D160N participates in base excision repair with similar efficiency as WT. WCE from Pol β-deficient MEFs was incubated with the UDG-treated LPSD DNA substrate. Addition of purified Pol β enzyme for 2, 5 or 20 min results in dCTP incorporation, followed by DNA ligation by WCE enzymes to form fully repaired product. After 2 min, WT and D160N repair 35% of the DNA substrate. By 20 min, WT repairs 86% and D160N repairs 87% of the DNA substrate. Lane 1, annealed DNA substrate; Lane 2, UDG-treated DNA substrate; Lane 3, UDG-treated DNA incubated with WCE; Lanes 4–6, UDG-treated DNA substrate incubated with WCE and WT Pol β for 2, 5 and 20 min respectively; Lanes 7–9, UDG-treated DNA substrate incubated with WCE and D160N for 2, 5 and 20 min respectively.