Large numbers of docking runs in a thorough study show that the major conformational mode of binding of CS to Soybean AHAS is eliminated upon altering P197S. The amino acid Proline is very different from Serine in that there is no amine or side-chain. The binding site changes slightly, together with the solvent accessible surface, and this alters quite much the binding modes of the ligand and the epitopes in shape. The point mutation also has an effect of delocalizing the attachment of bound CS to its herbicide siteit generally loses a specific target location and binds more diffusely to a larger surface area containing the sub-region that CS binds to in P197. Both the loss of most of the major binding mode and the delocalization block the CS molecule from binding highly and specifically in location. This mutation weakens the blockage of the entry to the transport channel to the catalytic site and thus the plant becomes resistant.