Figure 1.

Cleavage sites of the different enzymatic classes of EADs on the primary structures of two common peptidoglycan types. (A) peptidoglycan chemotype A1γ is the most common in Gram-negative bacteria; (B) peptidoglycan chemotype A3, either α or γ depending on the presence of L-Lys or mDAP in the third position of the peptide subunit, is a type example for Gram-positive bacteria such as Staphylococcus aureus [10]. The colored scissors indicate cleavage sites of different classes of EADs. GlcNAc and MurNAc in the glycan strands of each structure refer to N-acetylglucosamine and N-acetylmuramic acid, respectively.