Synergistic actions of Rad51 and Rad52 in recombination and DNA repair

Article metrics


In the yeast Saccharomyces cerevisiae, mutations in the genes RAD51 or RAD52 result in severe defects in genetic recombination and the repair of double-strand DNA breaks. These genes, and others of the RAD52 epistasis group (RAD50, RAD54, RAD55, RAD57, RAD59, MRE11 and XRS2), were first identified by their sensitivity to X-rays1. They were subsequently shown to be required for spontaneous and induced mitotic recombination, meiotic recombination, and mating-type switching (reviewed in ref. 2). Human homologues of RAD50, RAD51, RAD52, RAD54 and MRE11 have been identified3,4,5,6. Targeted disruption of the murine RAD51 gene results in an embryonic lethal phenotype, indicating that Rad51 protein is required during cell proliferation7,8. Biochemical studies have shown that human RAD51 encodes a protein of relative molecular mass 36,966 (hRad51) that promotes ATP-dependent homologous pairing and DNA strand exchange9,10,11. As a structural and functional homologue of the RecA protein from Escherichia coli3,9,12, hRad51 is thought to play a central role in recombination. Yeast Rad51 has been shown to interact with Rad52 protein13,14,15, as does the human homologue16. Here we show that hRad52 stimulates homologous pairing by hRad51. The DNA-binding properties of hRad52 indicate that Rad52 is involved in an early stage of Rad51-mediated recombination.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Purification of recombinant human Rad52 protein from E.coli.
Figure 2: Stimulation of hRad51-mediated joint molecule formation by hRad52.
Figure 3: DNA-binding properties of hRad52.
Figure 4: hRad52 is involved in the early stages of hRad51-mediated pairing reactions.


  1. 1

    Game, J. C. & Mortimer, R. K. Agenetic study of X-ray sensitive mutants in yeast. Mutat. Res. 24, 281–292 (1974).

  2. 2

    Petes, T. D., Malone, R. E. & Symington, L. S. in The Molecular and Cellular Biology of the Yeast Saccharomyces: Genome Dynamics, Protein Synthesis and Energetics (Broach, J., Jones, E. & Pringle, J., eds) 407–521 (Cold Spring Harbor Laboratory Press, NY, 1991).

  3. 3

    Shinohara, al. Cloning of human, mouse and fission yeast recombination genes homologous to RAD51 and recA. Nature Genet. 4, 239–243 (1993).

  4. 4

    Muris, D. F. al. Cloning of human and mouse genes homologous to RAD52, a yeast gene involved in DNA repair and recombination. Mutat. Res. DNA Repair 315, 295–305 (1994).

  5. 5

    Kanaar, al. Human and mouse homologs of the Saccharomyces cerevisiae RAD54 DNA repair gene: Evidence for functional conservation. Curr. Biol. 6, 828–838 (1996).

  6. 6

    Dolganov, G. al. Human Rad50 is physically associated with human Mre11: identification of a conserved mutliprotein complex implicated in recombinational DNA repair. Mol. Cell. Biol. 16, 4832–4841 (1996).

  7. 7

    Tsuzuki, al. Targeted disruption of the RAD51 gene leads to lethality in embryonic mice. Proc. Natl Acad. Sci. USA 93, 6236–6240 (1996).

  8. 8

    Lim, D. S. & Hasty, P. Amutation in mouse RAD51 results in an early embryonic lethal that is suppressed by a mutation in p53. Mol. Cell. Biol. 16, 7133–7143 (1996).

  9. 9

    Baumann, P., Benson, F. E. & West, S. C. Human Rad51 protein promotes ATP-dependent homologous pairing and strand transfer reactions in vitro. Cell 87, 757–766 (1996).

  10. 10

    Baumann, P. & West, S. C. The human Rad51 protein: polarity of strand transfer and stimulation by hRP-A. EMBO J. 16, 5198–5206 (1997).

  11. 11

    Gupta, R. C., Bazemore, L. R., Golub, E. I. & Radding, C. M. Activities of human recombination protein Rad51. Proc. Natl Acad. Sci. USA 94, 463–468 (1997).

