COVID-19 pandemic: Insights into structure, function, and hACE2 receptor recognition by SARS-CoV-2
Fig 5
Structure of the SARS-CoV-2 S protein alone and in complex with ACE2 receptor.
(A) Side view of the trimeric SARS-CoV-2 S ectodomain in the prefusion state (PDB: 6VSB). The protomer in green is in the “up” conformation, and the other 2 protomers in red and cyan are in “down” conformation. (B) Top view of the trimeric S protein showing RBDs in red, blue, and green on each protomer. (C) Structure of a single protomer showing the receptor-binding subunit S1 (blue) and the membrane-fusion subunit S2 (green). The furin-like protease site at the boundary of S1/S2 subunits is depicted. (D) The S1 subunit showing the RBM in the CTD region (blue) and the NTD region (brown). The S2 subunit showing the fusion peptide (red), second cleavage site S2′ (black), and HR1 (pink). (E) Structure of the RBD, core subdomain (green), and RBM (blue) (PDB: 6LZG). (F) SARS-CoV-2-RBD:ACE2 receptor polar interface shown by specific residues. (G) Structure of the SARS-CoV-2-RBD in complex with ACE2 receptor (PDB: 6LZG). (H) Structural similarity between the SARS-CoV-RBD:hACE2 (green) and SARS-CoV-2-S-CTD:hACE2 (yellow) complexes. (I) Crystal structure of the SARS-CoV-2-RBD (green) in complex with a monoclonal antibody CR3022 (orange). The RBM and CR3022 binding sites do not overlap and are distantly located on the RBD (PDB: 6W41). The figures were prepared using Pymol. ACE2, angiotensin-converting enzyme 2; CTD, C-terminal domain; hACE2, human ACE2; HR1, heptad repeat 1; NTD, N-terminal domain; PDB, Protein Data Bank; RBD, receptor-binding domain; RBM, receptor-binding motif; S protein, spike protein; SARS-CoV, Severe Acute Respiratory Syndrome Coronavirus; SARS-CoV-2, Severe Acute Respiratory Syndrome Coronavirus-2.