5g3a: Difference between revisions
New page: '''Unreleased structure''' The entry 5g3a is ON HOLD Authors: Bommer, M., Bondar, A.N., Zouni, A., Dobbek, H., Dau, H. Description: PsbO subunit of Photosystem II, beta barrel domain a... |
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==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=''> | |||
== Structural highlights == | |||
<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='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='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'>[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> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/PSBO_SYNEL PSBO_SYNEL] | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
In 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<ref>PMID:27454911</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
[[Category: | <div class="pdbe-citations 5g3a" style="background-color:#fffaf0;"></div> | ||
[[Category: | |||
[[Category: Bondar | ==See Also== | ||
[[Category: | *[[Photosystem II 3D structures|Photosystem II 3D structures]] | ||
[[Category: | == References == | ||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Thermosynechococcus vestitus BP-1]] | |||
[[Category: Bommer M]] | |||
[[Category: Bondar AN]] | |||
[[Category: Dau H]] | |||
[[Category: Dobbek H]] | |||
[[Category: Zouni A]] | |||