Using UvrABC nuclease to detect 7,12-dimethylbenz[a]anthracene anti-diol epoxide-DNA binding specificity in the mouse H-ras gene.
DNA fragments modified with chemically synthesized 7,12-dimethylbenz[a]anthracene anti-diol epoxide (anti-DMBADE) are sensitive to UvrABC nuclease incision. The incisions occur mainly 7 bases 5' and 4 bases 3' of an anti-DMBADE-modified adenine or guanine residue, and the kinetics of incision at different sequences in a DNA fragment are the same. These results indicate that UvrABC incision on anti-DMBADE-DNA adducts is independent of DNA sequences and is quantitative, the same as on syn-DMBADE-DNA adducts. This method was used to analyze the anti-DMBADE-DNA binding spectrum in the exon 2 region of the mouse H-ras gene, and it was found that anti-DMBADE binds to the two adenine residues at codon 61 of the H-ras gene with an average affinity. Previously, we have demonstrated that syn-DMBADE binds strongly to the adenines at codon 61 of H-ras; these results together suggest that the oncogenic mutation in H-ras may be induced by anti- and syn-DMBADE-DNA adducts.
Chen
J X
JX
Department of Carcinogenesis, University of Texas M.D. Anderson Cancer Center, Smithville 78957, USA.
Kisleyou
A S
AS
Harvey
R G
RG
Slaga
T J
TJ
Morris
R J
RJ
Tang
M
M
D015127:9,10-Dimethyl-1,2-benzanthracene / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004706:Endodeoxyribonucleases; D029968:Escherichia coli Proteins; D011905:Genes, ras; D051379:Mice; D008969:Molecular Sequence Data
D029968:Escherichia coli Proteins; D015127:9,10-Dimethyl-1,2-benzanthracene; D004247:DNA; D004706:Endodeoxyribonucleases; C036385:endodeoxyribonuclease uvrABC