is not near the 4 catalytic amino acids of the opposite AHAS in the dimer in 6U9H using the 1YHZ CS coordinates; the distance from P197 to W574 is more than 15 A (nitrogen to nitrogen) in Figure . The 5K6Q x-ray structure of AHAS without CS is visually identical to the protein 1YHZ, which suggests a small dimer change to the corresponding one in structure 6U9H, if the illustrations (not x-ray structure) of the dimer interface with CS, is that small. In the complete structure 6U9H, and in the vicinity of the interface, there are no hydrogen bond contacts between the 2 monomers in the dimer cavity region or at the point of entry.