X-ray model of sybody superposed on cryo-EM structures of SB45–S-6P.A, model of Sb45+S-6P (1-up, 2-down) is fitted to the map with Sb45-X bound to RBD-A (up); Sb45-Y to RBD-B (down), and Sb45-Z to RBD-C (down). CCs (Sb45-X/Sb45-Y/Sb45-Z) are 0.52/0.49/0.57 respectively. B, model of Sb45+S-6P (2-up, 1-down) is fitted to the map with Sb45-X bound to RBD-A (up) and Sb45-Z bound to RBD-C (down), and CCs (Sb45-X/Sb45-Z) are 0.47/0.70, respectively. CCs, correlation coefficients; RBD, receptor-binding domain.