title: [Possible origin and evolution of enzymatic methylation of eukaryotic DNA. Methylation of cytosine residues in 3 palindromic families: RYRY, YYRR, and YYRYRR].
abstract: Data on nearest neighbors of 5-methylcytosine residues in eukaryotic DNA were analyzed. It was found that the methylation sites C*G and C*NG may be located in three palindromic families: RYRY, YYRR and YYRYRR. It was shown that all the methylated sequences in these DNAs can appear as a result of 5-MeC----T substitutions, proceeding by deamination of 5-MeC residues in the "prototype" sites of each of these families: G*CGC*, C*C*GG and C*C*GCGG. The multiplicity of DNA-methyltransferases in eukaryotic cells and their evolutionary origin from prokaryotic type II methylases, recognizing analogous sequences in DNA, are discussed.
authors.forename: A L
authors.initials: AL
authors.lastname: Mazin
authors.forename: B F
authors.initials: BF
authors.lastname: Vaniushin
mesh_terms: D044503:5-Methylcytosine; D000818:Animals; D005075:Biological Evolution; D003596:Cytosine / Q000031:analogs & derivatives* / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D015254:DNA Modification Methylases; D015252:Deoxyribonucleases, Type II Site-Specific; D005057:Eukaryotic Cells; D006801:Humans; D008745:Methylation; D008969:Molecular Sequence Data; D009154:Mutation; D012091:Repetitive Sequences, Nucleic Acid; D013045:Species Specificity
chemical_list: D044503:5-Methylcytosine; D003596:Cytosine; D004247:DNA; D015254:DNA Modification Methylases; D015252:Deoxyribonucleases, Type II Site-Specific
vernacular_title: O vozmozhnom proiskhozhdenii i évoliutsii énzimaticheskogo metilirovaniia DNK éukariot. Metilirovanie tsitozinovykh ostatkov v trekh semeĭstvakh palindromov: RYRY, YYRR i YYRYRR.