Abstract
In 1946, Pauling stated the principle that enzymes function by preferentially binding the activated form of the substrate in the transition state. However, the high catalytic efficiency of enzymes is linked to their intrinsic flexibility, and recently it has been proposed that enzymes function primarily by minimizing the energy barrier to protein reorganization.
X-ray crystallography has made it possible, on the one hand, to identify the residues involved in the various chemical steps of enzyme catalysis and to observe certain catalytic intermediates. But it has also revealed the role of protein movement in enzyme catalysis. In this talk, I'll show you how obtaining several structures of the same enzyme in complex with its substrates, different reaction intermediates or products has enabled us to elucidate the different chemical steps, observe changes in the protein's conformation and, in some cases, reconstruct the complete film of the enzyme's catalytic action.
