Interaction with RPA is necessary for Rad52 repair center formation and for its mediator activity.
Homologous recombination (HR) is a major DNA repair pathway and therefore essential for maintaining the integrity of the genome. HR is catalyzed by proteins encoded by genes of the RAD52 epistasis group, including the recombinase Rad51 and its mediator Rad52. HR proteins fused with green fluorescent protein form foci at damaged DNA reflecting the assembly of repair centers that harbor a high concentration of repair proteins. Rad52 mediates the recruitment of Rad51 and other HR proteins to DNA damage. To understand the mechanism for the assembly of Rad52-dependent DNA repair centers, we used a mutational strategy to identify a Rad52 domain essential for its recruitment to DNA repair foci. We present evidence to implicate an acidic domain in Rad52 in DNA repair focus formation. Mutations in this domain confer marked DNA damage sensitivity and recombination deficiency. Importantly, these Rad52 mutants are specifically compromised for interaction with the single-stranded DNA-binding factor RPA. Based on these findings, we propose a model where Rad52 displaces RPA from single-stranded DNA using the acidic domain as a molecular lever.
Plate
Iben
I
Center for Microbial Biotechnology, Technical University of Denmark, Lyng by 2800, Denmark.
Hallwyl
Swee C L
SC
Shi
Idina
I
Krejci
Lumir
L
Müller
Christian
C
Albertsen
Line
L
Sung
Patrick
P
Mortensen
Uffe H
UH
D000595:Amino Acid Sequence; D004249:DNA Damage; D004260:DNA Repair; D004843:Epistasis, Genetic; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D051135:Rad51 Recombinase / Q000378:metabolism; D051721:Rad52 DNA Repair and Recombination Protein / Q000737:chemistry / Q000378:metabolism*; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques
D051721:Rad52 DNA Repair and Recombination Protein; D051135:Rad51 Recombinase