Download MendeleyStructural basis for cooperative ssDNA binding by bacteriophage protein filament P12.
Trager, L.K., Degen, M., Pereira, J., Durairaj, J., Teixeira, R.D., Hiller, S., Huguenin-Dezot, N.(2025) Nucleic Acids Res 53
- PubMed: 40052821
- DOI: https://doi.org/10.1093/nar/gkaf132
- Primary Citation of Related Structures:
9GFQ, 9I86 - PubMed Abstract:
Protein-primed DNA replication is a unique mechanism, bioorthogonal to other known DNA replication modes. It relies on specialised single-stranded DNA (ssDNA)-binding proteins (SSBs) to stabilise ssDNA intermediates by unknown mechanisms. Here, we present the structural and biochemical characterisation of P12, an SSB from bacteriophage PRD1. High-resolution cryo-electron microscopy reveals that P12 forms a unique, cooperative filament along ssDNA. Each protomer binds the phosphate backbone of 6 nucleotides in a sequence-independent manner, protecting ssDNA from nuclease degradation. Filament formation is driven by an intrinsically disordered C-terminal tail, facilitating cooperative binding. We identify residues essential for ssDNA interaction and link the ssDNA-binding ability of P12 to toxicity in host cells. Bioinformatic analyses place the P12 fold as a distinct branch within the OB-like fold family. This work offers new insights into protein-primed DNA replication and lays a foundation for biotechnological applications.
Organizational Affiliation:
Department of Biosystems Science and Engineering, ETH Zurich, Schanzenstrasse 44, 4056 Basel, Switzerland.
