Figure 3.

Schematic representation of the basic structure of bacterial cell wall peptidoglycan with possible catalytic activities of endolysins indicated. A sub-class of Glycosidases, N-acetyl-β-D-muramidases cleave the β-1,4 bonds between NAM (N-acetylmuramic acid) and NAG (N-acetylglucosamines), and N-acetyl-β-D-glucosidases cleave the β-1,4 bonds between NAG and NAM residues. N-acetylmuramoyl-L-alanine amidases which are amidases cleave the amide bonds between NAM and L-alanine. Endopeptidases cleave interpeptide and stem peptide–interpeptide bridges.