Stereo view of the vaniprevir complexes.

(A) Vaniprevir bound to the wild-type protease with the substrate envelope in blue. Intra- and inter-molecular hydrogen bond interactions are marked as red and grey dashed lines. Vaniprevir is shown bound to the drug-resistant variants (B) R155K, (C) D168A and (D) A156T with the transparent coordinates representing the wild-type structure to better highlight the molecular changes of each mutation. In all cases, catalytic residues are depicted in yellow, the P2 subsite in pink, and the drug molecules in orange.