View source for 10zk


==CryoEM structure of Gluconacetobacter diazotrophicus nitrogenase complex (2:1 FeP:MoFeP) inhibited by BeFx (C2 symmetry)==
<StructureSection load='10zk' size='340' side='right'caption='[[10zk]], [[Resolution|resolution]] 2.73&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[10zk]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Gluconacetobacter_diazotrophicus_PA1_5 Gluconacetobacter diazotrophicus PA1 5]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=10ZK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=10ZK FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.73&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=0BE:BERYLLIUM'>0BE</scene>, <scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene>, <scene name='pdbligand=HCA:3-HYDROXY-3-CARBOXY-ADIPIC+ACID'>HCA</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=10zk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=10zk OCA], [https://pdbe.org/10zk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=10zk RCSB], [https://www.ebi.ac.uk/pdbsum/10zk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=10zk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NIFH_GLUDA NIFH_GLUDA] The key enzymatic reactions in nitrogen fixation are catalyzed by the nitrogenase complex, which has 2 components: the iron protein and the molybdenum-iron protein.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Nitrogenase is the only known enzyme that catalyzes the reduction of dinitrogen to ammonia. The most prevalent isozyme, molybdenum nitrogenase, comprises the catalytic molybdenum-iron protein (MoFeP) and the ATP-dependent reductase iron protein (FeP). Although Mo-nitrogenases are widespread across bacteria and archaea and appear to share conserved mechanistic and structural features, FeP and MoFeP show considerable sequence variability across diazotrophs. This raises questions about the conservation of chemomechanical mechanisms coupling FeP-dependent ATP hydrolysis and electron transfer to MoFeP, and about the functional compatibility of nitrogenase components from divergent species. Previous studies showed that some heterologous FeP-MoFeP pairs can functionally complement each other, whereas other pairs lack catalytic activity, but the absence of structural information on such heterologous pairs has limited mechanistic understanding. To this end, we investigated the functional and structural compatibility of FeP and MoFeP from Azotobacter vinelandii (Av) and Gluconacetobacter diazotrophicus (Gd), two phylogenetically and ecologically distinct species. Building on our prior work with Gd-nitrogenase and recently developed cryogenic electron microscopy (cryoEM) protocols, we determined the ADP.BeF(x)-trapped structure of the homologous GdFeP-GdMoFeP complex and showed that it adopted the same geometry as its Av counterpart. Activity measurements showed that heterologous Gd/Av combinations retained 60-80% of homologous catalytic activities despite 30-50% sequence divergence in FeP and MoFeP. High-resolution cryoEM structures of GdFeP-AvMoFeP and AvFeP-GdMoFeP corroborated these activities and revealed that functional complementation tolerates substantial sequence variation when the core structural elements supporting ATP binding/hydrolysis, protein-protein interaction, electron transfer, and substrate reduction are conserved.

Structural and Functional Characterization of Heterologous Nitrogenase Complexes.,Li Y, Narehood SM, Cook BD, McGuire KL, Herzik MA Jr, Tezcan FA Biochemistry. 2026 Jul 2. doi: 10.1021/acs.biochem.6c00360. PMID:42390130<ref>PMID:42390130</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 10zk" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Gluconacetobacter diazotrophicus PA1 5]]
[[Category: Large Structures]]
[[Category: Cook BD]]
[[Category: Herzik Jr MA]]
[[Category: Li Y]]
[[Category: McGuire KL]]
[[Category: Narehood SM]]
[[Category: Tezcan FA]]