Fig 6. Co-crystal structure of S. Typhi PltB homopentamer bound to 4-O-acetylated α2–3 sialosides.

A, Crystal structure of PltB homopentamer in complex with Neu4,5Ac₂α2-3Galβ1-4GlcNAc is shown as a ribbon cartoon with each protomer depicted in a different color. Cyan sticks, sugar carbon atoms. Blue sticks, nitrogen atoms. Red sticks, oxygen atoms. BS1-3, binding sites 1–3. B, Surface charge distribution of the PltB pentamer structure and the indicated glycan. C-D, Close-up view of the interface between the BS1 (C)/ BS2 (D) and the indicated glycans with their electron density maps. Green sticks, sugar carbon atoms of the 4-O-acetyl group. E-F, Close-up views of the BS1 (E)/ BS2 (F) complexed with Neu4,5Ac₂α2-3Galβ1-4GlcNAc. Dotted lines, H-bonds. Gray balls, water.