View source for 1k6n


==E(L212)A,D(L213)A Double Mutant Structure of Photosynthetic Reaction Center from Rhodobacter Sphaeroides==
<StructureSection load='1k6n' size='340' side='right'caption='[[1k6n]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1k6n]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Cereibacter_sphaeroides Cereibacter sphaeroides]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1K6N OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1K6N 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]] 3.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BCL:BACTERIOCHLOROPHYLL+A'>BCL</scene>, <scene name='pdbligand=BPH:BACTERIOPHEOPHYTIN+A'>BPH</scene>, <scene name='pdbligand=CDL:CARDIOLIPIN'>CDL</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene>, <scene name='pdbligand=LDA:LAURYL+DIMETHYLAMINE-N-OXIDE'>LDA</scene>, <scene name='pdbligand=SPN:SPEROIDENONE'>SPN</scene>, <scene name='pdbligand=U10:UBIQUINONE-10'>U10</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=1k6n FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1k6n OCA], [https://pdbe.org/1k6n PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1k6n RCSB], [https://www.ebi.ac.uk/pdbsum/1k6n PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1k6n ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RCEL_CERSP RCEL_CERSP] The reaction center is a membrane-bound complex that mediates the initial photochemical event in the electron transfer process of photosynthesis.
== 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/k6/1k6n_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=1k6n ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
We report on the unexpected structural changes caused by substitution of acidic amino acids in the Q(B) binding pocket of the bacterial photosynthetic reaction center by alanines. The mutations targeted key residues L212Glu and L213Asp of this transmembrane protein-cofactor complex. The amino acid substitutions in the L212Ala-L213Ala mutant reaction center ("AA") were known to affect the delivery of protons after the light-induced generation of Q(B)(-), which renders the AA strain incapable of photosynthetic growth. The AA structure not only revealed side chain rearrangements but also showed movement of the main chain segments that are contiguous with the mutation sites. The alanine substitutions caused an expansion of the cavity rather than its collapse. In addition, Q(B) is found mainly in the binding site that is proximal to the iron-ligand complex (closest to Q(A)) as opposed to its distal binding site (furthest from Q(A)) in the structure of the wild-type reaction center. The observed rearrangements in the structure of the AA reaction center establish a new balance between charged residues of an interactive network near Q(B). This structurally and electrostatically altered complex forms the basis for future understanding of the structural basis for proton transfer in active reaction centers which retain the alanine substitutions but carry a distant compensatory mutation.

The structure of a mutant photosynthetic reaction center shows unexpected changes in main chain orientations and quinone position.,Pokkuluri PR, Laible PD, Deng YL, Wong TN, Hanson DK, Schiffer M Biochemistry. 2002 May 14;41(19):5998-6007. PMID:11993994<ref>PMID:11993994</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1k6n" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cereibacter sphaeroides]]
[[Category: Large Structures]]
[[Category: Deng Y-L]]
[[Category: Hanson DK]]
[[Category: Laible PD]]
[[Category: Pokkuluri PR]]
[[Category: Schiffer M]]
[[Category: Wong TN]]