bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown
Published: Dec. 5, 2024
Abstract Homologous recombination (HR) is essential for the repair of DNA double-strand breaks and restart stalled replication forks. A critical step in HR formation Rad51 nucleofilaments, which perform homology search strand invasion a homologous sequence required synthesis. In yeast Saccharomyces cerevisiae , Rad52 facilitates nucleofilament by mediating loading onto ssDNA counteracting dissociation filaments translocase Srs2. The molecular basis these two functions remains unclear. Our integrative structural analyses Rad51-Rad52 interaction, combining NMR, SAXS, modeling, reveal that an 85-residue segment Rad52, conserved fungi, folds upon binding to broad surface monomer. Notably, it includes FxxA motif BRC repeats BRCA2 at Rad51-Rad51 interface. This mode was validated through extensive set mutations. Using vivo assays functional fluorescent GFP-Rad51 fusion protein, we demonstrated this entire filament formation. These findings highlight how as assembly chaperone, preventing oligomerization, promoting nucleation nucleofilaments on ssDNA, protecting from destabilization
Language: Английский