View source for 1rg5


==Structure of the photosynthetic reaction centre from Rhodobacter sphaeroides carotenoidless strain R-26.1==
<StructureSection load='1rg5' size='340' side='right'caption='[[1rg5]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1rg5]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Rhodobacter_sphaeroides Rhodobacter sphaeroides]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1RG5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1RG5 FirstGlance]. <br>
</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=HTO:HEPTANE-1,2,3-TRIOL'>HTO</scene>, <scene name='pdbligand=LDA:LAURYL+DIMETHYLAMINE-N-OXIDE'>LDA</scene>, <scene name='pdbligand=U10:UBIQUINONE-10'>U10</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[4rcr|4rcr]], [[1rgn|1rgn]], [[1rqk|1rqk]]</div></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=1rg5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1rg5 OCA], [https://pdbe.org/1rg5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1rg5 RCSB], [https://www.ebi.ac.uk/pdbsum/1rg5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1rg5 ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/RCEL_RHOSH RCEL_RHOSH]] The reaction center is a membrane-bound complex that mediates the initial photochemical event in the electron transfer process of photosynthesis. [[https://www.uniprot.org/uniprot/RCEH_RHOSH RCEH_RHOSH]] The reaction center is a membrane-bound complex that mediates the initial photochemical event in the electron transfer process of photosynthesis. [[https://www.uniprot.org/uniprot/RCEM_RHOSH RCEM_RHOSH]] 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/rg/1rg5_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=1rg5 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 1rg5" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Rhodobacter sphaeroides]]
[[Category: Cogdell, R J]]
[[Category: Gardiner, A T]]
[[Category: Hashimoto, H]]
[[Category: Isaacs, N W]]
[[Category: Roszak, A W]]
[[Category: Carotenoid binding site]]
[[Category: Carotenoidless mutant]]
[[Category: Membrane protein]]
[[Category: Photosynthesis]]
[[Category: Photosynthetic reaction center]]