Double cubane framework

The P-cluster is an intermediary electron transfer eenter of a structure type found only in nitrogenase. The P-cluster can exist in several oxidation states, of which only the normal, all-ferrous P state and the doubly oxidized P° (also known as P ) form have been structurally characterized. In the P state, the P-cluster core ean be viewed as two Fe4S4 cubanes bridged at a shared pg Sulfide vertex the resulting octanuclear FegS7 framework can thus be described as a vertex-fused double cubane (VFDC) structure. Two... 

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