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== | ==Bovine heart cytochrome C oxidase in the fully reduced state== | ||
Cytochrome c oxidase transfers electrons and protons for dioxygen | <StructureSection load='2eij' size='340' side='right'caption='[[2eij]], [[Resolution|resolution]] 1.90Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[2eij]] is a 20 chain structure with sequence from [https://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2EIJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2EIJ 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]] 1.9Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CDL:CARDIOLIPIN'>CDL</scene>, <scene name='pdbligand=CHD:CHOLIC+ACID'>CHD</scene>, <scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=CUA:DINUCLEAR+COPPER+ION'>CUA</scene>, <scene name='pdbligand=DMU:DECYL-BETA-D-MALTOPYRANOSIDE'>DMU</scene>, <scene name='pdbligand=FME:N-FORMYLMETHIONINE'>FME</scene>, <scene name='pdbligand=HEA:HEME-A'>HEA</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene>, <scene name='pdbligand=PEK:(1S)-2-{[(2-AMINOETHOXY)(HYDROXY)PHOSPHORYL]OXY}-1-[(STEAROYLOXY)METHYL]ETHYL+(5E,8E,11E,14E)-ICOSA-5,8,11,14-TETRAENOATE'>PEK</scene>, <scene name='pdbligand=PGV:(1R)-2-{[{[(2S)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(PALMITOYLOXY)METHYL]ETHYL+(11E)-OCTADEC-11-ENOATE'>PGV</scene>, <scene name='pdbligand=PSC:(7R,17E,20E)-4-HYDROXY-N,N,N-TRIMETHYL-9-OXO-7-[(PALMITOYLOXY)METHYL]-3,5,8-TRIOXA-4-PHOSPHAHEXACOSA-17,20-DIEN-1-AMINIUM+4-OXIDE'>PSC</scene>, <scene name='pdbligand=SAC:N-ACETYL-SERINE'>SAC</scene>, <scene name='pdbligand=TGL:TRISTEAROYLGLYCEROL'>TGL</scene>, <scene name='pdbligand=TPO:PHOSPHOTHREONINE'>TPO</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=2eij FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2eij OCA], [https://pdbe.org/2eij PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2eij RCSB], [https://www.ebi.ac.uk/pdbsum/2eij PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2eij ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/COX1_BOVIN COX1_BOVIN] Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Subunits 1-3 form the functional core of the enzyme complex. CO I is the catalytic subunit of the enzyme. Electrons originating in cytochrome c are transferred via the copper A center of subunit 2 and heme A of subunit 1 to the bimetallic center formed by heme A3 and copper B. | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ei/2eij_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2eij ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Cytochrome c oxidase transfers electrons and protons for dioxygen reduction coupled with proton pumping. These electron and proton transfers are tightly coupled with each other for the effective energy transduction by various unknown mechanisms. Here, we report a coupling mechanism by a histidine (His-503) at the entrance of a proton transfer pathway to the dioxygen reduction site (D-pathway) of bovine heart cytochrome c oxidase. In the reduced state, a water molecule is fixed by hydrogen bonds between His-503 and Asp-91 of the D-pathway and is linked via two water arrays extending to the molecular surface. The microenvironment of Asp-91 appears in the x-ray structure to have a proton affinity as high as that of His-503. Thus, Asp-91 and His-503 cooperatively trap, on the fixed water molecule, the proton that is transferred through the water arrays from the molecular surface. On oxidation, the His-503 imidazole plane rotates by 180 degrees to break the hydrogen bond to the protonated water and releases the proton to Asp-91. On reduction, Asp-91 donates the proton to the dioxygen reduction site through the D-pathway. The proton collection controlled by His-503 was confirmed by partial electron transfer inhibition by binding of Zn2+ and Cd2+ to His-503 in the x-ray structures. The estimated Kd for Zn2+ binding to His-503 in the x-ray structure is consistent with the reported Kd for complete proton-pumping inhibition by Zn2+ [Kannt A, Ostermann T, Muller H, Ruitenberg M (2001) FEBS Lett 503:142-146]. These results suggest that His-503 couples the proton transfer for dioxygen reduction with the proton pumping. | |||
