title: Roles of C-Terminal Region of Yeast and Human Rad52 in Rad51-Nucleoprotein Filament Formation and ssDNA Annealing.
abstract: Yeast Rad52 (yRad52) has two important functions at homologous DNA recombination (HR); annealing complementary single-strand DNA (ssDNA) molecules and recruiting Rad51 recombinase onto ssDNA (recombination mediator activity). Its human homolog (hRAD52) has a lesser role in HR, and apparently lacks mediator activity. Here we show that yRad52 can load human Rad51 (hRAD51) onto ssDNA complexed with yeast RPA in vitro. This is biochemically equivalent to mediator activity because it depends on the C-terminal Rad51-binding region of yRad52 and on functional Rad52-RPA interaction. It has been reported that the N-terminal two thirds of both yRad52 and hRAD52 is essential for binding to and annealing ssDNA. Although a second DNA binding region has been found in the C-terminal region of yRad52, its role in ssDNA annealing is not clear. In this paper, we also show that the C-terminal region of yRad52, but not of hRAD52, is involved in ssDNA annealing. This suggests that the second DNA binding site is required for the efficient ssDNA annealing by yRad52. We propose an updated model of Rad52-mediated ssDNA annealing.
authors.affiliation: Department of Biological Sciences, Ohio University, Athens, Ohio, United States of America.
authors.forename: Nilesh V
authors.initials: NV
authors.lastname: Khade
authors.affiliation: Department of Biological Sciences, Ohio University, Athens, Ohio, United States of America.
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Sugiyama
mesh_terms: D020029:Base Pairing / Q000502:physiology; D001665:Binding Sites; D004277:DNA, Single-Stranded / Q000378:metabolism*; D006801:Humans; D009698:Nucleoproteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs / Q000502:physiology*; D055503:Protein Multimerization; D051135:Rad51 Recombinase / Q000737:chemistry / Q000378:metabolism*; D051721:Rad52 DNA Repair and Recombination Protein / Q000737:chemistry* / Q000378:metabolism; D011995:Recombination, Genetic; D059767:Recombinational DNA Repair; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000378:metabolism
chemical_list: D004277:DNA, Single-Stranded; D009698:Nucleoproteins; C497197:RAD52 protein, S cerevisiae; C497194:RAD52 protein, human; D051721:Rad52 DNA Repair and Recombination Protein; D029701:Saccharomyces cerevisiae Proteins; D051135:Rad51 Recombinase