Recombinant Human DNA Repair Protein XRCC4 (hXRCC4) Fragment (aa 1-205) is a high-purity, stable protein fragment designed for structural and biochemical studies. This soluble unit retains key functional properties, making it ideal for investigating DNA non-homologous end joining (NHEJ), double-strand break repair, and V(D)J recombination mechanisms.

The full-length DNA repair protein XRCC4 is a core factor in the DNA non-homologous end joining (NHEJ) pathway, essential for repairing double-strand breaks and facilitating V(D)J recombination. It functions as a scaffold protein that recruits other repair factors to DNA damage sites and forms helical filaments with NHEJ1/XLF to bridge broken DNA ends, maintaining their proximity and accessibility for processing. XRCC4 stabilizes and enhances the activity of DNA ligase IV (LIG4), promoting the ligation step in DSB repair. Additionally, upon caspase-3 cleavage, the C-terminal fragment translocates to the cytoplasm, where it activates XKR4's phospholipid s