Use the molecular model (below) to obtain the measurements needed. The thin red lines link the atoms of interest.

1. Measure the distance between the sulphur atom of the

   thiophene ring and the closest carbon atoms of both leucine

   198 and valine 121.

2. Measure the distance between the closest sulfone oxygen

   atom (i.e. 7,7-dioxo) and the closest carbon atom of

   phenylalanine 131.

Atom colours:
Carbon - grey (ligand = green); Oxygen - red; Nitrogen - blue; Sulfur - yellow; Hydrogen - white