title: Repair of DNA loops involves DNA-mismatch and nucleotide-excision repair proteins.
abstract: A number of enzymes recognize and repair DNA lesions. The DNA-mismatch repair system corrects base-base mismatches and small loops, whereas the nucleotide-excision repair system removes pyrimidine dimers and other helix-distorting lesions. DNA molecules with mismatches or loops can arise as a consequence of heteroduplex formation during meiotic recombination. In the yeast Saccharomyces cerevisiae, repair of mismatches results in gene conversion or restoration, and failure to repair the mismatch results in post-meiotic segregation (PMS). The ratio of gene-conversion to PMS events reflects the efficiency of DNA repair. By examining the PMS patterns in yeast strains heterozygous for a mutant allele with a 26-base-pair insertion, we find that the repair of 26-base loops involves Msh2 (a DNA-mismatch repair protein) and Rad1 (a protein required for nucleotide-excision repair).
authors.affiliation: Department of Biology, Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, 27599-3280, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Kirkpatrick
authors.forename: T D
authors.initials: TD
authors.lastname: Petes
mesh_terms: D000429:Alcohol Oxidoreductases; D000619:Aminohydrolases; D004260:DNA Repair / Q000502:physiology*; D045643:DNA Repair Enzymes; D004271:DNA, Fungal / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000502:physiology*; D004720:Endonucleases / Q000235:genetics / Q000502:physiology*; D005656:Fungal Proteins / Q000235:genetics / Q000502:physiology*; D008540:Meiosis; D051718:MutS Homolog 2 Protein; D009154:Mutation; D009690:Nucleic Acid Conformation; D009692:Nucleic Acid Heteroduplexes; D011755:Pyrophosphatases; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics
chemical_list: D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D009692:Nucleic Acid Heteroduplexes; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000429:Alcohol Oxidoreductases; C092116:HIS4 protein, S cerevisiae; D004720:Endonucleases; C069266:RAD1 protein, S cerevisiae; D000619:Aminohydrolases; D011755:Pyrophosphatases; C489751:MSH2 protein, S cerevisiae; D051718:MutS Homolog 2 Protein; D045643:DNA Repair Enzymes