Catalyzes the removal of dipeptides from the N-terminus of oligopeptides. Shows a strict specificity for acidic residues (Asp or Glu) in the P1 position, and has a hydrophobic residue preference at the P2 position. Is likely involved in amino acid metabolism and bacterial growth/survival of asaccharolytic P.endodontalis, that utilizes amino acids from extracellular proteinaceous nutrients as energy and carbon sources. Enzyme activity is completely blocked by diisopropyl-fluorophosphates, moderately by phenylmethylsulfonyl fluoride (PMSF) and 4-(2-methyl)benzenesulfonyl fluoride, and slightly by pepstatin in vitro. Optimum pH is 7.0. Is observed in both cell-associated and soluble extracellular forms. Belongs to the peptidase S46 family.