7scc: Difference between revisions
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[7scc]] is a 36 chain structure with sequence from [https://en.wikipedia.org/wiki/Synechocystis_sp._PCC_6803_substr._Kazusa Synechocystis sp. PCC 6803 substr. Kazusa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7SCC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7SCC FirstGlance]. <br> | <table><tr><td colspan='2'>[[7scc]] is a 36 chain structure with sequence from [https://en.wikipedia.org/wiki/Synechocystis_sp._PCC_6803_substr._Kazusa Synechocystis sp. PCC 6803 substr. Kazusa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7SCC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7SCC FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=45D:BETA,BETA-CAROTENE-4,4-DIONE'>45D</scene>, <scene name='pdbligand=CYC:PHYCOCYANOBILIN'>CYC</scene></td></tr> | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.6Å</td></tr> | ||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=45D:BETA,BETA-CAROTENE-4,4-DIONE'>45D</scene>, <scene name='pdbligand=CYC:PHYCOCYANOBILIN'>CYC</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=7scc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7scc OCA], [https://pdbe.org/7scc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7scc RCSB], [https://www.ebi.ac.uk/pdbsum/7scc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7scc ProSAT]</span></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=7scc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7scc OCA], [https://pdbe.org/7scc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7scc RCSB], [https://www.ebi.ac.uk/pdbsum/7scc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7scc ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
[https://www.uniprot.org/uniprot/PHAA_SYNY3 PHAA_SYNY3] Light-harvesting photosynthetic bile pigment-protein from the phycobiliprotein complex. Allophycocyanin has a maximum absorption at approximately 650 nanometers. | |||
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== Publication Abstract from PubMed == | |||
Phycobilisome (PBS) structures are elaborate antennae in cyanobacteria and red algae(1,2). These large protein complexes capture incident sunlight and transfer the energy through a network of embedded pigment molecules called bilins to the photosynthetic reaction centres. However, light harvesting must also be balanced against the risks of photodamage. A known mode of photoprotection is mediated by orange carotenoid protein (OCP), which binds to PBS when light intensities are high to mediate photoprotective, non-photochemical quenching(3-6). Here we use cryogenic electron microscopy to solve four structures of the 6.2 MDa PBS, with and without OCP bound, from the model cyanobacterium Synechocystis sp. PCC 6803. The structures contain a previously undescribed linker protein that binds to the membrane-facing side of PBS. For the unquenched PBS, the structures also reveal three different conformational states of the antenna, two previously unknown. The conformational states result from positional switching of two of the rods and may constitute a new mode of regulation of light harvesting. Only one of the three PBS conformations can bind to OCP, which suggests that not every PBS is equally susceptible to non-photochemical quenching. In the OCP-PBS complex, quenching is achieved through the binding of four 34 kDa OCPs organized as two dimers. The complex reveals the structure of the active form of OCP, in which an approximately 60 A displacement of its regulatory carboxy terminal domain occurs. Finally, by combining our structure with spectroscopic properties(7), we elucidate energy transfer pathways within PBS in both the quenched and light-harvesting states. Collectively, our results provide detailed insights into the biophysical underpinnings of the control of cyanobacterial light harvesting. The data also have implications for bioengineering PBS regulation in natural and artificial light-harvesting systems. | |||
Structures of a phycobilisome in light-harvesting and photoprotected states.,Dominguez-Martin MA, Sauer PV, Kirst H, Sutter M, Bina D, Greber BJ, Nogales E, Polivka T, Kerfeld CA Nature. 2022 Sep;609(7928):835-845. doi: 10.1038/s41586-022-05156-4. Epub 2022 , Aug 31. PMID:36045294<ref>PMID:36045294</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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<div class="pdbe-citations 7scc" style="background-color:#fffaf0;"></div> | |||
==See Also== | ==See Also== | ||
*[[Allophycocyanin 3D structures|Allophycocyanin 3D structures]] | *[[Allophycocyanin 3D structures|Allophycocyanin 3D structures]] | ||
== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||