Fig. 4

Binding of methyl α-l-fucopyranoside to GII.4 Saga P-dimers. a, b Chemical shift perturbations (CSPs) of NH backbone signals of GII.4 Saga NN P-dimers (a) and iDiD P-dimers (b) in the presence of 160 and 220 mM methyl α-l-fucopyranoside, respectively. Dashed lines are at 2σ (red, blue) and at the experimentally determined significance threshold of 7.9 Hz (orange, light blue). c, d CSPs for NN (c) and iDiD P-dimers (d) mapped on the crystal structure (pdb: 4X06) of GII.4 Saga P-dimers. Color coding as in a and b. e Clusters of amino acids (N backbone atoms are shown as balls) of NN P-dimers reflecting two distinct types of binding isotherms (cf. Supplementary Note 2 and Supplementary Fig. 13). Color coding is as in h. f, g Global fitting of the law of mass action to chemical shift titration curves of NN P-dimers for amino acids belonging to the magenta cluster (f) and for iDiD P-dimers (g). For details of the curve fitting see Supplementary Note 2, Supplementary Equation 11, and Supplementary Table 8. The curves reflect one-site binding, and global fitting yields dissociation constants of K_D = 22 mM and of K_D = 220 mM for NN and iDiD P-dimers, respectively. h Complete linkage clustering separating amino acids of NN P-dimers based on distinct shapes of binding isotherms into two clusters (magenta and green). Source data are provided as a Source Data file