Figure 3.
Cryo-EM structures of Omicron S trimer in complex with bispecific single-domain antibody bn03
(A) Bispecific single-domain antibody bn03 binds to Omicron S trimers in 3 states. Two perpendicular views of Omicron S-bn03 are depicted as surface, with n3113v in magenta, n3130v in blue, and the trimeric spike in cyan, pink, and yellow.
(B) Superposition of RBD-bound n3113v on B-RBD of state 1 structure indicates a clash. A-RBD-bound n3113v is shown as magenta surface. The docked n3113v is shown in red surface.
(C) Alignment of down-state spike from molecule C (pink) and molecule B (yellow) of state 1 structure. The down-state spike is shown as cartoon. Protomer A and C in Omicron S-bn03 structure are depicted as gray surface.
(D) Quaternary binding of n3130 and RBDs. Top view of the state 1 structure shown in cartoon representation.
(E) Comparison of the up-RBDs of bn03-bound Omicron S complexes with the up-RBD of Omicron S-apo (gray). The n3113v-bound state-2 C-RBD is colored orange. The n3113v-n3130v-bound state-1-C, state 2&3-B, and state 3-C are colored green, blue, and magenta, respectively.
See also Figure S5.