a. Distributions of favourable regions around the 6 Tyr residues in the vicinity of the thermolysin binding pocket for aromatic NH atoms. The purple contours define the favourable regions, while the red contours show the highly favoured ones.
Similar distributions can be generated for all the other sidechains in the vicinity.
b. Resultant contours obtained from overlapping the contributions of all nearby sidechains. Here only contours falling within the `mask' region - ie that defining the binding pocket - are considered.