SARS-CoV-2 spike protein 6VSB with one Receptor Binding Domain (RBD) up in the active conformation

SARS-CoV-2 spike protein from 6VSB. The protomer that has its Receptor Binding Domain (RBD) flipped into the up (active) conformation has its domains colored as described in Figure 1 of: Wrapp, D. , Wang, N. , Corbett, K.S. , Goldsmith, J.A. , Hsieh, C.L. , Abiona, O. , Graham, B.S. , McLellan, J.S. (2020) Science 367 : 1260-1263

Blue: N-Terminal Domain (NTD)

Green: Receptor Binding Domain (RBD)

Tan: Remainder of S1

Cyan: Fusion Peptide

Yellow: Heptad Repeat 1

Orange: Central Helix

Purple: Connector Domain

Red: Remainder of S2

See also 3dpx-012877 for a related structure from SARS-CoV with all RBD down in the inactive conformation.