(A). Overlay of HPLC profiles of muropeptides obtained from C. crescentus cultures grown in the indicated media. CAA, casamino acids; empty arrowheads, Penta(Gly)-containing muropeptide peaks; filled arrowheads, peak corresponding to the PentaTri muropeptide species. (B). Relative representation (molar percentage) of each muropeptide species in PG digests obtained from C. crescentus cultures grown in the indicated media. Red rectangles denote glycine-containing species; Tri, GlcNAc-MurNAc-l-Ala-d-γ-Glu-m-Dap ; Tetra, GlcNAc-MurNAc-l-Ala-d-γ-Glu-m-Dap-d-Ala; Penta, GlcNAc-MurNAc-l-Ala-d-γ-Glu-m-Dap-d-Ala-d-Ala; Penta(Gly), GlcNAc-MurNAc-l-Ala-d-γ-Glu-m-Dap-d-Ala-Gly; Anh, 1,6-anhydro- MurNAc; (D,D), m-Dap-D-Ala crosslink; (L,D), m-Dap-m-Dap crosslink. Bars represent averages ± standard deviation for two (M2G, M2G + 0.2 mM Gly, M2G + 2 mM Gly) or three (M2G + 0.1% CAA) samples analyzed. (C). Summary of the composition of C. crescentus PG digests obtained from C. crescentus cultures grown in the indicated media. Major PG characteristics are shown, namely the total degree of crosslinkage, the relative amounts of differentially crosslinked muropeptide classes (monomers, dimers, trimers and tetramers), side chain types (Tri, l-Ala-d-γ-Glu-m-Dap ; Tetra, l-Ala-d-γ-Glu-m-Dap-d-Ala; Penta(Ala), l-Ala-d-γ-Glu-m-Dap-d-Ala-d-Ala; Penta(Gly), l-Ala-d-γ-Glu-m-Dap-d-Ala-Gly), or chain ends (anhydro, 1,6-anhydro-MurNAc ). The red rectangle highlights the relative amounts of the Penta(Gly) side chain. Bars are as in (B).