Download MendeleyA RAD51-ADP double filament structure unveils the mechanism of filament dynamics in homologous recombination.
Luo, S.C., Yeh, M.C., Lien, Y.H., Yeh, H.Y., Siao, H.L., Tu, I.P., Chi, P., Ho, M.C.(2023) Nat Commun 14: 4993-4993
- PubMed: 37591853
- DOI: https://doi.org/10.1038/s41467-023-40672-5
- Primary Citation of Related Structures:
8GYK - PubMed Abstract:
ATP-dependent RAD51 recombinases play an essential role in eukaryotic homologous recombination by catalyzing a four-step process: 1) formation of a RAD51 single-filament assembly on ssDNA in the presence of ATP, 2) complementary DNA strand-exchange, 3) ATP hydrolysis transforming the RAD51 filament into an ADP-bound disassembly-competent state, and 4) RAD51 disassembly to provide access for DNA repairing enzymes. Of these steps, filament dynamics between the ATP- and ADP-bound states, and the RAD51 disassembly mechanism, are poorly understood due to the lack of near-atomic-resolution information of the ADP-bound RAD51-DNA filament structure. We report the cryo-EM structure of ADP-bound RAD51-DNA filaments at 3.1 Å resolution, revealing a unique RAD51 double-filament that wraps around ssDNA. Structural analysis, supported by ATP-chase and time-resolved cryo-EM experiments, reveals a collapsing mechanism involving two four-protomer movements along ssDNA for mechanical transition between RAD51 single- and double-filament without RAD51 dissociation. This mechanism enables elastic change of RAD51 filament length during structural transitions between ATP- and ADP-states.
Organizational Affiliation:
Institute of Biological Chemistry, Academia Sinica, 11529, Taipei, Taiwan.