  12. 12

    Benson, F. E., Stasiak, A. & West, S. C. Purification and characterisation of the human Rad51 protein, an analogue of E. coli RecA. EMBO J. 13, 5764–5771 (1994).

  13. 13

    Milne, G. T. & Weaver, D. T. Dominant-negative alleles of RAD52 reveal a DNA repair recombination complex including Rad51 and Rad52. Genes Dev. 7, 1755–1765 (1993).

  14. 14

    Hays, S. L., Firmenich, A. A. & Berg, P. Complex formation in yeast double-strand break repair: participation of Rad51, Rad52, Rad55, and Rad57 proteins. Proc. Natl Acad. Sci. USA 92, 6925–6929 (1995).

  15. 15

    Shinohara, A., Ogawa, H. & Ogawa, T. Rad51 protein involved in repair and recombination in Saccharomyces cerevisiae is a RecA-like protein. Cell 69, 457–470 (1992).

  16. 16

    Shen, Z. Y., Cloud, K. G., Chen, D. J. & Park, M. S. Specific interactions between the human Rad51 and Rad52 proteins. J. Biol. Chem. 271, 148–152 (1996).

  17. 17

    Mortensen, U. H., Bendixen, C., Sunjevaric, I. & Rothstein, R. DNA strand annealing is promoted by the yeast Rad52 protein. Proc. Natl Acad. Sci. USA 93, 10729–10734 (1996).

  18. 18

    Reddy, G., Golub, E. I. & Radding, C. M. Human Rad52 protein promotes single-strand DNA annealing followed by branch migration. Mutat. Res. 377, 53–59 (1997).

  19. 19

    Bishop, D. K. RecA homologs Dmc1 and Rad51 interact to form multiple nuclear complexes prior to meiotic chromosome synapsis. Cell 79, 1081–1092 (1994).

  20. 20

    Plug, A. W., Xu, J. H., Reddy, G., Golub, E. I. & Ashley, T. Presynaptic association of Rad51 protein with selected sites in meiotic chromatin. Proc. Natl Acad. Sci. USA 93, 5920–5924 (1996).

  21. 21

    Barlow, A. L., Benson, F. E., West, S. C. & Hultén, M. A. Distribution of Rad51 recombinase in human and mouse spermatocytes. EMBO J. 16, 5207–5215 (1997).

  22. 22

    Moens, P. al. Rad51 immunocytology in rat and mouse spermatocytes and oocytes. Chromosoma 106, 207–215 (1997).

  23. 23

    Hashimoto, K. & Yonesaki, T. The characterization of a complex of three bacteriophage T4 recombination proteins, uvsX protein, uvsY protein and gene 32 protein, on single-stranded DNA. J. Biol. Chem. 266, 4883–4888 (1991).

  24. 24

    Kodadek, T., Gan, D.-C. & Stemke-Hale, K. The phage T4 UvsY recombination protein stabilizes presynaptic filaments. J. Biol. Chem. 264, 16451–16457 (1989).

  25. 25

    Yonesaki, T. & Minagawa, T. Synergistic action of three recombination gene products of bacteriophage T4, uvsX, uvsY, and gene 32 proteins. J. Biol. Chem. 264, 7814–7820 (1989).

  26. 26

    Baumann, P., Benson, F. E., Hajibagheri, N. & West, S. C. Purification of human Rad51 protein by selective spermidine precipitation. Mutat. Res. DNA Repair 384, 65–72 (1997).

Download references


We thank O. Bezzubova and J.-M. Buerstedde for plasmid pCR52; E. Van Dyck for contributions relating to the DNA-binding assays; and D. Bishop, A. Shinohara, T. Ogawa, P. Sung and S.Kowalczykowski for information relating to the actions of yeast Rad52 before publication. This work was supported by the ICRF and HFSPO.

Author information

Correspondence to Stephen C. West.

Rights and permissions

Reprints and Permissions

About this article

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.