5g3a: Difference between revisions
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==PsbO subunit of Photosystem II, beta barrel domain at 100K, pH 10== | ==PsbO subunit of Photosystem II, beta barrel domain at 100K, pH 10== | ||
<StructureSection load='5g3a' size='340' side='right' caption='[[5g3a]], [[Resolution|resolution]] 1.22Å' scene=''> | <StructureSection load='5g3a' size='340' side='right'caption='[[5g3a]], [[Resolution|resolution]] 1.22Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[5g3a]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5G3A OCA]. For a <b>guided tour on the structure components</b> use [ | <table><tr><td colspan='2'>[[5g3a]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermosynechococcus_vestitus_BP-1 Thermosynechococcus vestitus BP-1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5G3A OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5G3A FirstGlance]. <br> | ||
</td></tr><tr id=' | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.224Å</td></tr> | ||
<tr id=' | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=5g3a FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5g3a OCA], [https://pdbe.org/5g3a PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5g3a RCSB], [https://www.ebi.ac.uk/pdbsum/5g3a PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5g3a ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | |||
[https://www.uniprot.org/uniprot/PSBO_SYNEL PSBO_SYNEL] | |||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
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</div> | </div> | ||
<div class="pdbe-citations 5g3a" style="background-color:#fffaf0;"></div> | <div class="pdbe-citations 5g3a" style="background-color:#fffaf0;"></div> | ||
==See Also== | |||
*[[Photosystem II 3D structures|Photosystem II 3D structures]] | |||
== References == | == References == | ||
<references/> | <references/> | ||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: | [[Category: Thermosynechococcus vestitus BP-1]] | ||
[[Category: | [[Category: Bommer M]] | ||
[[Category: | [[Category: Bondar AN]] | ||
[[Category: | [[Category: Dau H]] | ||
[[Category: | [[Category: Dobbek H]] | ||
[[Category: | [[Category: Zouni A]] | ||
Latest revision as of 14:49, 10 January 2024
PsbO subunit of Photosystem II, beta barrel domain at 100K, pH 10PsbO subunit of Photosystem II, beta barrel domain at 100K, pH 10
Structural highlights
FunctionPublication Abstract from PubMedIn all organisms that employ oxygenic photosynthesis, the membrane-extrinsic PsbO protein is a functionally important component of photosystem II. To study the previously proposed proton antenna function of carboxylate clusters at the protein-water interface, we combined crystallography and simulations of a truncated cyanobacterial (Thermosynechococcus elongatus) PsbO without peripheral loops. We expressed the PsbO beta-barrel heterologously and determined crystal structures at resolutions of 1.15-1.5 A at 100 K at various pH values and at 297 K and pH 6. (1) Approximately half of the 177 surface waters identified at 100 K are resolved at 297 K, suggesting significant occupancy of specific water sites at room temperature, and loss of resolvable occupancy for other sites. (2) Within a loop region specific to cyanobacterial PsbO, three residues and four waters coordinating a calcium ion are well ordered even at 297 K; the ligation differs for manganese. (3) The crystal structures show water-carboxylate clusters that could facilitate fast Grotthus-type proton transfer along the protein surface and/or store protons. (4) Two carboxylate side chains, which are part of a structural motif interrupting two beta-strands and connecting PsbO to photosystem II, are within hydrogen bonding distance at pH 6 (100 K). Simulations indicate coupling between protein structure and carboxylate protonation. The crystal structure determined at 100 K and pH 10 indicates broken hydrogen bonding between the carboxylates and local structural change. At pH 6 and 297 K, both conformations were present in the crystal, suggesting conformational dynamics in the functionally relevant pH regime. Taken together, crystallography and molecular dynamics underline a possible mechanism for pH-dependent structural switching. Crystallographic and Computational Analysis of the Barrel Part of the PsbO Protein of Photosystem II: Carboxylate-Water Clusters as Putative Proton Transfer Relays and Structural Switches.,Bommer M, Bondar AN, Zouni A, Dobbek H, Dau H Biochemistry. 2016 Aug 9. PMID:27454911[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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