View source for 4he8


==Crystal structure of the membrane domain of respiratory complex I from Thermus thermophilus==
<StructureSection load='4he8' size='340' side='right'caption='[[4he8]], [[Resolution|resolution]] 3.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4he8]] is a 14 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermus_thermophilus_HB8 Thermus thermophilus HB8]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HE8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HE8 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]] 3.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=4he8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4he8 OCA], [https://pdbe.org/4he8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4he8 RCSB], [https://www.ebi.ac.uk/pdbsum/4he8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4he8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NQO7_THET8 NQO7_THET8] NDH-1 shuttles electrons from NADH, via FMN and iron-sulfur (Fe-S) centers, to quinones in the respiratory chain. The immediate electron acceptor for the enzyme in this species is menaquinone. Couples the redox reaction to proton translocation (for every two electrons transferred, four hydrogen ions are translocated across the cytoplasmic membrane), and thus conserves the redox energy in a proton gradient required for the synthesis of ATP.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Complex I is the first and largest enzyme of the respiratory chain and has a central role in cellular energy production through the coupling of NADH:ubiquinone electron transfer to proton translocation. It is also implicated in many common human neurodegenerative diseases. Here, we report the first crystal structure of the entire, intact complex I (from Thermus thermophilus) at 3.3 A resolution. The structure of the 536-kDa complex comprises 16 different subunits, with a total of 64 transmembrane helices and 9 iron-sulphur clusters. The core fold of subunit Nqo8 (ND1 in humans) is, unexpectedly, similar to a half-channel of the antiporter-like subunits. Small subunits nearby form a linked second half-channel, which completes the fourth proton-translocation pathway (present in addition to the channels in three antiporter-like subunits). The quinone-binding site is unusually long, narrow and enclosed. The quinone headgroup binds at the deep end of this chamber, near iron-sulphur cluster N2. Notably, the chamber is linked to the fourth channel by a 'funnel' of charged residues. The link continues over the entire membrane domain as a flexible central axis of charged and polar residues, and probably has a leading role in the propagation of conformational changes, aided by coupling elements. The structure suggests that a unique, out-of-the-membrane quinone-reaction chamber enables the redox energy to drive concerted long-range conformational changes in the four antiporter-like domains, resulting in translocation of four protons per cycle.

Crystal structure of the entire respiratory complex I.,Baradaran R, Berrisford JM, Minhas GS, Sazanov LA Nature. 2013 Feb 28;494(7438):443-8. doi: 10.1038/nature11871. Epub 2013 Feb 17. PMID:23417064<ref>PMID:23417064</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 4he8" style="background-color:#fffaf0;"></div>

==See Also==
*[[NADH-quinone oxidoreductase|NADH-quinone oxidoreductase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermus thermophilus HB8]]
[[Category: Baradaran R]]
[[Category: Berrisford JM]]
[[Category: Minhas GS]]
[[Category: Sazanov LA]]