Figure S5.

Cryo-EM Analysis of Echo 6 Virus and Its Complex with Receptors, Related to Figure 4

(A) Gold-standard Fourier shell correlation (FSC) curves of the structures of Echo 6 virus alone or in complex with its receptors. The 0.143 cut-off value is shown to indicate the resolution of each reconstruction.

(B) Local resolution maps of representative density maps of Echo 6 virus or its complex with receptors. In all of these structures, most regions reach 3.0 Å and allowed the atomic details to be resolved.

(C-K) Representative density maps and atomic models of the pocket region or receptor binding interface. Most side chains of key residues within the pocket are clearly resolved. The “pocket factor” is preserved in structures of free Echo 6 full-particle or in complex with CD55 at both pH 7.4 and pH 5.5. In the structures with FcRn binding, it is well accommodated at pH 7.4, but is released at pH 5.5.