Figure 5
ciA-C2 binds to both subdomains of HCA1 while CR1 primarily binds to HCNA1. (A) Superposition of the structures of the HCA1-ciA-C2 and HCA1-CR1 (PDB: 2NYY) complexes. (B) A close-up view of the interface around the HCCA1 subdomain highlighted in a box in panel A. ciA-C2 (cyan) occupies a crucial SV2-binding area on HCCA1 (orange) involving residues T1145 and T1146, but CR1 (red) does not. (C) Pull-down assays using gSV2C as bait and HCA1 (WT and mutants) as preys. TT/VV: HCA1-T1145V-T1146V. Ni-NTA resins incubated with HCA1-WT in the absence of gSV2C were used as a negative control.
