Fig. 6. Chemical structures of covalent inhibitors and their crystal structures with the NS3/4A protease complex (a) telaprevir binding to Ser-1139 (PDB ID 3SV6), (b) narlaprevir (PDB ID ; 3LON), and (c) boceprevir (PDB ID ; 3LOX) binding to Ser-139. Inhibitors are shown as cyan sticks and Ser-1139, Ser-139 are shown as yellow sticks.
