Figure 4.

Secondary alignment (or side-by-side representation) of wild protein (MiFRS) (gray-stick carbons) with the MiFRS^Phe473Trp mutant (green-stick carbons). The surface highlights the volume adopted by the friedelin molecule in the catalytic cavity. The green stick indicates the mutated residue. (a) Favorable interaction between the wild-type Phe473 residue and substrate. (b) Steric bulk of Trp473 residue at the active site of MiFRS^Phe473Trp. Interaction between Trp417 and Trp473 residues is favorable, which blocks the substrate entrance inside the pocket.