Fig. 5
a Cartoon representation of superimposed structures from SARS-CoV 3CLPro (PDB ID: 3TNT, grey) and SARS-CoV-2 3CLpro (PDB ID: 6Y2G, cyan) showing 94.44% sequence identity. Two different 3CLpro inhibitors represented in red and green colour in the substrate binding region (a’) magnified view of substrate binding region. b The residues of the catalytic dyad (His41 and Cys145) are shown in surface view. Autodock 4.2 docking protocol was validated by re-docking of O6K inhibitor in SARS-CoV-2 3CLpro, original O6K inhibitor is shown in red colour and re-docked pose in cyan colour c three-dimensional and d surface view representation