YEAST CHORISMATE MUTASE AND OTHER ALLOSTERIC ENZYMES

Analysis of five crystal structures of dimeric yeast chorismate mutase include a T-state bound to the allosteric inhibitor Tyr, two R-state mutants and two super-R wildtype structures bound to the transition st ate inhibitor plus either Tyr or the allosteric activator Trp. Relativ e rotations of one subunit relative to the other are 0 degrees (refere nce) for T, 15 degrees for R and 22 degrees for super-R states. A well defined pathway for conformational changes occurs from the active sit e to the subunit interface. Comparisons are made with other allosteric enzymes.