Endonuclease that plays a role in DNA repair (By similarity). Cleaves phosphodiester bonds on the 5' side of apurinic or apyrimidinic sites (AP sites) (By similarity). In addition to endonuclease activity, the ASFV enzyme has a proofreading 3'-5' exonuclease activity that is considerably more efficient in the elimination of a mismatch than in that of a correctly paired base (By similarity). Displays 3'-phosphatase and 3'-repair diesterase activities (By similarity). The single nucleotide gaps generated by the AP endonuclease are filled by the viral AP endonuclease and DNA ligase (Probable). Binds 3 Zn(2+) ions. The early enzyme is localized in the nucleus and the cytoplasm, while the late protein is found only in the cytoplasm (By similarity). Found in association with viral nucleoid (By similarity). Expressed in the early phase of the viral replicative cycle and accumulates at later times. Consistent with its intracellular location, ASFV encodes its own replicative DNA polymerase and three base excision repair enzymes: a class II AP endonuclease, the repair polymerase Pol X, and an ATP-dependent DNA ligase. During infection, the protein is expressed at early times and accumulates at later times. Belongs to the AP endonuclease 2 family.