Activity of nucleotide excision repair enzymes for oxanine cross-link lesions.
Nitric oxide and nitrous acid induce deamination of DNA bases, resulting in uracil, hypoxanthine, xanthine, and oxanine (Oxa) as major damage. Oxa reacts further with polyamines and DNA binding proteins, generating bulky cross-link adducts. Recently we have shown Oxa and cross-link adducts are potentially genotoxic lesions. In the present study, we have assessed the role of base excision repair (BER) and nucleotide excision repair (NER) systems in the repair of Oxa and Oxa-spermine (Oxa-Sp) cross-link adducts. Oxa was very poorly removed from DNA by both BER glycosylases and NER enzymes, whereas Oxa-Sp was efficiently excised by E. coli and human NER enzymes.
Nakano
Toshiaki
T
Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan.
Katafuchi
Atsushi
A
Terato
Hiroaki
H
Suzuki
Toshinori
T
Van Houten
Bennett
B
Ide
Hiroshi
H
D018736:DNA Adducts / Q000737:chemistry / Q000378:metabolism*; D045647:DNA Glycosylases / Q000378:metabolism; D004260:DNA Repair; D045643:DNA Repair Enzymes / Q000378:metabolism*; D006801:Humans; D011684:Purine Nucleosides / Q000737:chemistry / Q000378:metabolism*; D013096:Spermine / Q000031:analogs & derivatives / Q000378:metabolism
D018736:DNA Adducts; D011684:Purine Nucleosides; C468766:oxanine; D013096:Spermine; D045647:DNA Glycosylases; D045643:DNA Repair Enzymes