N-Acetylmuramic acid
N-Acetylmuramic acid (NAM or MurNAc) is an organic compound with the formula C11H19NO8. It is a building block of peptidoglycan, the main component of most bacterial cell walls. In peptidoglycan, NAM links to N-acetylglucosamine (GlcNAc) and is cross-linked to other NAM units by short peptides.
NAM has a lactic acid side chain that allows it to carry a five-amino-acid peptide (a pentapeptide) to help form the rigid mesh of the cell wall. A typical attached pentapeptide is L-alanyl-D-isoglutaminyl-L-lysyl-D-alanyl-D-alanine.
NAM is made in the cell’s cytoplasm from N-acetylglucosamine through a biosynthetic pathway that involves phosphoenolpyruvate.
Antibiotics can interfere with NAM production or with the cross-linking between NAM and GlcNAc, helping to stop bacteria from growing. Because NAM and GlcNAc are essential for bacterial walls, they are important targets in antibiotic research.
This page was last edited on 2 February 2026, at 16:53 (CET).