Fig. 3: Chemical structure of the GAC-peptidoglycan linkage region determined by NMR analysis.
From: PplD is a de-N-acetylase of the cell wall linkage unit of streptococcal rhamnopolysaccharides
Representative structure of the linkage region of GAC anchored to the peptidoglycan layer (top). 1H,31P-HMBC NMR spectrum (a) with a 90 ms delay for the evolution of long-range J couplings shows the key correlation between proton H1 (b) and H2 (d) of GlcN, and the two protons in position 6 of MurNAc (c) to a unique 31P signal at −1.35 ppm, characteristic of a phosphodiester linkage between the two residues. b–d Show the corresponding signals in the multiplicity-edited 1H,13C-HSQC NMR spectrum. The two H6 signals of MurNAc were observed in opposite phase due to the multiplicity selection.
