Release of 7-methylguanine residues from alkylated DNA by extracts of Micrococcus luteus and Escherichia coli.
نویسندگان
چکیده
Cell extracts from Micrococcus luteus release both free 3-methyladenine and free 7-methylguanine from alkylated DNA. The glycosylase activity responsible for the liberation of 7-methylguanine is not 3-methyladenine-DNA glycosylase, which, when purified, does not liberate it. Furthermore, the heat inactivation rates of the two enzymatic activities are different. The release of 7-methylguanine by chemical depurination of ethanol-soluble oligonucleotides has been ruled out. A similar activity releasing 7-methylguanine is also found in Escherichia coli.
منابع مشابه
The enzymatic release of O6-methylguanine and 3-methyladenine from DNA reacted with the carcinogen N-methyl-N-nitrosourea.
Endonuclease II (deoxyribonucleate oligonucleotidohydrolase, EC 3.1.4.30) of Escherichia coli has been shown to break phosphodiester bonds in alkylated DNA and depurinated DNA. The hypothesis that depurination is a step in the mechanism of the reaction with alkylated DNA is supported by in vitro experiments with DNA reacted with N-methyl-N-nitrosourea. Endonuclease II releases O(6)-methylguanin...
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ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 78 2 شماره
صفحات -
تاریخ انتشار 1981