FIGURE 2.

Identified compounds bind near the S1 (yellow) and S2 site (pink) of PLpro. Crystal structure of SARS-CoV-2 PLpro in complex with the identified hydrazone H1 and thiosemicarbazone binders T1-T5 overlayed with the binding ubiquitin [(A), green, PDB: 6xaa] and ISG15 molecules [(B), purple, PDB: 7rbs]. Five of the six identified ligands (T1–T5) are in a deep pocket near the S2 site, while the hydrazone H1 (magenta) is located at the end of the S1 site.