Rabies infection is nearly 100% lethal if untreated and kills over 50,000 people annually, many of them children. Existing rabies vaccines target the rabies virus glycoprotein (RABV-G) but generate short-lived immune responses, likely because the protein is heterogeneous under physiological conditions. Here, we report the 3.39Å cryo-EM structure of trimeric, pre-fusion RABV-G complexed with RVA122, a potently neutralizing human antibody. RVA122 binds to a quaternary epitope at the top of RABV-G, bridging domains and stabilizing RABV-G protomers in a prefusion state. RABV-G trimerization involves side-to-side interactions between the central α-helix and adjacent loops, rather than contacts between central helices, and interactions among the fusion loops at the glycoprotein base. These results provide a basis to develop improved rabies vaccines based on RABV-G stabilized in the prefusion conformation.
This is a companion discussion topic for the original entry at https://doi.org/10.1101/2021.11.16.468852