View source for 1aqe


==CRYSTAL STRUCTURE OF THE Y73E MUTANT OF CYTOCHROME C OF CLASS III (AMBLER) 26 KD==
<StructureSection load='1aqe' size='340' side='right'caption='[[1aqe]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1aqe]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Desulfomicrobium_norvegicum Desulfomicrobium norvegicum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AQE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1AQE 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1aqe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1aqe OCA], [https://pdbe.org/1aqe PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1aqe RCSB], [https://www.ebi.ac.uk/pdbsum/1aqe PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1aqe ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CYC32_DESNO CYC32_DESNO] Participates in sulfate respiration coupled with phosphorylation by transferring electrons from the enzyme dehydrogenase to ferredoxin.
== 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/aq/1aqe_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1aqe ConSurf].
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== Publication Abstract from PubMed ==
A combination of structural, kinetic, and interaction experiments has been used to study the role of a highly conserved aromatic residue, Tyr73, parallel to the sixth heme axial ligand of heme 4 in multiheme cytochrome c3 (Mr = 26 000), also called cytochrome cc3 or octaheme cytochrome, from Desulfovibrio desulfuricans Norway. This residue is expected to be involved in intermolecular electron transfer and protein-protein interaction, since heme 4 is described to be the interaction site between physiological partners. The kinetic experiments show that the Y73E replacement provokes no significant change in the electron-transfer reaction with the physiological partner, the [NiFeSe] hydrogenase, but that the protein-protein interaction between cytochrome c3 (Mr = 26 000) and hydrogenase is strongly affected by the mutation. The aromatic residue does not play a role in maintaining the axial heme ligand in a particular orientation, since the mutation did not affect the orientation of histidine 77, the sixth axial ligand of heme 4. The structural analysis by X-ray crystallography clearly shows that a rearrangement of the charged residues in the vicinity of the mutation site is responsible for the change in protein-protein interaction, which is of an electrostatic nature. Lys22 and Arg66, residues which are located at the interacting surface, are twisted toward the mutated position Glu73 in order to compensate for the negative charge and therefore are no longer accessible for the docking with a physiological partner. Tyr73 has instead a structural function and probably a role in maintaining the hydrophobic environment of the heme 4 cavity rather than a function in the intermolecular electron transfer with the physiological partners.

Structural and kinetic studies of the Y73E mutant of octaheme cytochrome c3 (Mr = 26 000) from Desulfovibrio desulfuricans Norway.,Aubert C, Giudici-Orticoni MT, Czjzek M, Haser R, Bruschi M, Dolla A Biochemistry. 1998 Feb 24;37(8):2120-30. PMID:9485359<ref>PMID:9485359</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 1aqe" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cytochrome C 3D structures|Cytochrome C 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Desulfomicrobium norvegicum]]
[[Category: Large Structures]]
[[Category: Czjzek M]]
[[Category: Haser R]]