View source for 6myu


==Avian mitochondrial complex II crystallized in the presence of HQNO==
<StructureSection load='6myu' size='340' side='right'caption='[[6myu]], [[Resolution|resolution]] 1.97&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6myu]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Gallus_gallus Gallus gallus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6MYU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6MYU 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]] 1.97&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=3PE:1,2-DIACYL-SN-GLYCERO-3-PHOSPHOETHANOLAMINE'>3PE</scene>, <scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=FES:FE2/S2+(INORGANIC)+CLUSTER'>FES</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=MLZ:N-METHYL-LYSINE'>MLZ</scene>, <scene name='pdbligand=OAA:OXALOACETATE+ION'>OAA</scene>, <scene name='pdbligand=PEG:DI(HYDROXYETHYL)ETHER'>PEG</scene>, <scene name='pdbligand=UMQ:UNDECYL-MALTOSIDE'>UMQ</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=6myu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6myu OCA], [https://pdbe.org/6myu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6myu RCSB], [https://www.ebi.ac.uk/pdbsum/6myu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6myu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SDHA_CHICK SDHA_CHICK] Flavoprotein (FP) subunit of succinate dehydrogenase (SDH) that is involved in complex II of the mitochondrial electron transport chain and is responsible for transferring electrons from succinate to ubiquinone (coenzyme Q).
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The quinone binding site (Q-site) of Mitochondrial Complex II (succinate-ubiquinone oxidoreductase) is the target for a number of inhibitors useful for elucidating the mechanism of the enzyme. Some of these have been developed as fungicides or pesticides, and species-specific Q-site inhibitors may be useful against human pathogens. We report structures of chicken Complex II with six different Q-site inhibitors bound, at resolutions 2.0-2.4 A. These structures show the common interactions between the inhibitors and their binding site. In every case a carbonyl or hydroxyl oxygen of the inhibitor is H-bonded to Tyr58 in subunit SdhD and Trp173 in subunit SdhB. Two of the inhibitors H-bond Ser39 in subunit SdhC directly, while two others do so via a water molecule. There is a distinct cavity that accepts the 2-substituent of the carboxylate ring in flutolanil and related inhibitors. A hydrophobic "tail pocket" opens to receive a side-chain of intermediate-length inhibitors. Shorter inhibitors fit entirely within the main binding cleft, while the long hydrophobic side chains of ferulenol and atpenin A5 protrude out of the cleft into the bulk lipid region, as presumably does that of ubiquinone. Comparison of mitochondrial and Escherichia coli Complex II shows a rotation of the membrane-anchor subunits by 7 degrees relative to the ironsulfur protein. This rotation alters the geometry of the Q-site and the H-bonding pattern of SdhB:His216 and SdhD:Asp57. This conformational difference, rather than any active-site mutation, may be responsible for the different inhibitor sensitivity of the bacterial enzyme.

Crystallographic investigation of the ubiquinone binding site of respiratory Complex II and its inhibitors.,Huang LS, Lummen P, Berry EA Biochim Biophys Acta Proteins Proteom. 2021 Sep;1869(9):140679. doi:, 10.1016/j.bbapap.2021.140679. Epub 2021 Jun 3. PMID:34089891<ref>PMID:34089891</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6myu" style="background-color:#fffaf0;"></div>

==See Also==
*[[Succinate dehydrogenase 3D structures|Succinate dehydrogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Gallus gallus]]
[[Category: Large Structures]]
[[Category: Berry EA]]
[[Category: Huang L-S]]