Component of the cylindrical core that assembles on the inner surface of the capsid during capsid formation and plays a role in viral DNA ejection into the host cell. The inner core is composed of stacked rings of gp14, gp15 and gp16 proteins. Following binding to the host cell surface, the internal core is diassembled and gp16 is ejected along with gp14 and gp15 into the infected cell. Gp16 probably inserts in the host inner membrane and remains associated with gp15. The gp15-gp16 complex binds to both the viral DNA and the host inner membrane, probably escorting the leading end of the genome through the periplasm and controlling the extend of DNA translocated into the host cell. Functions as an exolysin that catalyzes the cleavage of the glycosidic bonds between N-acetylmuramic acid and N-acetylglucosamine residues in peptidoglycans allowing the local digestion of the bacterial peptidoglycan wall. Exolytic cleavage of the (1->4)-beta-glycosidic linkage between N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) residues in peptidoglycan, from either the reducing or the non-reducing ends of the peptidoglycan chains, with concomitant formation of a 1,6-anhydrobond in the MurNAc residue. Homotetramer. Interacts with gp15; after ejection the gp15-gp16 complex composed of a gp15 octamer and a gp16 tetramer probably binds both the viral DNA and the host inner membrane. The gp15-gp16 complex spans the periplasm and the cytoplasmic membrane. The N-terminus contains the transglycosylase activity (Potential). The C-terminus is essential for the viral DNA translocation into the host cytoplasm. Belongs to the transglycosylase Slt family.