Electron microscopy of the hydrogenase from the hydrogen-oxidizing bacterium Alcaligenes eutrophus Z1

The quaternary structure of the NAD-dependent hydrogenase from the hydrogen-oxidizing bacterium Alcaligenes eutrophus Z1 has been studied by electron microscopy. A model of the hydrogenase molecule with two small subunits arranged between two large ones in linear fashion is proposed. The electron microscopy studies are in accordance with the previously proposed linear electron transport chain of the hydrogenase and distribution of the substrate binding sites within the enzyme molecule.