Fig. 3: In situ cryo-EM analysis of the structure of PEDV PT52 S on intact viruses.
From: In situ structure and dynamics of an alphacoronavirus spike protein by cryo-ET and cryo-EM
a Raw micrograph illustrating clear densities of S proteins on the viral membrane surface. 3701 micrographs were collected for this dataset (Supplementary Fig. 3). Orthogonal views of the cryo-EM maps of the D0-down conformation (D0DDD) (b) and the D0-up conformation (D0UDD) (c) with their respective atomic models are shown in cartoon representations in d and e. f Domain definitions of the PEDV PT52 S with the domain boundaries are indicated below. The individual domains are colored in the same scheme as in d and e. The regions that are missing in the cryo-EM structures are outlined by dashed lines. SS, signal sequence; D0, domain 0; NTD, N-terminal domain of S1; SD1, subdomain 1 of S1; CTD, C-terminal domain of S1; SD2, subdomain 2 of S1; FP, fusion peptide; HR1, heptad repeat 1; HR2, heptad repeat 2; TM, transmembrane domain; The black arrows highlight the protease cleavage sites S1/S2 and S2’. g Superimposition of the D0-down (purple) and D0-up (green) conformation S protomer models depicting the motion of the D0.
