Iron-oxo clusters

Zeth, K., Offermann, S., Essen, L.-O., and Oesterhelt, D. 2004. Iron-oxo clusters biomineralizing on protein surfaces structural analysis of Halobacterium salinarum DpsA in its low- and high-iron states. Proceedings of the National Academy of Sciences of the USA 101 13780-13785. 

Strongly supporting this spectroscopic data, Mossbauer spectroscopy of the as-isolated Rr shows the presence of two types of iron centers a magnetic component that can be well simulated by the parameters of Rd, and a diamagnetic component attributed to the diiron-oxo cluster and resulting from the antiferromagnetic coupling of the two irons. 

Resonance Raman Spectroscopy of Iron—Oxo and Iron—Sulfur Clusters in Proteins... 

It seems probable that other redox centres contain this binuclear iron structure, but that this has not yet been recognized. For example, a non-heme iron protein of the methane monooxygenase from Methylococcus capsulatus (Bath), which functions as the oxygenase in equation (28), has been described as having a novel iron centre which is not an iron-sulfur cluster. This may well be an oxo-bridged system. Analysis suggests 2.3 Fe per molecule of protein. 

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