Sandbox Reserved 1846: Difference between revisions

The original side chain at position 243 is phenylalanine, which is located 3.6 Å from the ligand. Two mutations at this position—F243I (isoleucine) and F243W (tryptophan)—increase the catalytic activity of the enzyme. The F243I mutation replaces phenylalanine with isoleucine, a smaller side chain that allows the ligand to sit closer. This reduces the ligand distance to 3.0 Å. This tighter interaction likely improves substrate binding. The F243W mutation introduces tryptophan, which has a bulkier, nitrogen-containing aromatic side chain. Tryptophan brings the ligand slightly closer at 3.2 Å and introduces potential for new interactions, such as hydrogen bonding or π-stacking. Both mutations result in improved catalytic performance. The F243I mutation leads to a 27.5% increase in activity, while the F243W mutation results in a 17.5% increase, compared to the wild-type enzyme.