The protein encoded by this gene is the 80-kilodalton subunit of the Ku heterodimer protein which is also known as ATP-dependant DNA helicase II or DNA repair protein XRCC5. Ku is the DNA-binding component of the DNA-dependent protein kinase, and it functions together with the DNA ligase IV-XRCC4 complex in the repair of DNA double-strand break by non-homologous end joining and the completion of V(D)J recombination events. This gene functionally complements Chinese hamster xrs-6, a mutant defective in DNA double-strand break repair and in ability to undergo V(D)J recombination. A rare microsatellite polymorphism in this gene is associated with cancer in patients of varying radiosensitivity.
XRCC5; X-ray repair complementing defective repair in Chinese hamster cells 5 (double-strand-break rejoining); X ray repair complementing defective repair in Chinese hamster cells 5 (double strand break rejoining; Ku autoantigen, 80kD); X-ray repair cross-complementing protein 5; KARP 1; Ku autoantigen; 80kDa; KU80; Ku86; KUB2; TLAA; CTC85; CTCBF; nuclear factor IV; Ku autoantigen, 80kDa; DNA repair protein XRCC5; thyroid-lupus autoantigen; 86 kDa subunit of Ku antigen; lupus Ku autoantigen protein p86; Ku86 autoantigen related protein 1; CTC box-binding factor 85 kDa subunit; ATP-dependent DNA helicase 2 subunit 2; ATP-dependent DNA helicase II 80 kDa subunit; NFIV; KARP1; KARP-1; FLJ39089;
contributes_to 5-deoxyribose-5-phosphate lyase activity; ATP binding; ATP-dependent DNA helicase activity; DNA binding; double-stranded DNA binding; contributes_to double-stranded telomeric DNA binding; helicase activity; hydrolase activity, acting on acid anhydrides; nucleotide binding; protein C-terminus binding; protein binding; telomeric DNA binding; transcription regulatory region DNA binding;