Figure1: (A) Structure of the peptidoglycan repeat unit composed of N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc) linked via a β-1,4 glycosidic linkage. Off of the C-3 lactyl moiety of MurNAc is attached a pentapeptide which is involved in cross-linking adjacent peptidoglycan strands. (B) Proposed mechanism of action of lytic transglycosylases.