The endopeptidase activity cleaves the bacterial peptidoglycan between D-alanine and L-alanine (PubMed:15256551, PubMed:17021237). The N-acetyl-muramidase activity cleaves between N-acetylmuramic acid and N-acetylglucosamine bonds (PubMed:17021237). Hydrolysis of (1->4)-beta-linkages between N-acetylmuramic acid and N-acetyl-D-glucosamine residues in a peptidoglycan and between N-acetyl-D-glucosamine residues in chitodextrins. Ca++ enhances the activity of the enzyme. Optimum pH is 5.5-6.0. A CHAP domain is present at the N-terminus and is associated with the endopeptidase activity (PubMed:15256551). The CHAP domain is responsible for nearly all the cell lysis activity (PubMed:16820517). An Acm glycosidase domain is located in the central part of the protein and is associated with the muramidase activity (PubMed:15256551). The Acm domain seems to require the SH3b domain for activity (PubMed:16820517). Belongs to the glycosyl hydrolase 25 family.