View source for 6vpv


==Trimeric Photosystem I from the High-Light Tolerant Cyanobacteria Cyanobacterium Aponinum==
<StructureSection load='6vpv' size='340' side='right'caption='[[6vpv]], [[Resolution|resolution]] 2.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6vpv]] is a 30 chain structure with sequence from [https://en.wikipedia.org/wiki/Cyanobacterium_aponinum_0216 Cyanobacterium aponinum 0216]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6VPV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6VPV 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]] 2.7&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BCR:BETA-CAROTENE'>BCR</scene>, <scene name='pdbligand=CLA:CHLOROPHYLL+A'>CLA</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=PQN:PHYLLOQUINONE'>PQN</scene>, <scene name='pdbligand=SQD:1,2-DI-O-ACYL-3-O-[6-DEOXY-6-SULFO-ALPHA-D-GLUCOPYRANOSYL]-SN-GLYCEROL'>SQD</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=6vpv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6vpv OCA], [https://pdbe.org/6vpv PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6vpv RCSB], [https://www.ebi.ac.uk/pdbsum/6vpv PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6vpv ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/K9Z0B2_CYAAP K9Z0B2_CYAAP] PsaA and PsaB bind P700, the primary electron donor of photosystem I (PSI), as well as the electron acceptors A0, A1 and FX. PSI is a plastocyanin/cytochrome c6-ferredoxin oxidoreductase, converting photonic excitation into a charge separation, which transfers an electron from the donor P700 chlorophyll pair to the spectroscopically characterized acceptors A0, A1, FX, FA and FB in turn. Oxidized P700 is reduced on the lumenal side of the thylakoid membrane by plastocyanin or cytochrome c6.[ARBA:ARBA00002612][HAMAP-Rule:MF_00458]  PsaA and psaB bind P700, the primary electron donor of photosystem I (PSI), as well as the electron acceptors A0, A1 and FX.[RuleBase:RU003775]
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== Publication Abstract from PubMed ==
Photosynthetic organisms have adapted to survive a myriad of extreme environments from the earth's deserts to its poles, yet the proteins that carry out the light reactions of photosynthesis are highly conserved from the cyanobacteria to modern day crops. To investigate adaptations of the photosynthetic machinery in cyanobacteria to excessive light stress, we isolated a new strain of cyanobacteria, Cyanobacterium aponinum 0216, from the extreme light environment of the Sonoran Desert. Here we report the biochemical characterization and the 2.7 A resolution structure of trimeric photosystem I from this high-light-tolerant cyanobacterium. The structure shows a new conformation of the PsaL C-terminus that supports trimer formation of cyanobacterial photosystem I. The spectroscopic analysis of this photosystem I revealed a decrease in far-red absorption, which is attributed to a decrease in the number of long- wavelength chlorophylls. Using these findings, we constructed two chimeric PSIs in Synechocystis sp. PCC 6803 demonstrating how unique structural features in photosynthetic complexes can change spectroscopic properties, allowing organisms to thrive under different environmental stresses.

The structure of photosystem I from a high-light-tolerant cyanobacteria.,Dobson Z, Ahad S, Vanlandingham J, Toporik H, Vaughn N, Vaughn M, Williams D, Reppert M, Fromme P, Mazor Y Elife. 2021 Aug 26;10:e67518. doi: 10.7554/eLife.67518. PMID:34435952<ref>PMID:34435952</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 6vpv" style="background-color:#fffaf0;"></div>

==See Also==
*[[Photosystem I 3D structures|Photosystem I 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cyanobacterium aponinum 0216]]
[[Category: Large Structures]]
[[Category: Dobson Z]]
[[Category: Fromme P]]
[[Category: Lin S]]
[[Category: Mazor Y]]
[[Category: Toporik H]]
[[Category: Vaughn N]]
[[Category: Williams D]]