View source for 7yca


==Cryo-EM structure of the PSI-LHCI-Lhcp supercomplex from Ostreococcus tauri==
<StructureSection load='7yca' size='340' side='right'caption='[[7yca]], [[Resolution|resolution]] 2.94&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7yca]] is a 17 chain structure with sequence from [https://en.wikipedia.org/wiki/Ostreococcus_tauri Ostreococcus tauri]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7YCA OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7YCA 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]] 2.94&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACE:ACETYL+GROUP'>ACE</scene>, <scene name='pdbligand=BCR:BETA-CAROTENE'>BCR</scene>, <scene name='pdbligand=CLA:CHLOROPHYLL+A'>CLA</scene>, <scene name='pdbligand=DGD:DIGALACTOSYL+DIACYL+GLYCEROL+(DGDG)'>DGD</scene>, <scene name='pdbligand=IWJ:(3~{E},5~{E},7~{E},9~{E},11~{E},13~{E},15~{E},17~{E})-1-[(1~{S},4~{S})-2,2-dimethyl-6-methylidene-1,4-bis(oxidanyl)cyclohexyl]-3,7,12,16-tetramethyl-18-[(1~{R},4~{R})-2,6,6-trimethyl-4-oxidanyl-cyclohex-2-en-1-yl]octadeca-3,5,7,9,11,13,15,17-octaen-2-one'>IWJ</scene>, <scene name='pdbligand=KC2:(2E)-3-[(21R)-9,14-diethenyl-21-(methoxycarbonyl)-4,8,13,18-tetramethyl-20-oxo-3,4-didehydrophorbin-3-yl-kappa~2~N~23~,N~25~]prop-2-enoato(2-)magnesium'>KC2</scene>, <scene name='pdbligand=LHG:1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE'>LHG</scene>, <scene name='pdbligand=LMG:1,2-DISTEAROYL-MONOGALACTOSYL-DIGLYCERIDE'>LMG</scene>, <scene name='pdbligand=NEX:(1R,3S)-6-[(5E,7E,9E,11E,13E,15Z,17E)-18-[(1R,3S,6S)-3-hydroxy-1,5,5-trimethyl-7-oxabicyclo[4.1.0]heptan-6-yl]-3,7,12,16-tetramethyl-octadeca-1,3,5,7,9,11,13,15,17-nonaenylidene]-1,5,5-trimethyl-cyclohexane-1,3-diol'>NEX</scene>, <scene name='pdbligand=PQN:PHYLLOQUINONE'>PQN</scene>, <scene name='pdbligand=Q6L:(1~{S})-3,5,5-trimethyl-4-[(3~{E},5~{E},7~{E},9~{E},11~{E},13~{E},15~{E},17~{E})-3,7,12,16-tetramethyl-18-[(1~{R},4~{R})-2,6,6-trimethyl-4-oxidanyl-cyclohex-2-en-1-yl]octadeca-3,5,7,9,11,13,15,17-octaenyl]cyclohex-3-en-1-ol'>Q6L</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=TPO:PHOSPHOTHREONINE'>TPO</scene>, <scene name='pdbligand=XAT:(3S,5R,6S,3S,5R,6S)-5,6,5,6-DIEPOXY-5,6,5,6-+TETRAHYDRO-BETA,BETA-CAROTENE-3,3-DIOL'>XAT</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=7yca FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7yca OCA], [https://pdbe.org/7yca PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7yca RCSB], [https://www.ebi.ac.uk/pdbsum/7yca PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7yca ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q3B9U5_OSTTA Q3B9U5_OSTTA] The light-harvesting complex (LHC) functions as a light receptor, it captures and delivers excitation energy to photosystems with which it is closely associated.[RuleBase:RU363080]
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
As a ubiquitous picophytoplankton in the ocean and an early-branching green alga, Ostreococcus tauri is a model prasinophyte species for studying the functional evolution of the light-harvesting systems in photosynthesis. Here, we report the structure and function of the O. tauri photosystem I (PSI) supercomplex in low light conditions, where it expands its photon-absorbing capacity by assembling with the light-harvesting complexes I (LHCI) and a prasinophyte-specific light-harvesting complex (Lhcp). The architecture of the supercomplex exhibits hybrid features of the plant-type and the green algal-type PSI supercomplexes, consisting of a PSI core, an Lhca1-Lhca4-Lhca2-Lhca3 belt attached on one side and an Lhca5-Lhca6 heterodimer associated on the other side between PsaG and PsaH. Interestingly, nine Lhcp subunits, including one Lhcp1 monomer with a phosphorylated amino-terminal threonine and eight Lhcp2 monomers, oligomerize into three trimers and associate with PSI on the third side between Lhca6 and PsaK. The Lhcp1 phosphorylation and the light-harvesting capacity of PSI were subjected to reversible photoacclimation, suggesting that the formation of OtPSI-LHCI-Lhcp supercomplex is likely due to a phosphorylation-dependent mechanism induced by changes in light intensity. Notably, this supercomplex did not exhibit far-red peaks in the 77 K fluorescence spectra, which is possibly due to the weak coupling of the chlorophyll a603-a609 pair in OtLhca1-4.

The photosystem I supercomplex from a primordial green alga Ostreococcus tauri harbors three light-harvesting complex trimers.,Ishii A, Shan J, Sheng X, Kim E, Watanabe A, Yokono M, Noda C, Song C, Murata K, Liu Z, Minagawa J Elife. 2023 Mar 23;12:e84488. doi: 10.7554/eLife.84488. PMID:36951548<ref>PMID:36951548</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7yca" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Ostreococcus tauri]]
[[Category: Ishii A]]
[[Category: Liu Z]]
[[Category: Minagawa J]]
[[Category: Murata K]]
[[Category: Shan J]]
[[Category: Sheng X]]
[[Category: Song C]]
[[Category: Watanabe A]]