Biochemistry MoFe proteins

Pierik, A.J., Wassink, H., Haaker, H., and Hagen, W.R. 1993. Redox properties and EPR spectroscopy of the P clusters of Azotobacter vinelandii MoFe protein. European Journal of Biochemistry 212 51-61. 

Chiu, H-J, Peters, J. W., Lanzillota, W N., Ryle, M. J., Seefeldt, L. C., Howard, J.B., and Rees, D. C. (2001) MgATP-bound and nucleotide-free structure of a nitrogenase protein complex between the 127 D-Fe-protein and the MoFe-protein, Biochemistry 40, 641-650. 

DeRose, V.J. C.-H., Kim, W.E., Newton, D. R.D., and Hoffman B. M. (1995) Electron Spin Echo Modulation Spectroscopic Analysis of Altered Nitrogenase MoFe Proteins of Azotobacter vinelandii, Biochemistry 34, 2809-2814... 

The focus of this review will be primarily on the structures of the metal centers and polypeptide chains of the nitrogenase proteins, based on crystallographic structures of both the Fe-protein and the MoFe-protein, which have been recently determined at Caltech (15-19). Structural work on the MoFe-protein is also underway in the laboratory of J. Bolin at Purdue (19a). To minimize overlap with the existing, excellent reviews on the chemistry, biochemistry, biophysics, and genetics of nitrogenase and related chemical systems (2-8), these topics will be primarily discussed in the context of the nitrogenase protein structures. 

Progress in the biochemistry and spectroscopy of iron-only nitrogenase has occurred, with the most active, pure preparations reported in 1997. Mossbauer and EXAFS results support electronic and structural analogy between the eight-iron cluster in this enzyme (the FeFeco ) and the FeMoco. One notable difference is that the FeFeco is diamagnetic in its dithionite-reduced form, and thus corresponds to M° in the MoFe protein. Therefore, the oxidation states are thought to be Fe(II)4Fe(III)4 or Fe(II)6Fe(III)2, in analogy to the two most likely oxidation... 

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