The yeast recombinational repair protein Rad59 interacts with Rad52 and stimulates single-strand annealing.
The yeast RAD52 gene is essential for homology-dependent repair of DNA double-strand breaks. In vitro, Rad52 binds to single- and double-stranded DNA and promotes annealing of complementary single-stranded DNA. Genetic studies indicate that the Rad52 and Rad59 proteins act in the same recombination pathway either as a complex or through overlapping functions. Here we demonstrate physical interaction between Rad52 and Rad59 using the yeast two-hybrid system and co-immunoprecipitation from yeast extracts. Purified Rad59 efficiently anneals complementary oligonucleotides and is able to overcome the inhibition to annealing imposed by replication protein A (RPA). Although Rad59 has strand-annealing activity by itself in vitro, this activity is insufficient to promote strand annealing in vivo in the absence of Rad52. The rfa1-D288Y allele partially suppresses the in vivo strand-annealing defect of rad52 mutants, but this is independent of RAD59. These results suggest that in vivo Rad59 is unable to compete with RPA for single-stranded DNA and therefore is unable to promote single-strand annealing. Instead, Rad59 appears to augment the activity of Rad52 in strand annealing.
Davis
A P
AP
Department of Microbiology and Institute of Cancer Research, Columbia University College of Physicians and Surgeons, New York, New York 10032, USA.
Symington
L S
LS
D001483:Base Sequence; D017931:DNA Primers; D004260:DNA Repair / Q000235:genetics*; D004271:DNA, Fungal / Q000235:genetics*; D004277:DNA, Single-Stranded / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005656:Fungal Proteins / Q000378:metabolism*; D009154:Mutation; D011233:Precipitin Tests; D011485:Protein Binding; D051721:Rad52 DNA Repair and Recombination Protein; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D017384:Sequence Deletion
D017931:DNA Primers; D004271:DNA, Fungal; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C497197:RAD52 protein, S cerevisiae; C400213:RAD59 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins