title: Release of 7-methylguanine residues from alkylated DNA by extracts of Micrococcus luteus and Escherichia coli.
abstract: 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.
mesh_terms: D000818:Animals; D002417:Cattle; D004247:DNA; D004926:Escherichia coli / Q000378:metabolism*; D006147:Guanine / Q000031:analogs & derivatives* / Q000032:analysis; D007700:Kinetics; D008745:Methylation; D008837:Micrococcus / Q000378:metabolism*; D013950:Thymus Gland
chemical_list: D006147:Guanine; C008450:7-methylguanine; D004247:DNA