The Mo-Se active site of nicotinate dehydrogenase

The Mo-Se active site of nicotinate dehydrogenase.

Nicotinate dehydrogenase (NDH) from Eubacterium barkeri is a molybdoenzyme catalyzing the hydroxylation of nicotinate to 6-hydroxynicotinate. Reactivity of NDH critically depends on the presence of labile (nonselenocysteine) selenium with an as-yet-unidentified form and function. We have determined the crystal structure of NDH and analyzed its active site by multiple wavelengths anomalous dispe...

Oxidation-State-Dependent Binding Properties of the Active Site in a Mo-Containing Formate Dehydrogenase

Molybdenum-containing formate dehydrogenase H from Escherichia coli (EcFDH-H) is a powerful model system for studies of the reversible reduction of CO2 to formate. However, the mechanism of FDH catalysis is currently under debate, and whether the primary Mo coordination sphere remains saturated or one of the ligands dissociates to allow direct substrate binding during turnover is disputed. Here...

Probing the active site of liver alcohol dehydrogenase.

site for GSH has been assumed, there is no compelling evidence for the existence of ceoperativity between the subunits of the enzyme. The examples presented show that rate behaviour with regulatory properties can be realized without any assumptions of co-operative subunit interactions. Whether COoperativity indeed is operative in these enzymes remains to be established by the study of ligand bi...

Fast enzyme dynamics at the active site of formate dehydrogenase.

The role of femtosecond-picosecond structural dynamics of proteins in enzyme-catalyzed reactions is a hotly debated topic. We report infrared photon echo measurement of the formate dehydrogenase-NAD+-azide ternary complex. In contrast to earlier studies of protein dynamics, the data show complete spectral diffusion on the femtosecond-picosecond time scale with no static heterogeneity. This resu...

PROBING THE ACTIVE SITE OF RHODANESE WITH DISULFIDE REAGENTS