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</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CFM:FE-MO-S+CLUSTER'>CFM</scene>, <scene name='pdbligand=CLF:FE(8)-S(7)+CLUSTER'>CLF</scene>, <scene name='pdbligand=HCA:3-HYDROXY-3-CARBOXY-ADIPIC+ACID'>HCA</scene></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Nitrogenase Nitrogenase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.18.6.1 1.18.6.1] </span></td></tr>

[[https://www.uniprot.org/uniprot/NIFD_AZOVI NIFD_AZOVI]] This molybdenum-iron protein is part of the nitrogenase complex that catalyzes the key enzymatic reactions in nitrogen fixation. [[https://www.uniprot.org/uniprot/NIFK_AZOVI NIFK_AZOVI]] This molybdenum-iron protein is part of the nitrogenase complex that catalyzes the key enzymatic reactions in nitrogen fixation.

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== Publication Abstract from PubMed ==

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.

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<ref>PMID:9063865</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Day, M W]]

[[Category: Kim, J]]

[[Category: Peters, J W]]

[[Category: Rees, D C]]

[[Category: Soltis, S M]]

[[Category: Stowell, M H.B]]

[[Category: Oxidoreductase]]