DNA-(apurinic or apyrimidinic site) lyase 2 (APEX2)

Function as a weak apurinic/apyrimidinic (AP) endodeoxyribonuclease from the DNA base excision repair (BER) pathway of DNA lesions induced by oxidative and alkylating agents. Initiates repair of AP sites in DNA by catalyzing hydrolytic incision of the phosphodiester backbone immediately adjacent to the harm, generating a single-strand break with 5'-deoxyribose phosphate and 3'-hydroxyl ends.

Displays also double-stranded DNA 3'-5' exonuclease, 3'-phosphodiesterase activities. Shows robust 3'-5' exonuclease activity on 3'-recessed heteroduplex DNA and is able to remove mismatched nucleotides preferentially.