In addition to 3'- to 5'-exonuclease and 3'-phosphatase activities, ExoA was shown to make single-strand breaks at apurinic sites in DNA. Exonucleolytic cleavage in the 3'- to 5'-direction to yield nucleoside 5'-phosphates. Probably binds two magnesium or manganese ions per subunit. Belongs to the DNA repair enzymes AP/ExoA family.