DNA annealing mediated by Rad52 and Rad59 proteins.
In the budding yeast Saccharomyces cerevisiae, the RAD52 gene is essential for all homologous recombination events and its homologue, the RAD59 gene, is important for those that occur independently of RAD51. Both Rad52 and Rad59 proteins can anneal complementary single-stranded (ss) DNA. We quantitatively examined the ssDNA annealing activity of Rad52 and Rad59 proteins and found significant differences in their biochemical properties. First, and most importantly, they differ in their ability to anneal ssDNA that is complexed with replication protein A (RPA). Rad52 can anneal an RPA-ssDNA complex, but Rad59 cannot. Second, Rad59-promoted DNA annealing follows first-order reaction kinetics, whereas Rad52-promoted annealing follows second-order reaction kinetics. Last, Rad59 enhances Rad52-mediated DNA annealing at increased NaCl concentrations, both in the absence and presence of RPA. These results suggest that Rad59 performs different functions in the recombination process, and should be more accurately viewed as a Rad52 paralogue.
Section of Microbiology, Center for Genetics and Development, Division of Biological Sciences, University of California, Davis, California 95616-8665, USA.
Yun
Y
Wu
Tomohiko
T
Sugiyama
Stephen C
SC
Kowalczykowski
D001483:Base Sequence; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005800:Genes, Fungal; D007700:Kinetics; D051721:Rad52 DNA Repair and Recombination Protein / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
D004271:DNA, Fungal; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; C497197:RAD52 protein, S cerevisiae; C400213:RAD59 protein, S cerevisiae; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins