9VNQ
Bacillus Subtilis Ku core homodimer complexed with double strand DNA
Summary for 9VNQ
| Entry DOI | 10.2210/pdb9vnq/pdb |
| EMDB information | 65215 |
| Descriptor | Non-homologous end joining protein Ku, DNA (31-MER) (3 entities in total) |
| Functional Keywords | non homologous end joining, dna bridging, dna binding protein |
| Biological source | Bacillus subtilis More |
| Total number of polymer chains | 6 |
| Total formula weight | 123273.91 |
| Authors | |
| Primary citation | Kim, W.J.,Kim, J.,Jo, M.,Kim, Y.,Kim, M.S. Structure of Bacillus subtilis Ku-mediated DNA synaptic complex. Nucleic Acids Res., 2025 Cited by PubMed Abstract: DNA double-strand breaks (DSBs) pose a severe threat to genomic integrity, and cells rely on two major pathways for repair: homologous recombination and non-homologous end joining (NHEJ). While eukaryotic NHEJ requires a multi-component assembly including the Ku70/80 heterodimer, bacterial NHEJ operates with a simpler toolkit comprising a Ku homodimer and the multifunctional LigD. Despite this simplicity, the mechanism by which broken DNA ends are bridged together has remained unclear in bacterial NHEJ. Here, we present a cryo-electron microscopy structure of the Bacillus subtilis Ku (bsKu)-DNA complex at 2.74 Å resolution, capturing two blunt DNA ends bridged by a Ku protein alone. Supported by further biochemical assays, we propose an integrated model in which oligomeric arrays of Ku homodimers bridge and stabilize two DNA ends, facilitating efficient DSB repair in Bacillus subtilis. This work reveals a bsKu-mediated DNA bridging mechanism distinct from the eukaryotic system and provides critical structural insight into prokaryotic DNA repair. PubMed: 41118517DOI: 10.1093/nar/gkaf1036 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.74 Å) |
Structure validation
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