Catalyzes the removal of dipeptides from the N-terminus of oligopeptides. Most potently cleaves the synthetic substrate Met-Leu-methylcoumaryl-7-amide (Met-Leu-MCA), followed by Leu-Arg-MCA, while this enzyme does not hydrolyze Gly-Arg-, Gly-Gly-, Lys-Lys-, or Gly-Pro-MCA. Belongs to the peptidase S46 family.