Rad54 protein is targeted to pairing loci by the Rad51 nucleoprotein filament

Mol Cell. 2000 Sep;6(3):583-92. doi: 10.1016/s1097-2765(00)00057-5.


Rad51 and Rad54 proteins are important for the repair of double-stranded DNA (dsDNA) breaks by homologous recombination in eukaryotes. Rad51 assembles on single-stranded DNA (ssDNA) to form a helical nucleoprotein filament that performs homologous pairing with dsDNA; Rad54 stimulates this pairing substantially. Here, we demonstrate that Rad54 acts in concert with the mature Rad51-ssDNA filament. Enhancement of DNA pairing by Rad54 is greatest at an equimolar ratio relative to Rad51 within the filament. Reciprocally, the Rad51-ssDNA filament enhances both the dsDNA-dependent ATPase and the dsDNA unwinding activities of Rad54. We conclude that Rad54 participates in the DNA homology search as a component of the Rad51-nucleoprotein filament and that the filament delivers Rad54 to the dsDNA pairing locus, thereby linking the unwinding of potential target DNA with the homology search process.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases / metabolism
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • DNA Helicases
  • DNA Repair / drug effects
  • DNA Repair / physiology*
  • DNA Repair Enzymes
  • DNA, Single-Stranded / metabolism*
  • DNA, Superhelical / metabolism
  • DNA-Binding Proteins / metabolism*
  • DNA-Binding Proteins / pharmacology
  • Escherichia coli
  • Fungal Proteins / metabolism*
  • Fungal Proteins / pharmacology
  • Humans
  • Rad51 Recombinase
  • Saccharomyces cerevisiae
  • Saccharomyces cerevisiae Proteins*
  • Species Specificity


  • DNA, Single-Stranded
  • DNA, Superhelical
  • DNA-Binding Proteins
  • Fungal Proteins
  • Saccharomyces cerevisiae Proteins
  • RAD51 protein, S cerevisiae
  • RAD51 protein, human
  • Rad51 Recombinase
  • Adenosine Triphosphatases
  • RAD54 protein, S cerevisiae
  • DNA Helicases
  • DNA Repair Enzymes