title: [Non-enzymatic DNA methylation by S-adenosylmethionine results in the formation of minor thymine residues and 5-methylcytosine from cytosine].
abstract: It was found that nonenzymatic DNA methylation proceeds in water solution in the presence of S-adenosylmethionine (AdoMet). The main reaction products are thymine and 5-methylcytosine residues. It was shown that labelled thymine residues are formed also upon DNA incubation in the presence of [methyl-14C]methionine as well as [methyl-14C]cobalamine. Only cytosine reacts with AdoMet resulting in thymine production. AdoMet may be a potential mutagen that induces GC----AT transitions during DNA replication in the cell.
mesh_terms: D044503:5-Methylcytosine; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D003596:Cytosine / Q000031:analogs & derivatives* / Q000096:biosynthesis; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D066298:In Vitro Techniques; D008715:Methionine / Q000494:pharmacology; D008745:Methylation; D009154:Mutation; D012436:S-Adenosylmethionine / Q000494:pharmacology*; D013154:Spleen / Q000378:metabolism; D013941:Thymine / Q000096:biosynthesis*
chemical_list: D044503:5-Methylcytosine; D012436:S-Adenosylmethionine; D003596:Cytosine; D004247:DNA; D008715:Methionine; D013941:Thymine
vernacular_title: Neénzimaticheskoe metilirovanie DNK pod deĭstviem S-adenozilmetionina s obrazovaniem iz tsitozina ostatkov minornogo timina i 5-metiltsitozina.