Figure 1.
Substrate saturation plots of wild-type, Thr-226 → Ile, and Ile-225 → Thr-Thr-226 → Ile mutant chorismate mutase. The enzymes were assayed with 10 μM tryptophan (diamonds), without effectors (circles), or in the presence of 100 μM tyrosine (squares). The data were fitted to functions describing cooperative or Michaelis–Menten-type saturation.