Figure 9.

Structural insights into the SARS-CoV-2 S protein–ACE2 interaction. (A) Cryo-EM structure of the SARS-CoV-2 RBD–ACE2–B⁰AT1 protein complex reported by Yan et al. (6M17). The complex is shown as a colorized ribbon model and molecular surface with the RBD, ACE2, and B⁰AT1 shown in red, blue, and green, respectively. (B) Superposition of ACE2-complexed SARS-CoV (2AJF, brown) and SARS-CoV-2 (6M0J, purple) RBDs aligned by the RBD (refs (70 and 93)). The ACE2 structure for the SARS-CoV-2 complex is shown alone to simplify the RBD–ACE2 interface. The major structural discrepancy between the SARS-CoV and SARS-CoV-2 RBDs is circled with a black dotted line. The side chains of residues mutated in variants of concern (prior to the Omicron variant) are shown and labeled in red. (C) The same as in panel B, but mutated residues are shown for the Omicron BA.2 variant.