novel allele of RAD52 that causes severe DNA repair and recombination deficiencies only in the absence of RAD51 or RAD59

• Published in: Genetics (Austin) 1999-11, Vol.153 (3), p.1117-1130
• Main Authors: Bai, Y, Davis, A.P, Symington, L.S
• Format: Article
• Language: English
• Subjects: Alleles; allelic recombination; Amino Acid Substitution; binding proteins; dna modification; DNA repair; DNA Repair - genetics; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; double strand breaks; Fungal Proteins - genetics; gamma radiation; Gamma Rays; genes; Genotype; heteroallelic recombination; homologous recombination; inverted repeat recombination; mating type switching; meiosis; mitotic recombination; Mutagenesis, Site-Directed; mutants; mutation; phenotype; Point Mutation; Polymerase Chain Reaction; Rad51 Recombinase; Rad52 DNA Repair and Recombination Protein; Recombination, Genetic; resistance; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - radiation effects; Saccharomyces cerevisiae Proteins; sporulation; Suppression, Genetic
• ISSN: 0016-6731; 1943-2631; 1943-2631
• DOI: 10.1093/genetics/153.3.1117

With the use of an intrachromosomal inverted repeat as a recombination reporter, we have shown that mitotic recombination is dependent on the RAD52 gene, but reduced only fivefold by mutation of RAD51. RAD59, a component of the RAD51-independent pathway, was identified previously by screening for mutations that reduced inverted-repeat recombination in a rad51 strain. Here we describe a rad52 mutation, rad52R70K, that also reduced recombination synergistically in a rad51 background. The phenotype of the rad52R70K strain, which includes weak gamma-ray sensitivity, a fourfold reduction in the rate of inverted-repeat recombination, elevated allelic recombination, sporulation proficiency, and a reduction in the efficiency of mating-type switching and single-strand annealing, was similar to that observed for deletion of the RAD59 gene. However, rad52R70K rad59 double mutants showed synergistic defects in ionizing radiation resistance, sporulation, and mating-type switching. These results suggest that Rad52 and Rad59 have partially overlapping functions and that Rad59 can substitute for this function of Rad52 in a RAD51 rad52R70K strain.