View source for 4tku


==Reactivated Nitrogenase MoFe-protein from A. vinelandii==
<StructureSection load='4tku' size='340' side='right'caption='[[4tku]], [[Resolution|resolution]] 1.43&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4tku]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Azotobacter_vinelandii Azotobacter vinelandii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4TKU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4TKU FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.43&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=FE2:FE+(II)+ION'>FE2</scene>, <scene name='pdbligand=HCA:3-HYDROXY-3-CARBOXY-ADIPIC+ACID'>HCA</scene>, <scene name='pdbligand=IMD:IMIDAZOLE'>IMD</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4tku FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4tku OCA], [https://pdbe.org/4tku PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4tku RCSB], [https://www.ebi.ac.uk/pdbsum/4tku PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4tku ProSAT]</span></td></tr>
</table>
== Function ==
[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.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The mechanism of nitrogenase remains enigmatic, with a major unresolved issue concerning how inhibitors and substrates bind to the active site. We report a crystal structure of carbon monoxide (CO)-inhibited nitrogenase molybdenum-iron (MoFe)-protein at 1.50 angstrom resolution, which reveals a CO molecule bridging Fe2 and Fe6 of the FeMo-cofactor. The mu2 binding geometry is achieved by replacing a belt-sulfur atom (S2B) and highlights the generation of a reactive iron species uncovered by the displacement of sulfur. The CO inhibition is fully reversible as established by regain of enzyme activity and reappearance of S2B in the 1.43 angstrom resolution structure of the reactivated enzyme. The substantial and reversible reorganization of the FeMo-cofactor accompanying CO binding was unanticipated and provides insights into a catalytically competent state of nitrogenase.

Ligand binding to the FeMo-cofactor: structures of CO-bound and reactivated nitrogenase.,Spatzal T, Perez KA, Einsle O, Howard JB, Rees DC Science. 2014 Sep 26;345(6204):1620-3. doi: 10.1126/science.1256679. PMID:25258081<ref>PMID:25258081</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4tku" style="background-color:#fffaf0;"></div>

==See Also==
*[[Nitrogenase 3D structures|Nitrogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Azotobacter vinelandii]]
[[Category: Large Structures]]
[[Category: Einsle O]]
[[Category: Howard JB]]
[[Category: Perez K]]
[[Category: Rees DC]]
[[Category: Spatzal T]]