Skip to main content
. Author manuscript; available in PMC: 2016 Dec 13.
Published in final edited form as: Nat Struct Mol Biol. 2016 Jun 13;23(7):656–662. doi: 10.1038/nsmb.3245

Figure 4.

Figure 4

The SV2 glycan binding mode is conserved in BoNT/HA. (a) The SV2C glycan plays an indispensable role for HCHA binding as demonstrated by a pull-down assay using human bSV2C (with a SUMO tag) or gSV2C as baits. “Mu” is HCHA-F943G mutant. (b) The F943G mutation dramatically decreased HCHA binding to rat cortical neurons as analyzed by immunostaining and immunoblot. The uncropped images of the gels and blots are shown in Supplementary Data Set 1. (c) Proposed model for simultaneous binding of BoNT/A1 to two neuronal surface receptors: glycosylated SV2 and ganglioside. GT1b is modeled based on the structure of a GT1b-bound HCA (PDB code 2VU9) 37. A representative complex type N-linked glycan is modeled based on the structure of a glycan of human IgG1 (PDB code 3AVE) 38. The glycan core that is observed in the HCA–gSV2C complex is colored green, whereas the remaining carbohydrates (mannose and NAG colored gray) could potentially extend to the N-terminal sub-domain of HCA (HCNA).