Crystallization and preliminary X-ray analysis of a NADPH 2-ketopropyl-coenzyme M oxidoreductase/carboxylase

NADPH 2-ketopropyl-coenzyme M (2-mercaptoethanesulfonate) oxidoreductase/carboxylase is the terminal enzyme in a metabolic pathway that results in the conversion of propylene to the central metabolite acetoacetate. This enzyme is an FAD-containing enzyme that is a member of the NADPH:disulfide oxidoreductase family of enzymes and catalyzes the cleavage and carboxylation of 2-­ketopropyl-coenzyme M to form acetoacetate and coenzyme M. Crystallization trials have revealed that the highest diffraction quality crystals (better that 2.0 Å resolution) could be achieved when the substrate or product of the reaction was added to the enzyme in a stoichiometric excess.