Structure of Bacillus subtilis Ku-mediated DNA synaptic complex.

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 hom

SUBMITTER: Kim WJ 

PROVIDER: S-EPMC12784961 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature