Cryo-EM structure of the SARS coronavirus spike glycoprotein in complex with its host cell receptor ACE2
Fig 5
The pre- to post-fusion structural transition of the S2 subunit.
Left: ribbon diagrams showing the prefusion SARS-CoV S2 structure in which the “down” CTD1 has direct contacts with the helix linker 2 (blue). H1: helix 1. H2: helix 2. H3: helix 3. H1, H2 and helix linker 1: cyan. Helix linker 2: blue. H3: dark green. CTD1: red. Connecting domain: pink. Middle: ribbon diagrams showing the S2 region of the S-ACE2 complex in which the “up” CTD1 has no direct contacts with the Helix linker 2. Right: ribbon diagram of the postfusion SARS-CoV S2. H1, H2, H3 and the linkers transit to form the long central helix. HR2: yellow.