View source for 1rqk


==Structure of the reaction centre from Rhodobacter sphaeroides carotenoidless strain R-26.1 reconstituted with 3,4-dihydrospheroidene==
<StructureSection load='1rqk' size='340' side='right'caption='[[1rqk]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1rqk]] 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=1RQK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1RQK 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]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><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=SP2:3,4-DIHYDROSPHEROIDENE'>SP2</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=1rqk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1rqk OCA], [https://pdbe.org/1rqk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1rqk RCSB], [https://www.ebi.ac.uk/pdbsum/1rqk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1rqk 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/rq/1rqk_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=1rqk ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
X-ray diffraction was used to determine high-resolution structures of the reaction center (RC) complex from the carotenoidless mutant, Rb. sphaeroides R-26.1, without or reconstituted with carotenoids. The results are compared with the structure of the RC from a semiaerobically grown Rb. sphaeroides strain 2.4.1. The investigation reveals the structure of the carotenoid in the different protein preparations, the nature of its binding site, and a plausible mechanism by which the carotenoid is incorporated unidirectionally in its characteristic geometric configuration. The structural data suggest that the accessibility of the carotenoid to the binding site is controlled by a specific "gatekeeper" residue which allows the carotenoid to approach the binding site from only one direction. Carotenoid binding to the protein is secured by hydrogen bonding to a separate "locking" amino acid. The study reveals the specific molecular interactions that control how the carotenoid protects the photosynthetic apparatus against photo-induced oxidative destruction.

Protein regulation of carotenoid binding; gatekeeper and locking amino acid residues in reaction centers of Rhodobacter sphaeroides.,Roszak AW, McKendrick K, Gardiner AT, Mitchell IA, Isaacs NW, Cogdell RJ, Hashimoto H, Frank HA Structure. 2004 May;12(5):765-73. PMID:15130469<ref>PMID:15130469</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 1rqk" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cereibacter sphaeroides]]
[[Category: Large Structures]]
[[Category: Cogdell RJ]]
[[Category: Gardiner AT]]
[[Category: Hashimoto H]]
[[Category: Isaacs NW]]
[[Category: Roszak AW]]