Structural and Catalytic Variations within the Three Families of Molybdenum Enzymes

Structural and Catalytic Variations Within the Three Families of Molybdenum Enzymes 

As for the reactions catalyzed by members of this third family of molybdenum enzymes, there are several variations from the principal theme of oxygen atom transfer. Formate dehydrogenase from E. coli catalyzes the oxidation of formate to CO2, a reaction that isotope studies have shown does not pass through a bicarbonate intermediate (Khangulov et al., 1998). Instead, it appears likely that C02is formed by direct hydride transfer from substrate to the molybdenum center. Polysulfide reductase is another molybdenum enzyme that catalyzes a non-canonical reaction the 

With this background information, the three families of molybdenum enzymes will be considered in turn, focusing in each case first on structural aspects followed by a discussion of reaction mechanism. 

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