Hydrolyzes the cross-linked dimers tetrapentapeptide (D45) and tetratetrapeptide (D44). Removes the terminal D-alanine from muropeptides and disaccharide pentapeptide M5 with a C-terminal D-Ala-D-Ala dipeptide. Associated with recycling and remodeling of peptidoglycan (PG). Also displays a low beta-lactamase activity. Inhibited by cefmetazole. Disruption is viable and exhibits no overt growth defects, but produces morphologically aberrant cells, particularly in cell filaments induced by aztreonam. Belongs to the beta-lactamase family. Truncated N-terminus.