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).
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Alcohol Oxidoreductases
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Aminohydrolases
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DNA Repair / physiology*
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DNA Repair Enzymes
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DNA, Fungal / physiology*
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DNA-Binding Proteins / genetics
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DNA-Binding Proteins / physiology*
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Endonucleases / genetics
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Endonucleases / physiology*
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Fungal Proteins / genetics
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Fungal Proteins / physiology*
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Meiosis
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MutS Homolog 2 Protein
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Mutation
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Nucleic Acid Conformation
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Nucleic Acid Heteroduplexes*
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Pyrophosphatases
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Recombination, Genetic
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Saccharomyces cerevisiae / genetics*
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Saccharomyces cerevisiae Proteins*
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Transcription Factors / genetics
Substances
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DNA, Fungal
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DNA-Binding Proteins
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Fungal Proteins
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Nucleic Acid Heteroduplexes
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Saccharomyces cerevisiae Proteins
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Transcription Factors
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Alcohol Oxidoreductases
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HIS4 protein, S cerevisiae
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Endonucleases
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RAD1 protein, S cerevisiae
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Aminohydrolases
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Pyrophosphatases
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MSH2 protein, S cerevisiae
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MutS Homolog 2 Protein
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DNA Repair Enzymes