Fig. 8

Cryo-EM structures of Tr67 in complex with the SARS-CoV-2 (Omicron BA.1) spike protein. a EM density map of Tr67-spike complex in “3-RBD-up” conformation at the overall resolution of 9 Å. b Fitting of the atomic model of the designed Tr67-spike complex into the EM density map. The EM density is shown as a transparent gray surface and the spike protein is rendered in blue. c Cross-section view of the stem region of the spike protein. d An open-like, “3-RBD-up” conformation with the SARS-CoV-2 (Wuhan-Hu-1) spike protein induced by three separated Nb67. e The binding interfaces of trivalent (left panel) and monovalent (right panel) Nb67 binding with the RBDs (shown as gray surface) are shown in pink, and the contact residues on Nb67 are shown as sticks