초록
<P>The oxygen-tolerant and molybdenum-dependent formate dehydrogenase FdsDABG from <I>Cupriavidus necator</I> is capable of catalyzing both formate oxidation to CO<SUB>2</SUB> and the reverse reaction (CO<SUB>2</SUB> reduction to formate) at neutral pH, which are both reactions of great importance to energy production and carbon capture. FdsDABG is replete with redox cofactors comprising seven Fe/S clusters, flavin mononucleotide, and a molybdenum ion coordinated by two pyranopterin dithiolene ligands. The redox potentials of these centers are described herein and assigned to specific cofactors using combinations of potential-dependent continuous wave and pulse EPR spectroscopy and UV/visible spectroelectrochemistry on both the FdsDABG holoenzyme and the FdsBG subcomplex. These data represent the first redox characterization of a complex metal dependent formate dehydrogenase and provide an understanding of the highly efficient catalytic formate oxidation and CO<SUB>2</SUB> reduction activity that are associated with the enzyme.</P><BR>[FIG OMISSION]</BR>