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Structure of a multisubunit complex that promotes DNA branch migration


THE RuvA and RuvB proteins of Escherichia coli, which are induced in response to DNA damage, are important in the formation of heteroduplex DNA during genetic recombination and related recombinational repair processes1. In vitro studies show that RuvA binds Holliday junctions2–5 and acts as a specificity factor that targets the RuvB ATPase, a hexameric ring protein6–7, to the junction. Together, RuvA and RuvB promote branch migration, an ATP-dependent reaction that increases the length of the heteroduplex DNA3,8–10. Electron microscopic visualization of RuvAB now provides a new insight into the mechanism of this process. We observe the formation of a tripartite protein complex in which RuvA binds the crossover and is sandwiched between two hexameric rings of RuvB. The Holliday junction within this complex adopts a square-planar structure. We propose a molecular model for branch migration, a unique feature of which is the role played by the two oppositely oriented RuvB ring motors.

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  1. West, S. C. Cell 76, 9–15 (1994).

    Article  CAS  Google Scholar 

  2. Parsons, C. A., Tsaneva, I., Lloyd, R. G. & West, S. C. Proc. natn. Acad. Sci. U.S.A. 89, 5452–5456 (1992).

    Article  ADS  CAS  Google Scholar 

  3. Parsons, C. A. & West, S. C. J. molec. Biol. 232, 397–405 (1993).

    Article  CAS  Google Scholar 

  4. Iwasaki, H., Takahagi, M., Nakata, A. & Shinagawa, H. Genes Dev. 6, 2214–2220 (1992).

    Article  CAS  Google Scholar 

  5. Hiom, K. & West, S. C. Cell 80, 787–793 (1995).

    Article  CAS  Google Scholar 

  6. Mitchell, A. H. & West, S. C. J. molec. Biol. 243, 208–215 (1994).

    Article  CAS  Google Scholar 

  7. Stasiak, A. et al. Proc. natn. Acad. Sci. U.S.A. 91, 7618–7622 (1994).

    Article  ADS  CAS  Google Scholar 

  8. Tsaneva, I. R., Müller, B. & West, S. C. Cell 69, 1171–1180 (1992).

    Article  CAS  Google Scholar 

  9. Müller, B., Tasaneva, I. R. & West, S. C. J. biol. Chem. 268, 17179–17184 (1993).

    PubMed  Google Scholar 

  10. Shiba, T., Iwasaki, H., Nakata, A. & Shinagawa, H. Proc. natn. Acad. Sci. U.S.A. 88, 8445–8449 (1991).

    Article  ADS  CAS  Google Scholar 

  11. Tsaneva, I. R., Illing, G. T., Lloyd, R. G. & West, S. C. Molec. gen. Genet. 235, 1–10 (1992).

    Article  CAS  Google Scholar 

  12. Duckett, D. R. et al. Cell 55, 79–89 (1988).

    Article  CAS  Google Scholar 

  13. Duckett, D. R., Murchie, A. I. H. & Lilley, D. M. J. EMBO J. 9, 583–590 (1990).

    Article  CAS  Google Scholar 

  14. Lilley, D. M. J. & Clegg, R. M. A. Rev. Biophys. biomolec. Struct. 22, 299–328 (1993).

    Article  CAS  Google Scholar 

  15. Tsaneva, I. R., Müller, B. & West, S. C. Proc. natn. Acad. Sci. U.S.A. 90, 1315–1319 (1993).

    Article  ADS  CAS  Google Scholar 

  16. Adams, D. E. & West, S. C. J. molec. Biol. 247, 404–417 (1995).

    Article  CAS  Google Scholar 

  17. Müller, B., Burdett, I. & West, S. C. EMBO J. 11, 2685–2693 (1992).

    Article  Google Scholar 

  18. Panyutin, I. G. & Hsieh, P. Proc. natn. Acad. Sci. U.S.A. 91, 2021–2025 (1994).

    Article  ADS  CAS  Google Scholar 

  19. Iype, L. E., Wood, E. A., Inman, R. B. & Cox, M. M. J. biol. Chem. 269, 24967–24978 (1994).

    CAS  PubMed  Google Scholar 

  20. Dean, F. B., Borowiec, J. A., Eki, T. & Hurwitz, J. J. biol. Chem. 267, 14129–14137 (1992).

    CAS  Google Scholar 

  21. Wessel, R., Schwizer, J. & Stahl, H. J. Virol. 66, 804–815 (1992).

    CAS  PubMed  PubMed Central  Google Scholar 

  22. McCulloch, R., Coggins, L. W., Colloms, S. D. & Sherratt, D. J. EMBO J. 13, 1844–1855 (1994).

    Article  CAS  Google Scholar 

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Parsons, C., Stasiak, A., Bennett, R. et al. Structure of a multisubunit complex that promotes DNA branch migration. Nature 374, 375–378 (1995).

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