Cryo-EM structure of the SARS coronavirus spike glycoprotein in complex with its host cell receptor ACE2
Fig 6
A cartoon representation showing the pre- to post-fusion transition of the SARS-CoV S glycoprotein.
The “down” to “up” transition of the receptor-binding domain (CTD1) allows receptor binding. The binding to ACE2 opens up CTD1 and CTD2, promotes the disassociation of the S1-ACE2 complex from the S1/S2 cleaved S glycoprotein, induces the pre- to post-fusion transition of the S2 subunit, and initiates the membrane fusion.