Structure of the repeating unit in Peptidoglycan Peptidoglycan is composed of two sugar derivatives, N acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), and a small group of amino acids consisting of L-alanine, D-alanine, D-glutamic acid, and either lysine or diaminopimelic acid DAP) These constituents are baL connected to form a repeating structure, the glycan tetrapeptide ●:4 ●争● 净参●Structure of the Repeating Unit in Peptidoglycan These constituents are connected to form a repeating structure, the glycan tetrapeptide. Peptidoglycan is composed of two sugar derivatives, N￾acetylglucosamine (NAG) and N-acetylmuramic acid (NAM), and a small group of amino acids consisting of L-alanine, D-alanine, D-glutamic acid, and either lysine or diaminopimelic acid (DAP)