View source for 2b7s


==R381K mutant of flavocytochrome c3==
<StructureSection load='2b7s' size='340' side='right'caption='[[2b7s]], [[Resolution|resolution]] 2.12&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2b7s]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Shewanella_frigidimarina Shewanella frigidimarina]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2B7S OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2B7S 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]] 2.12&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=FUM:FUMARIC+ACID'>FUM</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=2b7s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2b7s OCA], [https://pdbe.org/2b7s PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2b7s RCSB], [https://www.ebi.ac.uk/pdbsum/2b7s PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2b7s ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/FCCA_SHEFR FCCA_SHEFR] Flavocytochrome that catalyzes the reduction of fumarate to succinate (PubMed:10978153). Is essential for fumarate respiration during anaerobic growth, acting as the terminal reductase (By similarity). Receives electrons from the membrane-bound tetraheme c-type cytochrome CymA (By similarity). In vitro, can use the artificial electron donor methyl viologen (PubMed:10978153).[UniProtKB:P83223][UniProtKB:Q07WU7]<ref>PMID:10978153</ref> 
== 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/b7/2b7s_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=2b7s ConSurf].
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== Publication Abstract from PubMed ==
The mechanism for fumarate reduction by the soluble fumarate reductase from Shewanella frigidimarina involves hydride transfer from FAD and proton transfer from the active-site acid, Arg-402. It has been proposed that Arg-402 forms part of a proton transfer pathway that also involves Glu-378 and Arg-381 but, unusually, does not involve any bound water molecules. To gain further insight into the importance of this proton pathway we have perturbed it by substituting Arg-381 by lysine and methionine and Glu-378 by aspartate. Although all the mutant enzymes retain measurable activities, there are orders-of-magnitude decreases in their k(cat) values compared with the wild-type enzyme. Solvent kinetic isotope effects show that proton transfer is rate-limiting in the wild-type and mutant enzymes. Proton inventories indicate that the proton pathway involves multiple exchangeable groups. Fast scan protein-film voltammetric studies on wild-type and R381K enzymes show that the proton transfer pathway delivers one proton per catalytic cycle and is not required for transporting the other proton, which transfers as a hydride from the reduced, protonated FAD. The crystal structures of E378D and R381M mutant enzymes have been determined to 1.7 and 2.1 A resolution, respectively. They allow an examination of the structural changes that disturb proton transport. Taken together, the results indicate that Arg-381, Glu-378, and Arg-402 form a proton pathway that is completely conserved throughout the fumarate reductase/succinate dehydrogenase family of enzymes.

A proton delivery pathway in the soluble fumarate reductase from Shewanella frigidimarina.,Pankhurst KL, Mowat CG, Rothery EL, Hudson JM, Jones AK, Miles CS, Walkinshaw MD, Armstrong FA, Reid GA, Chapman SK J Biol Chem. 2006 Jul 21;281(29):20589-97. Epub 2006 May 12. PMID:16699170<ref>PMID:16699170</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 2b7s" style="background-color:#fffaf0;"></div>

==See Also==
*[[Flavocytochrome 3D structures|Flavocytochrome 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Shewanella frigidimarina]]
[[Category: Chapman SK]]
[[Category: Miles CS]]
[[Category: Mowat CG]]
[[Category: Pankhurst KL]]
[[Category: Reid GA]]
[[Category: Rothery EL]]
[[Category: Walkinshaw MD]]