title: Excision in vitro of the DNA bound carcinogen, 4-nitroquinoline 1-oxide.
abstract: It has been shown that 4-hydroxyaminoquinoline 1-oxide, the proximate form of the carcinogen 4-nitroquinoline 1-oxide, binds covalently to the purine bases of DNA. Here we report that carcinogen-bound nucleotides can be excised from DNA by a 5' leads to 3' exonuclease associated with DNA polymerase I of E. coli in the forms of either mononucleotides or oligonucleotides. Beef spleen phosphodiesterase II (5' leads to 3') also split carcinogen-bound nucleotides, while a 3' leads to 5' exonuclease of DNA polymerase I and E. coli exonuclease III (3' leads to 5') could not excise the modified nucleotide.
mesh_terms: D015112:4-Nitroquinoline-1-oxide / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D004247:DNA / Q000378:metabolism; D004256:DNA Polymerase I; D004926:Escherichia coli / Q000201:enzymology; D007700:Kinetics; D009600:Nitroquinolines / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases; D013154:Spleen / Q000201:enzymology
chemical_list: D009600:Nitroquinolines; D015112:4-Nitroquinoline-1-oxide; D004247:DNA; D004256:DNA Polymerase I; D010727:Phosphoric Diester Hydrolases