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3min
From Proteopedia
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'''NITROGENASE MOFE PROTEIN FROM AZOTOBACTER VINELANDII, OXIDIZED STATE''' | '''NITROGENASE MOFE PROTEIN FROM AZOTOBACTER VINELANDII, OXIDIZED STATE''' | ||
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[[Category: Soltis, S M.]] | [[Category: Soltis, S M.]] | ||
[[Category: Stowell, M H.B.]] | [[Category: Stowell, M H.B.]] | ||
| - | [[Category: | + | [[Category: Biological nitrogen fixation]] |
| - | [[Category: | + | [[Category: Molybdoenzyme]] |
| - | [[Category: | + | [[Category: Nitrogen fixation]] |
| - | [[Category: | + | [[Category: Nitrogen metabolism]] |
| - | [[Category: | + | [[Category: Oxidoreductase]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May 4 22:07:19 2008'' | |
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 19:07, 4 May 2008
NITROGENASE MOFE PROTEIN FROM AZOTOBACTER VINELANDII, OXIDIZED STATE
Overview
The structure of the nitrogenase MoFe-protein from Azotobacter vinelandii has been refined to 2.0 A resolution in two oxidation states. EPR studies on the crystals indicate that the structures correspond to the spectroscopically assigned oxidized (P(OX)/M(OX)) and the native or dithionite-reduced (P(N)/M(N)) forms of the enzyme. Both MoFe-protein structures are essentially identical, with the exception of the P-cluster. The MoFe-protein P-cluster in each state is found to contain eight Fe and seven S atoms. Interconversion between the two redox states involves movement of two Fe atoms and an exchange of protein coordination for ligands supplied by a central S atom. In the oxidized P(OX) state, the cluster is coordinated by the protein through six cysteine ligands, Ser-beta188 O gamma, and the backbone amide of Cys-alpha88. In the native P(N) state, Ser-beta188 O gamma and the amide N of Cys-alpha88 no longer coordinate the cluster due to movement of their coordinated Fe atoms toward the central sulfur. Consequently, this central sulfur adopts a distorted octahedral environment with six surrounding Fe atoms. A previously described model of the P-cluster containing 8Fe-8S likely reflects the inappropriate modeling of a single structure to a mixture of these two P-cluster redox states. These observed redox-mediated structural changes of the P-cluster suggest a role for this cluster in coupling electron transfer and proton transfer in nitrogenase.
About this Structure
3MIN is a Protein complex structure of sequences from Azotobacter vinelandii. Full crystallographic information is available from OCA.
Reference
Redox-dependent structural changes in the nitrogenase P-cluster., Peters JW, Stowell MH, Soltis SM, Finnegan MG, Johnson MK, Rees DC, Biochemistry. 1997 Feb 11;36(6):1181-7. PMID:9063865 Page seeded by OCA on Sun May 4 22:07:19 2008
