Local structural dynamics of Rad51 protomers revealed by cryo-electron microscopy of Rad51-ssDNA filaments.

ABSTRACT: Homologous recombination (HR) is a high-fidelity repair mechanism for double-strand breaks. Rad51 is the key enzyme that forms filaments on single-stranded DNA (ssDNA) to catalyze homology search and DNA strand exchange in recombinational DNA repair. In this study, we employed single-particle cryogenic electron microscopy (cryo-EM) to ascertain the density map of the wild-type budding yeast Rad51-ssDNA filament bound to ADP-AlF3, achieving a resolution of 2.35 Å without imposing helical symmetry. The model assigned 6 Rad51 protomers, 24 nt of DNA, and 6 bound ADP-AlF3. It shows 6-fold symmetry implying monomeric building blocks, unlike the structure of the Rad51-I345T mutant filament with three-fold symmetry implying dimeric building blocks, for which the structural comparisons provide a s

SUBMITTER: Liu J 

PROVIDER: S-EPMC11788929 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature