Abstract: | Highlights 1 Deletion of residues 156–157 warps the neighboring beta-sheet and leads NTD and RBD to shift. 2 T859N stabilizes the packing of the 630 loop motif to make RBD standing transition more difficult. 3 The overall structures of the closed state S complex from different variants resemble each other. 4 Mutations in FPPR may affect the overall structure of the trimeric spike protein. |