Murein endopeptidase that cleaves the D-alanyl-meso-2,6-diamino-pimelyl amide bond that connects peptidoglycan strands. Likely plays a role in the removal of murein from the sacculus. Binds 2 Zn(2+) ions per subunit. Zn(2+) ion 1 is bound in the active site. Zn(2+) ion 2 is bound at the dimer interface by residues from both subunits. Dimer. Belongs to the peptidase M74 family.