Chemical Modification of the Active Center of Nitrogenase

The MoFe-protein of nitrogenase consists of two atom clusters (Kurtz et al. 1979, Mortenson et al. 1979). The first is the atom cluster of Fe4S4, four of which are contained in each MoFe-protein (Mw 22 kDa). The second is FeMo—co (Shah et al. 1978), two of which are contained in each MoFe-protein; it consists of one Mo, seven to eight Fe and six S2— (or four S2—). The first cluster has the function of electron transfer and the second serves as a chelating and reducing center for the substrate (Shah et al. 1978).