Fig. 3.

KRM1-bound CV-A10 structures under neutral and acidic conditions. (A) Density maps of the mature CV-A10/KRM1 complex at pH 7.4 (3.0 Å; Left) and pH 5.5 (3.0 Å; Right) viewed along the icosahedral two-fold axes. (Insets) Close-up views of asymmetric units at the receptor-binding interface. (B) Close-up view of the hydrophobic pocket and the “pocket factor” inside, corresponding to pH 7.4 and pH 5.5, respectively. The density map is shown at 2.5σ contour. (C) Atomic models of an asymmetric unit of a CV-A10 virion with (dark colors) or without (light colors) KRM1 binding are aligned. The VP2 EF-loop, VP3 C terminus, and GH-loop are highlighted by dashed boxes, and their close-up views are shown at the side. KRM1 is not shown in the superimposition for clarity. (D) Comparison of each viral subunit in the CV-A10/KRM1 complex at pH 7.4 and pH 5.5. The structures at neutral (gray) and acidic (colored) pH conditions are shown as ribbons and overlaid for each subunit. The N and C termini of each protein are indicated by black dots.