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| | ==Cryo-EM structure of the tetrameric photosystem I from a heterocyst-forming cyanobacterium Anabaena sp. PCC7120== | | ==Cryo-EM structure of the tetrameric photosystem I from a heterocyst-forming cyanobacterium Anabaena sp. PCC7120== |
| - | <StructureSection load='6k61' size='340' side='right'caption='[[6k61]], [[Resolution|resolution]] 2.37Å' scene=''> | + | <SX load='6k61' size='340' side='right' viewer='molstar' caption='[[6k61]], [[Resolution|resolution]] 2.37Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6k61]] is a 24 chain structure with sequence from [http://en.wikipedia.org/wiki/Nostoc_sp._pcc_7120 Nostoc sp. pcc 7120]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6K61 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6K61 FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6k61]] is a 20 chain structure with sequence from [https://en.wikipedia.org/wiki/Nostoc_sp._PCC_7120_=_FACHB-418 Nostoc sp. PCC 7120 = FACHB-418]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6K61 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6K61 FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BCR:BETA-CAROTENE'>BCR</scene>, <scene name='pdbligand=CL0:CHLOROPHYLL+A+ISOMER'>CL0</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=SF4:IRON/SULFUR+CLUSTER'>SF4</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> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 2.37Å</td></tr> |
| - | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Photosystem_I Photosystem I], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.97.1.12 1.97.1.12] </span></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=CL0:CHLOROPHYLL+A+ISOMER'>CL0</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=SF4:IRON/SULFUR+CLUSTER'>SF4</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'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6k61 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6k61 OCA], [http://pdbe.org/6k61 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6k61 RCSB], [http://www.ebi.ac.uk/pdbsum/6k61 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6k61 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=6k61 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6k61 OCA], [https://pdbe.org/6k61 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6k61 RCSB], [https://www.ebi.ac.uk/pdbsum/6k61 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6k61 ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/PSAE_NOSS1 PSAE_NOSS1]] Stabilizes the interaction between PsaC and the PSI core, assists the docking of the ferredoxin to PSI and interacts with ferredoxin-NADP oxidoreductase. [[http://www.uniprot.org/uniprot/PSAB1_NOSS1 PSAB1_NOSS1]] 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 (By similarity). [[http://www.uniprot.org/uniprot/PSAF_NOSS1 PSAF_NOSS1]] Probably participates in efficiency of electron transfer from plastocyanin to P700 (or cytochrome c553 in algae and cyanobacteria). This plastocyanin-docking protein contributes to the specific association of plastocyanin to PSI. [[http://www.uniprot.org/uniprot/PSAJ_NOSS1 PSAJ_NOSS1]] May help in the organization of the PsaE and PsaF subunits. [[http://www.uniprot.org/uniprot/PSAA_NOSS1 PSAA_NOSS1]] 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. [[http://www.uniprot.org/uniprot/PSAC_NOSS1 PSAC_NOSS1]] Apoprotein for the two 4Fe-4S centers FA and FB of photosystem I (PSI); essential for photochemical activity. FB is the terminal electron acceptor of PSI, donating electrons to ferredoxin. The C-terminus interacts with PsaA/B/D and helps assemble the protein into the PSI complex. Required for binding of PsaD and PsaE to PSI. 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.[HAMAP-Rule:MF_01303] [[http://www.uniprot.org/uniprot/PSAI_NOSS1 PSAI_NOSS1]] May help in the organization of the PsaL subunit. [[http://www.uniprot.org/uniprot/PSAD_NOSS1 PSAD_NOSS1]] PsaD can form complexes with ferredoxin and ferredoxin-oxidoreductase in photosystem I (PS I) reaction center. | + | [https://www.uniprot.org/uniprot/PSAA_NOSS1 PSAA_NOSS1] 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. |
| - | <div style="background-color:#fffaf0;">
| + | |
| - | == Publication Abstract from PubMed ==
| + | |
| - | Two large protein-cofactor complexes, photosystem I and photosystem II, are the central components of photosynthesis in the thylakoid membranes. Here, we report the 2.37-A structure of a tetrameric photosystem I complex from a heterocyst-forming cyanobacterium Anabaena sp. PCC 7120. Four photosystem I monomers, organized in a dimer of dimer, form two distinct interfaces that are largely mediated by specifically orientated polar lipids, such as sulfoquinovosyl diacylglycerol. The structure depicts a more closely connected network of chlorophylls across monomer interfaces than those seen in trimeric PSI from thermophilic cyanobacteria, possibly allowing a more efficient energy transfer between monomers. Our physiological data also revealed a functional link of photosystem I oligomerization to cyclic electron flow and thylakoid membrane organization.
| + | |
| | | | |
| - | Structural and functional insights into the tetrameric photosystem I from heterocyst-forming cyanobacteria.,Zheng L, Li Y, Li X, Zhong Q, Li N, Zhang K, Zhang Y, Chu H, Ma C, Li G, Zhao J, Gao N Nat Plants. 2019 Oct;5(10):1087-1097. doi: 10.1038/s41477-019-0525-6. Epub 2019, Oct 8. PMID:31595062<ref>PMID:31595062</ref>
| + | ==See Also== |
| - | | + | *[[Photosystem I 3D structures|Photosystem I 3D structures]] |
| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
| + | |
| - | </div>
| + | |
| - | <div class="pdbe-citations 6k61" style="background-color:#fffaf0;"></div>
| + | |
| - | == References ==
| + | |
| - | <references/>
| + | |
| | __TOC__ | | __TOC__ |
| - | </StructureSection> | + | </SX> |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Nostoc sp. pcc 7120]] | + | [[Category: Nostoc sp. PCC 7120 = FACHB-418]] |
| - | [[Category: Photosystem I]]
| + | [[Category: Chu H]] |
| - | [[Category: Chu, H]] | + | [[Category: Gao N]] |
| - | [[Category: Gao, N]] | + | [[Category: Li G]] |
| - | [[Category: Li, G]] | + | [[Category: Li N]] |
| - | [[Category: Li, N]] | + | [[Category: Li X]] |
| - | [[Category: Li, X]] | + | [[Category: Li Y]] |
| - | [[Category: Li, Y]] | + | [[Category: Ma C]] |
| - | [[Category: Ma, C]] | + | [[Category: Zhang K]] |
| - | [[Category: Zhang, K]] | + | [[Category: Zhang Y]] |
| - | [[Category: Zhang, Y]] | + | [[Category: Zhao J]] |
| - | [[Category: Zhao, J]] | + | [[Category: Zheng L]] |
| - | [[Category: Zheng, L]] | + | [[Category: Zhong Q]] |
| - | [[Category: Zhong, Q]] | + | |
| - | [[Category: Pcc7120]]
| + | |
| - | [[Category: Photosynthesis]]
| + | |
| - | [[Category: Photosystem i]]
| + | |
| - | [[Category: PSI, Protein structure initiative]]
| + | |
