Structure and Function of Nitrogenase

Structure and Function of Nitrogenase Douglas C. Rees, Michael K. Chan, and Jongsun Kim... 

To successfully describe the structure and function of nitrogenase, it is important to understand the behavior of the metal-sulfur clusters that are a vital part of this complex enzyme. Metal-sulfur clusters are many, varied, and usually involved in redox processes carried out by the protein in which they constitute prosthetic centers. They may be characterized by the number of iron ions in the prosthetic center that is, rubredoxin (Rd) contains one Fe ion, ferredoxins (Fd) contain two or four Fe ions, and aconitase contains three Fe ions.7 In reference 18, Lippard and Berg present a more detailed description of iron-sulfur clusters only the [Fe4S4] cluster typical of that found in nitrogenase s Fe-protein is discussed in some detail here. The P-cluster and M center of MoFe-protein, which are more complex metal-sulfur complexes, are discussed in Sections 6.5.2. and 6.5.3. 

Regarding the structure and function of nitrogenases in producing ammonia from N2, Sellmann has studied several model systems wherein heterolytic activation of H2 occurs on sulfur ligands (87). A core geometry based on a hybrid of the FeMoco active site structure with a dinuclear diazene complex, [Fe( NHS4 )]2(p-N2H2), is a proposed model (Scheme 4). 

Efforts to mimic the enigmatic structure and function of nitrogenases have been in progress for over 40 years in regard to producing anunonia or other nitrogen compounds from An important feature of nitrogenase is that it... 

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