a, Domain architecture of EBOV GP full length and the construct crystallized here, which is the ectodomain of an enzymatically cleaved GP (GPCL) resembling the form of GP generated in endosomes during viral entry lacking the glycan cap. HR1 and HR2, heptad repeat 1 and heptad repeat 2, respectively. Glycosylation sites are represented above the domains. b, Crystal structure of the trimeric EBOV GPCL–ADI-15946 complex. The inset table shows the contribution of each complementarity-determining region (CDR) to the buried surface area (BSA) on the surface of GPCL. c, The interaction bridges the fusion loop and other portions of GP2 primarily via light chain and CDR H3 contacts. CDRs H1 and H2 are not involved. d, The footprint of ADI-15946 (orange) is shifted up and to the left compared to that of the base-binding mAb, KZ52 (pink).