Sybodies clash with ACE2 in RBD complex structures.A, Sb16 (slate), Sb45 (cyan), Sb14 (blue), and Sb68 (purple)—RBD complexes were superposed on the ACE2–RBD structure (salmon) (6M0J) based on the RBD. Views of Sb16 (B), Sb45 (C), and Sb14 (D) are shown alone as well. Sb14 and Sb16 are buried inside ACE2, Sb45 is partially buried in ACE2, and Sb68 has major clashes with two N-glycan sites (N322 and N546) of ACE2 (inset). E, epitopic area (on the RBD) captured by ACE2 (salmon) is indicated along with its BSA. ACE2, angiotensin-converting enzyme 2; BSA, buried surface area; RBD, receptor-binding domain.