   5.1.3.30 | sitting drop method. The crystal structure of the apoenzyme and the enzyme in complex with substrates or products (D-psicose, D-fructose, D-tagatose and D-sorbose). From the complex structures of the enzyme with D-psicose and D-fructose, the enzyme has much more interactions with D-psicose than D-fructose by forming more hydrogen bonds between the substrate and the active site residues. Accordingly, based on these ketohexosebound complex structures, a C3-O3 proton-exchange mechanism for the conversion between D-psicose and D-fructose is proposed. These results provide a clear idea for the deprotonation/protonation roles of E150 and E244 in catalysis |
728717 |
