title: A candidate mammalian DNA methyltransferase related to pmt1p of fission yeast.
abstract: Trace levels of 5-methylcytosine persist in the DNA of mouse embryonic stem cells that are homozygous for null mutations in Dnmt1 , the gene for the one previously recognized metazoan DNA methyltransferase. This residual 5-methylcytosine may be the product of a candidate second DNA methyltransferase, Dnmt2, that has now been identified in human and mouse. Dnmt2 contains all the sequence motifs diagnostic of DNA (cytosine-5)-methyltransferases but appears to lack the large N-terminal regulatory domain common to other eukaryotic methyltransferases. Dnmt2 is more similar to a putative DNA methyltransferase of the fission yeast Schizosaccharomyces pombe than to Dnmt1. Dnmt2 produces multiple mRNA species that are present at low levels in all tissues of human and mouse and is not restricted to those cell types known to be active in de novo methylation. The human DNMT2 gene was mapped to chromosome 10p12-10p14 in a panel of radiation hybrids. Dnmt2 is a candidate for the activity that methylates newly integrated retroviral DNA and maintains trace levels of 5-methylcytosine in the DNA of embryonic stem cells homozygous for null mutations in Dnmt1.
authors.affiliation: Department of Genetics and Development, College of Physicians and Surgeons of Columbia University, 701 West 168 Street, New York, NY 10032, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Yoder
authors.forename: T H
authors.initials: TH
authors.lastname: Bestor
mesh_terms: D044503:5-Methylcytosine; D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry; D002874:Chromosome Mapping; D002879:Chromosomes, Human, Pair 10 / Q000235:genetics; D003596:Cytosine / Q000031:analogs & derivatives / Q000032:analysis; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D019175:DNA Methylation; D018076:DNA, Complementary / Q000235:genetics; D019143:Evolution, Molecular; D005326:Fetal Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics*; D015870:Gene Expression; D018390:Gene Targeting; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D051379:Mice / Q000196:embryology / Q000235:genetics*; D008969:Molecular Sequence Data; D012568:Schizosaccharomyces / Q000201:enzymology* / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity; D013234:Stem Cells / Q000201:enzymology
chemical_list: D001426:Bacterial Proteins; D018076:DNA, Complementary; D005326:Fetal Proteins; D005656:Fungal Proteins; D007527:Isoenzymes; D044503:5-Methylcytosine; D003596:Cytosine; D004248:DNA (Cytosine-5-)-Methyltransferases