Interaction of human rad51 recombination protein with single-stranded DNA binding protein, RPA.
Replication protein A (RPA), a heterotrimeric single-stranded DNA binding protein, is required for recombination, and stimulates homologous pairing and DNA strand exchange promoted in vitro by human recombination protein HsRad51. Co-immunoprecipitation revealed that purified RPA interacts physically with HsRad51, as well as with HsDmc1, the homolog that is expressed specifically in meiosis. The interaction with HsRad51 was mediated by the 70 kDa subunit of RPA, and according to experiments with deletion mutants, this interaction required amino acid residues 169-326. In exponentially growing mammalian cells, 22% of nuclei showed foci of RPA protein and 1-2% showed foci of Rad51. After gamma-irradiation, the percentage of cells with RPA foci increased to approximately 50%, and those with Rad51 foci to 30%. All of the cells with foci of Rad51 had foci of RPA, and in those cells the two proteins co-localized in a high fraction of foci. The interactions of human RPA with Rad51, replication proteins and DNA are suited to the linking of recombination to replication.
Golub
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Department of Genetics and Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA. golub@biomed.med.yale.edu
Gupta
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Haaf
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Wold
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Radding
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D000818:Animals; D002478:Cells, Cultured; D004277:DNA, Single-Stranded / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D005720:Gamma Rays; D006801:Humans; D051379:Mice; D008970:Molecular Weight; D010446:Peptide Fragments / Q000378:metabolism; D010449:Peptide Mapping; D011233:Precipitin Tests; D051135:Rad51 Recombinase; D051381:Rats; D011995:Recombination, Genetic; D051716:Replication Protein A
D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D010446:Peptide Fragments; C497167:RPA1 protein, human; D051716:Replication Protein A; C497168:Rpa1 protein, mouse; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; C495154:Rad51 protein, mouse; C495155:Rad51 protein, rat