title: Auto-methylation of the mouse DNA-(cytosine C5)-methyltransferase Dnmt3a at its active site cysteine residue.
abstract: The Dnmt3a DNA methyltransferase is responsible for establishing DNA methylation patterns during mammalian development. We show here that the mouse Dnmt3a DNA methyltransferase is able to transfer the methyl group from S-adenosyl-l-methionine (AdoMet) to a cysteine residue in its catalytic center. This reaction is irreversible and relatively slow. The yield of auto-methylation is increased by addition of Dnmt3L, which functions as a stimulator of Dnmt3a and enhances its AdoMet binding. Auto-methylation was observed in binary Dnmt3a AdoMet complexes. In the presence of CpG containing dsDNA, which is the natural substrate for Dnmt3a, the transfer of the methyl group from AdoMet to the flipped target base was preferred and auto-methylation was not detected. Therefore, this reaction might constitute a regulatory mechanism which could inactivate unused DNA methyltransferases in the cell, or it could simply be an aberrant side reaction caused by the high methyl group transfer potential of AdoMet.
  Dnmt3a is a DNA-(cytosine C5)-methyltransferase, EC 2.1.1.37.
  • Dnmt3a methylates Dnmt3a by methyltransferase assay (View interaction) • Dnmt3a and DNMT3L methylate Dnmt3a by methyltransferase assay (View interaction).
authors.affiliation: Biochemistry Laboratory, School of Engineering and Science, Jacobs University Bremen, Germany.
authors.forename: Abu Nasar
authors.initials: AN
authors.lastname: Siddique
authors.forename: Renata Z
authors.initials: RZ
authors.lastname: Jurkowska
authors.forename: Tomasz P
authors.initials: TP
authors.lastname: Jurkowski
authors.forename: Albert
authors.initials: A
authors.lastname: Jeltsch
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D001483:Base Sequence; D020134:Catalytic Domain; D003545:Cysteine / Q000737:chemistry; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000090205:DNA Methyltransferase 3A; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008745:Methylation; D051379:Mice; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012435:S-Adenosylhomocysteine / Q000378:metabolism; D012436:S-Adenosylmethionine / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: C408982:CPG-oligonucleotide; C000717967:DNMT3A protein, human; C000715535:Dnmt3a protein, mouse; D009838:Oligodeoxyribonucleotides; D011994:Recombinant Proteins; D012436:S-Adenosylmethionine; D012435:S-Adenosylhomocysteine; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A; D003545:Cysteine