The structure and dynamics of water molecule networks underlie catalytic efficiency in a glycoside exo-hydrolase

We investigate the role of the non-nucleophilic E220 glutamate, which is not involved directly in catalysis but essential in maintaining the water molecule network in a family 3 (GH3) β-d-glucan glucohydrolase. We generate the E220A mutant, measure its enzyme kinetics, elucidate crystal structures and deploy molecular dynamics simulations. Our findings provide a blueprint for the dynamics of catalysis mediated by hydrolytic enzymes, which could inspire bioengineering to create a sustainable bio-economy.