Fig. 1.

Structural overview of the SARS-CoV-2 spike (S) protein. a Schematic diagram of the SARS-CoV-2 virion and its S protein. E envelope, M membrane, N nucleocapsid, ACE2 angiotensin-converting enzyme 2. b Cryo-EM structure of the SARS-CoV-2 S protein trimer (PDB 6VXX). The three subunits are colored orange, green, and blue. c Close-up views of the SARS-CoV-2 S receptor-binding domain (RBD) and N-terminal domain (NTD) in the S1 subunit. d Crystal structure of the SARS-CoV-2 RBD in complex with human ACE2 (PDB 6M0J). Human ACE2 is colored in light blue