Luo, Shih-ChiShih-ChiLuoYeh, Min-ChiMin-ChiYehLien, Yu-HsiangYu-HsiangLienYeh, Hsin-YiHsin-YiYehSiao, Huei-LunHuei-LunSiaoTu, I-PingI-PingTuHUNG-YUAN CHIHo, Meng-ChiaoMeng-ChiaoHo2023-09-042023-09-042023-08-172041-1723https://scholars.lib.ntu.edu.tw/handle/123456789/634920ATP-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.en[SDGs]SDG3journal article10.1038/s41467-023-40672-5375918532-s2.0-85168273590https://api.elsevier.com/content/abstract/scopus_id/85168273590