View source for 3a0b


==Crystal structure of Br-substituted Photosystem II complex==
<StructureSection load='3a0b' size='340' side='right'caption='[[3a0b]], [[Resolution|resolution]] 3.70&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3a0b]] is a 20 chain structure with sequence from [https://en.wikipedia.org/wiki/Thermostichus_vulcanus Thermostichus vulcanus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3A0B OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3A0B 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]] 3.7&#8491;</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=BR:BROMIDE+ION'>BR</scene>, <scene name='pdbligand=CLA:CHLOROPHYLL+A'>CLA</scene>, <scene name='pdbligand=DGD:DIGALACTOSYL+DIACYL+GLYCEROL+(DGDG)'>DGD</scene>, <scene name='pdbligand=FE2:FE+(II)+ION'>FE2</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=LHG:1,2-DIPALMITOYL-PHOSPHATIDYL-GLYCEROLE'>LHG</scene>, <scene name='pdbligand=MGE:(1S)-2-(ALPHA-L-ALLOPYRANOSYLOXY)-1-[(TRIDECANOYLOXY)METHYL]ETHYL+PALMITATE'>MGE</scene>, <scene name='pdbligand=PHO:PHEOPHYTIN+A'>PHO</scene>, <scene name='pdbligand=PQ9:5-[(2E,6E,10E,14E,18E,22E)-3,7,11,15,19,23,27-HEPTAMETHYLOCTACOSA-2,6,10,14,18,22,26-HEPTAENYL]-2,3-DIMETHYLBENZO-1,4-QUINONE'>PQ9</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=3a0b FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3a0b OCA], [https://pdbe.org/3a0b PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3a0b RCSB], [https://www.ebi.ac.uk/pdbsum/3a0b PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3a0b ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PSBA_THEVL PSBA_THEVL] D1 (PsbA) and D2 (PsbD) bind P680, the primary electron donor of photosystem II (PSII) as well as electron acceptors. PSII is a light-driven water plastoquinone oxidoreductase, using light energy to abstract electrons from H(2)O, generating a proton gradient subsequently used for ATP formation.[HAMAP-Rule:MF_01379]
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/a0/3a0b_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=3a0b ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The chloride ion, Cl(-), is an essential cofactor for oxygen evolution of photosystem II (PSII) and is closely associated with the Mn(4)Ca cluster. Its detailed location and function have not been identified, however. We substituted Cl(-) with a bromide ion (Br(-)) or an iodide ion (I(-)) in PSII and analyzed the crystal structures of PSII with Br(-) and I(-) substitutions. Substitution of Cl(-) with Br(-) did not inhibit oxygen evolution, whereas substitution of Cl(-) with I(-) completely inhibited oxygen evolution, indicating the efficient replacement of Cl(-) by I(-). PSII with Br(-) and I(-) substitutions were crystallized, and their structures were analyzed. The results showed that there are 2 anion-binding sites in each PSII monomer; they are located on 2 sides of the Mn(4)Ca cluster at equal distances from the metal cluster. Anion-binding site 1 is close to the main chain of D1-Glu-333, and site 2 is close to the main chain of CP43-Glu-354; these 2 residues are coordinated directly with the Mn(4)Ca cluster. In addition, site 1 is located in the entrance of a proton exit channel. These results indicate that these 2 Cl(-) anions are required to maintain the coordination structure of the Mn(4)Ca cluster as well as the proposed proton channel, thereby keeping the oxygen-evolving complex fully active.

Location of chloride and its possible functions in oxygen-evolving photosystem II revealed by X-ray crystallography.,Kawakami K, Umena Y, Kamiya N, Shen JR Proc Natl Acad Sci U S A. 2009 May 26;106(21):8567-72. Epub 2009 May 11. PMID:19433803<ref>PMID:19433803</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3a0b" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cytochrome C 3D structures|Cytochrome C 3D structures]]
*[[Photosystem II|Photosystem II]]
*[[Photosystem II 3D structures|Photosystem II 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Thermostichus vulcanus]]
[[Category: Kamiya N]]
[[Category: Kawakami K]]
[[Category: Shen J-R]]
[[Category: Umena Y]]