title: Chemical adaptation of M. luteus induces repair functions for O-alkylated DNA pyrimidines.
abstract: A partially purified extract prepared from adapted M. luteus cells contains repair functions for oxygen methylated pyrimidine residues present in alkylated DNA. The removal of O2-MeT is mediated by a DNA glycosylase enzyme whereas disappearance of O4-MeT is effected by a methyltransferase in a manner similar to the in situ repair of O6-MeG. O4-MeT methyltransferase enzyme is unusually heat resistant. Synthesis of these repair proteins, which are distinctly different from the previously known inducible 3-MeA DNA glycosylase and O6-MeG methyltransferase activities, forms a part of the adaptive response.
mesh_terms: D045647:DNA Glycosylases; D004260:DNA Repair; D006358:Hot Temperature; D008745:Methylation; D008769:Methylnitronitrosoguanidine / Q000633:toxicity; D008780:Methyltransferases / Q000378:metabolism*; D008837:Micrococcus / Q000235:genetics*; D009699:N-Glycosyl Hydrolases / Q000378:metabolism; D011742:Pyrimidine Nucleotides / Q000378:metabolism*
chemical_list: D011742:Pyrimidine Nucleotides; D008769:Methylnitronitrosoguanidine; D008780:Methyltransferases; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases