The crystal structures of the HBGA-binding interfaces of VA387 (GII.4) and VA207 (GII.9).

(A and B) The surface models of the P dimers (top views) of VA387 (A) and VA207 (B). One protomer is shown in light cyan, while the other in grey. The HBGA-binding interfaces are shown in darker colors. (C and D) Enlargements of the HBGA-binding interfaces with labels of individual amino acids. The prime symbol indicates a residue of the other protomer. The three major components of the binding pocket are colored in blue (bottom), orange (wall), and yellow/sand (another wall), respectively, while the nearby site that affects specificity of the binding interface is shown in purple. The type B trisaccharide binding to VA387 (A and C) is shown in cyan (C), red (O), and blue (N), while the Ley tetrasaccharide binding to VA207 (B and D) is shown in green (C), red (O), and blue (N).