Supplementary Figure 1: The structure of the HCA–SV2C complex.
From: N-linked glycosylation of SV2 is required for binding and uptake of botulinum neurotoxin A
(a) The structure of human gSV2C displays a unique pentapeptide-repeat motif, where phenylalanine residues spaced 5 residues apart (except S527) provide important stacking effect to stabilize the structure. These residues are shown in sticks, with the ones that are conserved in all three SV2 isoforms across different species are colored gold. (b) The structures of HCA in complex with the rat bSV2C or human gSV2C are superimposed. The N559 glycan of gSV2C is shown as a transparent sphere model. Residue F563 of human SV2C is replaced by L563 in rat SV2C, which abolishes the cation-π stacking interaction. (c) The protein–protein interface between HCA and the human gSV2C. The plots were generated using LIGPLOT (Laskowski, R.A. et al., J Chem Inf Model 51, 2778-86 2011). BoNT/A and SV2C residues are labeled brown and green, respectively. Hydrogen bonds are indicated by dashed green lines. A similar interaction network is observed in the structure of HCA in complex with the rat bSV2C, except that the cation-π stacking interaction (double arrow) is unique for human SV2C.
