title: The UV excision-repair system of Saccharomyces cerevisiae is involved in the removal of methylcytosines formed in vivo by a cloned prokaryotic DNA methyltransferase.
abstract: DNA methyltransferase activity is not normally found in yeast. To investigate the response of Saccharomyces cerevisiae to the presence of methylated bases, we introduced the Bacillus subtilis SPR phage DNA-[cytosine-5] methyltransferase gene on the shuttle vector, YEp51. The methyltransferase gene was functionally expressed in yeast under the control of the inducible yeast GAL 10 promoter. Following induction we observed a time-dependent methylation of yeast DNA in RAD+ and rad2 mutant strains; the rad2 mutant is defective in excision-repair of UV-induced DNA damage. Analysis of restriction endonuclease digestion patterns revealed that the relative amount of methylated DNA was greater in the excision defective rad2 mutant than in the RAD+ strain. These data indicate that the yeast excision-repair system is capable of recognizing and removing m5C residues.
authors.affiliation: Department of Biology, University Medical School, Debrecen, Hungary.
authors.forename: Z
authors.initials: Z
authors.lastname: Fehér
authors.forename: S L
authors.initials: SL
authors.lastname: Schlagman
authors.forename: Z
authors.initials: Z
authors.lastname: Miner
authors.forename: S
authors.initials: S
authors.lastname: Hattman
mesh_terms: D044503:5-Methylcytosine; D003596:Cytosine / Q000031:analogs & derivatives / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism*; D004249:DNA Damage; D004260:DNA Repair; D004271:DNA, Fungal / Q000378:metabolism*; D008745:Methylation; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014170:Transformation, Genetic; D014466:Ultraviolet Rays
chemical_list: D004271:DNA, Fungal; D044503:5-Methylcytosine; D003596:Cytosine; D004248:DNA (Cytosine-5-)-Methyltransferases