FIG 8.

Three-dimensional structural analyses of the S proteins of icPC22A and icPC22A-S1Δ197. The S1 subunit monomers of icPC22A (A) and icPC22A-S1Δ197 (B) and S protein trimers of icPC22A (C) and icPC22A-S1Δ197 (D) were modeled based on the cryo-EM structure of human coronavirus NL63 S protein from the Protein Data Bank (PDB accession number 5SZS) (60). The 197-amino-acid region, designated domain 0, is highlighted in orange, whereas other domains in the S1 subunit are highlighted in blue; the S2 subunit is in gray.