adducts in DNA are acted upon by the same repair enzyme as those that handle UV-induced lesions in DNA.
mesh_terms: D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D001580:Benzopyrenes / Q000494:pharmacology*; D004260:DNA Repair / Q000187:drug effects*; D004262:DNA Restriction Enzymes / Q000502:physiology*; D004269:DNA, Bacterial / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology; D010957:Plasmids / Q000187:drug effects
chemical_list: D001580:Benzopyrenes; D004269:DNA, Bacterial; D015123:7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide; D004262:DNA Restriction Enzymes