Figure 7
L. plantarum PG structure and modification of muropeptide content resulting from PGH inactivation. Muropeptides that disappear or are strongly reduced resulting from the inactivation of either Acm2 (A) or LytA (B) are boxed. M, MurNAc; G, GlcNAc; Disaccharide, GM. M-Tetra, MurNAc-tetrapeptide; M-Tetra-GM-Tri, MurNAc-tetrapeptide crosslinked to a disaccharide-tripeptide; GM-di, disaccharide-dipeptide; GM-Tri-(Ala-mDAP), disaccharide-tripeptide crosslinked to the dipeptide L-Ala-mDAP from a second peptide stem; GM-Tetra-(Ala-mDAP), disaccharide-tetrapeptide crosslinked to the dipeptide L-Ala-mDAP from a second peptide stem. Cleavage sites of PGHs are indicated by arrows: M (boldface), mutanolysin (N-acetylmuramidase); Acm2-, absence of cleavage by a N-acetylglucosaminidase in the PG of the Acm2-deficient strain; and LytA-, absence of cleavage by a γ-D-Glu-mDAP muropeptidase in the PG of the LytA-deficient strain.