Fig. 2

Structure and domain organization of the Spike protein of the SARS-CoV-2. a The S1 subunit includes the RBD, which is responsible for the interaction with the ACE2 receptor on the host cell membrane. The subunit S2 includes the membrane fusion complex (fusion peptide, heptad repeats HR 1 and HR2), anchors the S2 subunits to the viral membrane with its transmembrane domain, and interacts with the viral ribonucleoprotein complex through its endodomain. b D614G mutation in the Spike protein and frequency across the time