The effects of an amino acid substitution in the D1 protein of photosystem II on its binding to different herbicides are here successfully predicted. This is done by assuming additivity in the contributions to the binding energy of the amino acids at positions 255 and 264 of this protein which are part of the herbicide binding niche. Additivity in D1 protein-herbicide interactions is demonstrated, thus indicating an apparent lack of interactions between the amino acids at these two positions.
