Repair of synthetic oligonucleotides containing O6-methylguanine, O6-ethylguanine and O4-methylthymine, by O6-alkylguanine-DNA alkyltransferase.
32P-Labelled self-complementary oligonucleotides containing O6-methylguanine, O6-ethylguanine, and O4-methylthymine have been synthesized and used as substrates for the DNA repair protein O6-alkylguanine-DNA alkyltransferase (AAT). The reaction was second-order with rate constants of 2.6 X 10(7) M-1 sec-1 for O6-methylguanine, 2.6 X 10(4) M-1 sec-1 for O6-ethylguanine and 2.5 X 10(3) M-1 sec-1 for O4-methylthymine. These oligomers should allow sensitive and specific assay of the mammalian enzyme.
Graves
R J
RJ
Courtauld Institute of Biochemistry, Middlesex Hospital Medical School, London, UK.
Li
B F
BF
Swann
P F
PF
D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004260:DNA Repair; D004926:Escherichia coli / Q000201:enzymology; D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism; D007700:Kinetics; D008780:Methyltransferases / Q000378:metabolism*; D019853:O(6)-Methylguanine-DNA Methyltransferase; D013941:Thymine / Q000031:analogs & derivatives* / Q000378:metabolism
C021223:O-4-methylthymine; C007673:6-ethylguanine; D006147:Guanine; C008449:O-(6)-methylguanine; D008780:Methyltransferases; D019853:O(6)-Methylguanine-DNA Methyltransferase; D013941:Thymine