View source for 7pqd


==Cryo-EM structure of the dimeric Rhodobacter sphaeroides RC-LH1 core complex at 2.9 A: the structural basis for dimerisation==
<StructureSection load='7pqd' size='340' side='right'caption='[[7pqd]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7pqd]] is a 70 chain structure with sequence from [https://en.wikipedia.org/wiki/Cereibacter_sphaeroides_2.4.1 Cereibacter sphaeroides 2.4.1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7PQD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7PQD FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=3PE:1,2-DIACYL-SN-GLYCERO-3-PHOSPHOETHANOLAMINE'>3PE</scene>, <scene name='pdbligand=BCL:BACTERIOCHLOROPHYLL+A'>BCL</scene>, <scene name='pdbligand=BPH:BACTERIOPHEOPHYTIN+A'>BPH</scene>, <scene name='pdbligand=CD4:(2R,5R,11R,14R)-5,8,11-TRIHYDROXY-5,11-DIOXIDO-17-OXO-2,14-BIS(TETRADECANOYLOXY)-4,6,10,12,16-PENTAOXA-5,11-DIPHOSPHATRIACONT-1-YL+TETRADECANOATE'>CD4</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene>, <scene name='pdbligand=FME:N-FORMYLMETHIONINE'>FME</scene>, <scene name='pdbligand=LMT:DODECYL-BETA-D-MALTOSIDE'>LMT</scene>, <scene name='pdbligand=SP2:3,4-DIHYDROSPHEROIDENE'>SP2</scene>, <scene name='pdbligand=SQD:1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL'>SQD</scene>, <scene name='pdbligand=U10:UBIQUINONE-10'>U10</scene>, <scene name='pdbligand=UQ1:UBIQUINONE-1'>UQ1</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=7pqd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7pqd OCA], [https://pdbe.org/7pqd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7pqd RCSB], [https://www.ebi.ac.uk/pdbsum/7pqd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7pqd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/RCEM_CERS4 RCEM_CERS4] The reaction center is a membrane-bound complex that mediates the initial photochemical event in the electron transfer process of photosynthesis.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The dimeric reaction centre light-harvesting 1 (RC-LH1) core complex of Rhodobacter sphaeroides converts absorbed light energy to a charge separation, and then it reduces a quinone electron and proton acceptor to a quinol. The angle between the two monomers imposes a bent configuration on the dimer complex, which exerts a major influence on the curvature of the membrane vesicles, known as chromatophores, where the light-driven photosynthetic reactions take place. To investigate the dimerisation interface between two RC-LH1 monomers, we determined the cryogenic electron microscopy structure of the dimeric complex at 2.9 A resolution. The structure shows that each monomer consists of a central RC partly enclosed by a 14-subunit LH1 ring held in an open state by PufX and protein-Y polypeptides, thus enabling quinones to enter and leave the complex. Two monomers are brought together through N-terminal interactions between PufX polypeptides on the cytoplasmic side of the complex, augmented by two novel transmembrane polypeptides, designated protein-Z, that bind to the outer faces of the two central LH1 beta polypeptides. The precise fit at the dimer interface, enabled by PufX and protein-Z, by C-terminal interactions between opposing LH1 alphabeta subunits, and by a series of interactions with a bound sulfoquinovosyl diacylglycerol lipid, bring together each monomer creating an S-shaped array of 28 bacteriochlorophylls. The seamless join between the two sets of LH1 bacteriochlorophylls provides a path for excitation energy absorbed by one half of the complex to migrate across the dimer interface to the other half.

Cryo-EM structure of the dimeric Rhodobacter sphaeroides RC-LH1 core complex at 2.9 A: the structural basis for dimerisation.,Qian P, Croll TI, Hitchcock A, Jackson PJ, Salisbury JH, Castro-Hartmann P, Sader K, Swainsbury DJK, Hunter CN Biochem J. 2021 Nov 12;478(21):3923-3937. doi: 10.1042/BCJ20210696. PMID:34622934<ref>PMID:34622934</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7pqd" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cereibacter sphaeroides 2 4.1]]
[[Category: Large Structures]]
[[Category: Hunter CN]]
[[Category: Qian P]]