View source for 8hjv


==Cryo-EM structure of carotenoid-depleted RC-LH complex from Roseiflexus castenholzii at 10,000 lux==
<StructureSection load='8hjv' size='340' side='right'caption='[[8hjv]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8hjv]] is a 35 chain structure with sequence from [https://en.wikipedia.org/wiki/Roseiflexus_castenholzii_DSM_13941 Roseiflexus castenholzii DSM 13941]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8HJV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8HJV FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[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=BPH:BACTERIOPHEOPHYTIN+A'>BPH</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=KGD:3-[(1~{E},3~{E},5~{E},7~{E},9~{E},11~{E},13~{E},15~{E},17~{E},19~{E})-3,7,12,16,20,24-hexamethylpentacosa-1,3,5,7,9,11,13,15,17,19,23-undecaenyl]-2,4,4-trimethyl-cyclohex-2-en-1-one'>KGD</scene>, <scene name='pdbligand=MQE:2-methyl-3-[(2E,6E,10E,14E,18E,22E,26E,30E,34E,38E)-3,7,11,15,19,23,27,31,35,39,43-undecamethyltetratetraconta-2,6,10,14,18,22,26,30,34,38,42-undecaen-1-yl]naphthalene-1,4-dione'>MQE</scene>, <scene name='pdbligand=PGV:(1R)-2-{[{[(2S)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(PALMITOYLOXY)METHYL]ETHYL+(11E)-OCTADEC-11-ENOATE'>PGV</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=8hjv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8hjv OCA], [https://pdbe.org/8hjv PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8hjv RCSB], [https://www.ebi.ac.uk/pdbsum/8hjv PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8hjv ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/A7NQE9_ROSCS A7NQE9_ROSCS] Antenna complexes are light-harvesting systems, which transfer the excitation energy to the reaction centers.[ARBA:ARBA00002455]
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Carotenoid (Car) pigments perform central roles in photosynthesis-related light harvesting (LH), photoprotection, and assembly of functional pigment-protein complexes. However, the relationships between Car depletion in the LH, assembly of the prokaryotic reaction center (RC)-LH complex, and quinone exchange are not fully understood. Here, we analyzed native RC-LH (nRC-LH) and Car-depleted RC-LH (dRC-LH) complexes in Roseiflexus castenholzii, a chlorosome-less filamentous anoxygenic phototroph that forms the deepest branch of photosynthetic bacteria. Newly identified exterior Cars functioned with the bacteriochlorophyll B800 to block the proposed quinone channel between LHalphabeta subunits in the nRC-LH, forming a sealed LH ring that was disrupted by transmembrane helices from cytochrome c and subunit X to allow quinone shuttling. dRC-LH lacked subunit X, leading to an exposed LH ring with a larger opening, which together accelerated the quinone exchange rate. We also assigned amino acid sequences of subunit X and two hypothetical proteins Y and Z that functioned in forming the quinone channel and stabilizing the RC-LH interactions. This study reveals the structural basis by which Cars assembly regulates the architecture and quinone exchange of bacterial RC-LH complexes. These findings mark an important step forward in understanding the evolution and diversity of prokaryotic photosynthetic apparatus.

Carotenoid assembly regulates quinone diffusion and the Roseiflexus castenholzii reaction center-light harvesting complex architecture.,Xin J, Shi Y, Zhang X, Yuan X, Xin Y, He H, Shen J, Blankenship RE, Xu X Elife. 2023 Sep 22;12:e88951. doi: 10.7554/eLife.88951. PMID:37737710<ref>PMID:37737710</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8hjv" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Roseiflexus castenholzii DSM 13941]]
[[Category: Xin J]]
[[Category: Xu X]]