Fig. 8.
Comparison of the potential substrate-binding motifs of the PEDV and SARS-CoV 3CLpros. A. A cartoon view of the four motifs around the substrate. The PEDV 3CLpro complex structure (magenta) is superimposed with the complex structure of the SARS-CoV 3CLpro variant (C144A) (PDB identifier 2Q6G) (green). The peptide substrate is colored blue. The four motifs and some residues shown as stick diagrams are labeled. B. Sequence alignment of the four motifs of 3CLpros of the three coronavirus groups. The residues that are relatively conserved in Alphacoronavirus 3CLpro but differ from those of Betacoronavirus 3CLpro are marked with pink vertical lines. C. Electrostatic surface potential of the PEDV 3CLpro complex structure. The four motifs are shown as a magenta cartoon and the substrate is shown as blue sticks. Three residues shown as stick diagrams are labeled. D. Electrostatic surface potential of the SARS-CoV 3CLpro complex structure. The four motifs are shown as a green cartoon and the substrate is shown as blue sticks. Three residues shown as stick diagrams are labeled, and the negatively charged area (red) of motif4 is labeled.