Nitrogenase iron-protein structure

Georgiadis, M.M., Komiya, H., Chakrabarti, P., Woo, D., Komuc, J.J., Rees, D.C. (1992). Crystallographic structure of the nitrogenase iron protein from Azotobacter Vinelandii. Science 257, 1653-1659. 

Strop P,Tatahara PM, Chiu H-J, Angove HC. Crystal structure of the all-ferrous [4Fe-4S]° form of the nitrogenase iron protein from Azotobacter vinelandii. Biochemistry 2001 40 651-6. 

B. Nitrogenase Molybdenum-Iron Protein Structural Description of the Nitrogenase Proteins... 

C. Nitrogenase Molybdenum-Iron Protein Structure Structures of the Metal Centers of Nitrogenase... 

M.M. Georgiadis, H. Komiya, P. Chakrabarti, D. Woo, J.J. Komuc, and D.C. Rees. 1992. Crystallographic structure of the nitrogenase iron protein from Azotobacter vinelandii Science 257 1653-1659. (PubMed)... 

Garcia-Horsman JA, Berry E, Shapleigh JP, Alben JO, Gennis RB (1994) A novel cytochrome c oxidase from Rhodobacter sphaeroides that lacks Cua. Biochemistry 33 3113-3119 Georgiadis MM, Komiya H, Chakrabarti P, Woo D, Komuc JJ, Rees DC (1992) Crystallographic structure of nitrogenase iron protein from Azotobacter vinelandii. Science 257 1653-1659... 

For updating the information presented in this chapter, a literature search on the keyword nitrogenase modified with structure, X ray, Mossbauer, iron sulfur cluster, or model compound will generate citations referring to the newest research results. A search of the Protein Data Bank (PDB) at the website address http //www.rcsb.org/pdb/ will yield the latest updates on X ray, NMR, and other submitted structural data. 

Kim, J. and D.C. Rees. Structural models for the metal centers in the nitrogenase molybdenum-iron protein. Science 257,1677-1682 (1992). 

MgATP hydrolysis and, 47 189-191 nitrogenase complex, 47 186-189 substrates, 47 192-202 molybdenum iron proteins, 47 161, 166-174, 176-183, 191-192 structure, 47 162-164, 166-170 nitrogen fixation role, 36 78 in nitrogen fixation systems, 27 265-266 noncomplementary reactions with Sn", 10 215... 

The conversion of dinitrogen to ammonia is one of the important processes of chemistry. Whereas the technical ammonia synthesis requires high temperature and pressure (1), this reaction proceeds at room temperature and ambient pressure in nature, mediated by the enzyme nitrogenase (2). There is evidence that N2 is bound and reduced at the iron-molybdenum cofactor (FeMoco), a unique Fe/Mo/S cluster present in the MoFe protein of nitrogenase. Although detailed structural information on nitrogenase has been available for some time (3), the mechanism of N2 reduction by this enzyme is still unclear at the molecular level. Nevertheless, it is possible to bind and reduce dinitrogen at simple mono- and binuclear transition-metal systems which allow to obtain mechanistic information on elemental steps involved... 

Avaible experimental structural and kinetics data and energetic considerations indicate two plausible roles of ATP in the nitrogenase reduction a) the triggering of electron transfer from iron protein to iron-molybdenum protein (Howard and Rees, 1994 Rees and Howard, 2000) and the strengthening reducing power of the enzyme catalytic redox centers (Likhtenshtein and Shilov, 1977, Likhenshtein 1988a, Syrtsova and Timofeeva, 2001 see also Section 6.1.4). 

Bolen, J.T., Cambasso, N., Muchmore, S.W., Morgan, T.V., and Mortenson, L. E. (1993) Structure and Environment of metal clusters of the nitrogenase molybdenum iron protein from Clostridium pasterianum, in Stiefel, E.I., Coucouvanis, D., and ewton, W.E. (eds.), Molibdenum Enzymes, Cofactors, and Model Systems, Am. Chem. Soc., Wahington, DC. 

Kim, J. and Rees, D.C. (1992) Crystallographic structure and functional implication of the nitrogenase molybdenum-iron protein from Azotobacter vinelandii, Nature 360, 556-560. 

Vanadium nitrogenase is produced by certain bacteria grown in molybdenum-deficient environments. It is effective in the reduction of N2 and other nitrogenase substrates, although with less activity than the Mo—Nase. The enzyme resembles the Mo analogue (see Sections 17-E-10 and 18-C-13) in the construction and structure of the prosthetic groups, as well as in its functions.101 It consists of a FeV protein, FeVco, and an iron protein (a 4Fe—4S ferredoxin). 

The sequential electron transfer path in nitrogenase is followed first models of the Fe4S4 cluster of the iron-protein are discussed, then mimics of the P-cluster in the molybdenum-iron protein, and finally structural and functional models of the FeMo-cofactor are summarized. 

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