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The | ==X-ray Structure of photosystem I-LHCI super complex from Chlamydomonas reinhardtii.== | ||
<StructureSection load='8h2u' size='340' side='right'caption='[[8h2u]], [[Resolution|resolution]] 3.40Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[8h2u]] is a 10 chain structure with sequence from [https://en.wikipedia.org/wiki/Chlamydomonas_reinhardtii Chlamydomonas reinhardtii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8H2U OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8H2U FirstGlance]. <br> | |||
</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=CHL:CHLOROPHYLL+B'>CHL</scene>, <scene name='pdbligand=CLA:CHLOROPHYLL+A'>CLA</scene>, <scene name='pdbligand=DGD:DIGALACTOSYL+DIACYL+GLYCEROL+(DGDG)'>DGD</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=LMT:DODECYL-BETA-D-MALTOSIDE'>LMT</scene>, <scene name='pdbligand=LUT:(3R,3R,6S)-4,5-DIDEHYDRO-5,6-DIHYDRO-BETA,BETA-CAROTENE-3,3-DIOL'>LUT</scene>, <scene name='pdbligand=PQN:PHYLLOQUINONE'>PQN</scene>, <scene name='pdbligand=SF4:IRON/SULFUR+CLUSTER'>SF4</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=8h2u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8h2u OCA], [https://pdbe.org/8h2u PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8h2u RCSB], [https://www.ebi.ac.uk/pdbsum/8h2u PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8h2u ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/Q75VY4_CHLRE Q75VY4_CHLRE] 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 == | |||
Photosystem I (PSI) from the green alga Chlamydomonas reinhardtii, with various numbers of membrane bound antenna complexes (LHCI), has been described in great detail. In contrast, structural characterization of soluble binding partners is less advanced. Here, we used X-ray crystallography and single particle cryo-EM to investigate three structures of the PSI-LHCI supercomplex from Chlamydomonas reinhardtii. An X-ray structure demonstrates the absence of six chlorophylls from the luminal side of the LHCI belts, suggesting these pigments were either physically absent or less stably associated with the complex, potentially influencing excitation transfer significantly. CryoEM revealed extra densities on luminal and stromal sides of the supercomplex, situated in the vicinity of the electron transfer sites. These densities disappeared after the binding of oxidized ferredoxin to PSI-LHCI. Based on these structures, we propose the existence of a PSI-LHCI resting state with a reduced active chlorophyll content, electron donors docked in waiting positions and regulatory binding partners positioned at the electron acceptor site. The resting state PSI-LHCI supercomplex would be recruited to its active form by the availability of oxidized ferredoxin. | |||
Three structures of PSI-LHCI from Chlamydomonas reinhardtii suggest a resting state re-activated by ferredoxin.,Gerle C, Misumi Y, Kawamoto A, Tanaka H, Kawai-Kubota H, Tokutsu R, Kim E, Chorev D, Abe K, Robinson CV, Mitsuoka K, Minagawa J, Kurisu G Biochim Biophys Acta Bioenerg. 2023 Jun 1:148986. doi: , 10.1016/j.bbabio.2023.148986. PMID:37270022<ref>PMID:37270022</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
[[Category: | <div class="pdbe-citations 8h2u" style="background-color:#fffaf0;"></div> | ||
[[Category: | == References == | ||
[[Category: | <references/> | ||
[[Category: | __TOC__ | ||
</StructureSection> | |||
[[Category: Chlamydomonas reinhardtii]] | |||
[[Category: Large Structures]] | |||
[[Category: Kubota-Kawai H]] | |||
[[Category: Kurisu G]] | |||
[[Category: Misumi Y]] | |||
[[Category: Tanaka H]] | |||
Revision as of 11:19, 14 June 2023
X-ray Structure of photosystem I-LHCI super complex from Chlamydomonas reinhardtii.X-ray Structure of photosystem I-LHCI super complex from Chlamydomonas reinhardtii.
Structural highlights
FunctionQ75VY4_CHLRE 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] Publication Abstract from PubMedPhotosystem I (PSI) from the green alga Chlamydomonas reinhardtii, with various numbers of membrane bound antenna complexes (LHCI), has been described in great detail. In contrast, structural characterization of soluble binding partners is less advanced. Here, we used X-ray crystallography and single particle cryo-EM to investigate three structures of the PSI-LHCI supercomplex from Chlamydomonas reinhardtii. An X-ray structure demonstrates the absence of six chlorophylls from the luminal side of the LHCI belts, suggesting these pigments were either physically absent or less stably associated with the complex, potentially influencing excitation transfer significantly. CryoEM revealed extra densities on luminal and stromal sides of the supercomplex, situated in the vicinity of the electron transfer sites. These densities disappeared after the binding of oxidized ferredoxin to PSI-LHCI. Based on these structures, we propose the existence of a PSI-LHCI resting state with a reduced active chlorophyll content, electron donors docked in waiting positions and regulatory binding partners positioned at the electron acceptor site. The resting state PSI-LHCI supercomplex would be recruited to its active form by the availability of oxidized ferredoxin. Three structures of PSI-LHCI from Chlamydomonas reinhardtii suggest a resting state re-activated by ferredoxin.,Gerle C, Misumi Y, Kawamoto A, Tanaka H, Kawai-Kubota H, Tokutsu R, Kim E, Chorev D, Abe K, Robinson CV, Mitsuoka K, Minagawa J, Kurisu G Biochim Biophys Acta Bioenerg. 2023 Jun 1:148986. doi: , 10.1016/j.bbabio.2023.148986. PMID:37270022[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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