A histidine residue acting as a controlling site for dioxygen reduction and proton pumping by cytochrome c oxidase.,Muramoto K, Hirata K, Shinzawa-Itoh K, Yoko-o S, Yamashita E, Aoyama H, Tsukihara T, Yoshikawa S Proc Natl Acad Sci U S A. 2007 May 8;104(19):7881-6. Epub 2007 Apr 30. PMID:17470809<ref>PMID:17470809</ref> | |||
== | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
</div> | |||
<div class="pdbe-citations 2eij" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Cytochrome c oxidase 3D structures|Cytochrome c oxidase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Aoyama H]] | |||
[[Category: Aoyama | [[Category: Hirata K]] | ||
[[Category: Hirata | [[Category: Muramoto K]] | ||
[[Category: Muramoto | [[Category: Shinzawa-Itoh K]] | ||
[[Category: Shinzawa-Itoh | [[Category: Tsukihara T]] | ||
[[Category: Tsukihara | [[Category: Yamashita E]] | ||
[[Category: Yamashita | [[Category: Yoko-o S]] | ||
[[Category: Yoko- | [[Category: Yoshikawa S]] | ||
[[Category: Yoshikawa | |||
Latest revision as of 11:41, 25 October 2023
Bovine heart cytochrome C oxidase in the fully reduced stateBovine heart cytochrome C oxidase in the fully reduced state
Structural highlights
FunctionCOX1_BOVIN Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Subunits 1-3 form the functional core of the enzyme complex. CO I is the catalytic subunit of the enzyme. Electrons originating in cytochrome c are transferred via the copper A center of subunit 2 and heme A of subunit 1 to the bimetallic center formed by heme A3 and copper B. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedCytochrome c oxidase transfers electrons and protons for dioxygen reduction coupled with proton pumping. These electron and proton transfers are tightly coupled with each other for the effective energy transduction by various unknown mechanisms. Here, we report a coupling mechanism by a histidine (His-503) at the entrance of a proton transfer pathway to the dioxygen reduction site (D-pathway) of bovine heart cytochrome c oxidase. In the reduced state, a water molecule is fixed by hydrogen bonds between His-503 and Asp-91 of the D-pathway and is linked via two water arrays extending to the molecular surface. The microenvironment of Asp-91 appears in the x-ray structure to have a proton affinity as high as that of His-503. Thus, Asp-91 and His-503 cooperatively trap, on the fixed water molecule, the proton that is transferred through the water arrays from the molecular surface. On oxidation, the His-503 imidazole plane rotates by 180 degrees to break the hydrogen bond to the protonated water and releases the proton to Asp-91. On reduction, Asp-91 donates the proton to the dioxygen reduction site through the D-pathway. The proton collection controlled by His-503 was confirmed by partial electron transfer inhibition by binding of Zn2+ and Cd2+ to His-503 in the x-ray structures. The estimated Kd for Zn2+ binding to His-503 in the x-ray structure is consistent with the reported Kd for complete proton-pumping inhibition by Zn2+ [Kannt A, Ostermann T, Muller H, Ruitenberg M (2001) FEBS Lett 503:142-146]. These results suggest that His-503 couples the proton transfer for dioxygen reduction with the proton pumping. A histidine residue acting as a controlling site for dioxygen reduction and proton pumping by cytochrome c oxidase.,Muramoto K, Hirata K, Shinzawa-Itoh K, Yoko-o S, Yamashita E, Aoyama H, Tsukihara T, Yoshikawa S Proc Natl Acad Sci U S A. 2007 May 8;104(19):7881-6. Epub 2007 Apr 30. PMID:17470809[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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