Repair of DNA loops involves DNA-mismatch and nucleotide-excision repair proteins

Nature. 1997 Jun 26;387(6636):929-31. doi: 10.1038/43225.


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).

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alcohol Oxidoreductases
  • Aminohydrolases
  • DNA Repair / physiology*
  • DNA Repair Enzymes
  • DNA, Fungal / physiology*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Endonucleases / genetics
  • Endonucleases / physiology*
  • Fungal Proteins / genetics
  • Fungal Proteins / physiology*
  • Meiosis
  • MutS Homolog 2 Protein
  • Mutation
  • Nucleic Acid Conformation
  • Nucleic Acid Heteroduplexes*
  • Pyrophosphatases
  • Recombination, Genetic
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins*
  • Transcription Factors / genetics


  • DNA, Fungal
  • DNA-Binding Proteins
  • Fungal Proteins
  • Nucleic Acid Heteroduplexes
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Alcohol Oxidoreductases
  • HIS4 protein, S cerevisiae
  • Endonucleases
  • RAD1 protein, S cerevisiae
  • Aminohydrolases
  • Pyrophosphatases
  • MSH2 protein, S cerevisiae
  • MutS Homolog 2 Protein
  • DNA Repair Enzymes