title: The fission yeast gene pmt1+ encodes a DNA methyltransferase homologue.
abstract: DNA methylation of cytosine residues is a widespread phenomenon and has been implicated in a number of biological processes in both prokaryotes and eukaryotes. This methylation occurs at the 5-position of cytosine and is catalyzed by a distinct family of conserved enzymes, the cytosine-5 methyltransferases (m5C-MTases). We have cloned a fission yeast gene pmt1+ (pombe methyltransferase) which encodes a protein that shares significant homology with both prokaryotic and eukaryotic m5C-MTases. All 10 conserved domains found in these enzymes are present in the pmt1 protein. This is the first m5C-MTase homologue cloned from a fungal species. Its presence is surprising, given the inability to detect DNA methylation in yeasts. Haploid cells lacking the pmt1+ gene are viable, indicating that pmt1+ is not an essential gene. Purified, bacterially produced pmt1 protein does not possess obvious methyltransferase activity in vitro. Thus the biological significance of the m5C-MTase homologue in fission yeast is currently unclear.
authors.affiliation: Institute of Cell and Molecular Biology, University of Edinburgh, UK.
authors.forename: C R
authors.initials: CR
authors.lastname: Wilkinson
authors.forename: R
authors.initials: R
authors.lastname: Bartlett
authors.forename: P
authors.initials: P
authors.lastname: Nurse
authors.forename: A P
authors.initials: AP
authors.lastname: Bird
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017124:Conserved Sequence; D003596:Cytosine / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015257:DNA-Cytosine Methylases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017353:Gene Deletion; D005800:Genes, Fungal; D008745:Methylation; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012436:S-Adenosylmethionine / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017385:Sequence Homology
chemical_list: D029702:Schizosaccharomyces pombe Proteins; D012436:S-Adenosylmethionine; D003596:Cytosine; D004247:DNA; D015257:DNA-Cytosine Methylases; D004248:DNA (Cytosine-5-)-Methyltransferases; C578376:Pmt1 protein, S pombe