The non-homologous end joining (NHEJ) pathway is one method by which double stranded breaks in chromosomal DNA are repaired. Ku is a component of a multi-protein complex that is involved in the NHEJ. Ku has affinity for DNA ends and recruits the DNA-dependent protein kinase catalytic subunit (DNA-PKcs). This domain is found at the C terminal of Ku which binds to DNA-PKcs [1].

1: The 3D solution structure of the C-terminal region of Ku86 (Ku86CTR). Harris R, Esposito D, Sankar A, Maman JD, Hinks JA, Pearl LH, Driscoll PC; J Mol Biol. 2004;335:573-582. PMID:14672664