View source for 2zzl


==Structure of bacteriorhodopsin's M intermediate at pH 7==
<StructureSection load='2zzl' size='340' side='right'caption='[[2zzl]], [[Resolution|resolution]] 2.03&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2zzl]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Halobacterium_salinarum Halobacterium salinarum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2ZZL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ZZL 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]] 2.03&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=L1P:3-PHOSPHORYL-[1,2-DI-PHYTANYL]GLYCEROL'>L1P</scene>, <scene name='pdbligand=L2P:2,3-DI-PHYTANYL-GLYCEROL'>L2P</scene>, <scene name='pdbligand=L3P:2,3-DI-O-PHYTANLY-3-SN-GLYCERO-1-PHOSPHORYL-3-SN-GLYCEROL-1-PHOSPHATE'>L3P</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=RET:RETINAL'>RET</scene>, <scene name='pdbligand=SGA:O3-SULFONYLGALACTOSE'>SGA</scene>, <scene name='pdbligand=SOG:2-HYDROXYMETHYL-6-OCTYLSULFANYL-TETRAHYDRO-PYRAN-3,4,5-TRIOL'>SOG</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=2zzl FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2zzl OCA], [https://pdbe.org/2zzl PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2zzl RCSB], [https://www.ebi.ac.uk/pdbsum/2zzl PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2zzl ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BACR_HALSA BACR_HALSA] Light-driven proton pump.
== 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/zz/2zzl_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=2zzl ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The hexagonal P622 crystal of bacteriorhodopsin, which is made up of stacked membranes, is stable provided that the precipitant concentration in the soaking solution is higher than a critical value (i.e., 1.5 M ammonium sulfate). Diffraction data showed that the crystal lattice shrank linearly with increasing precipitant concentration, due primarily to narrowing of intermembrane spaces. Although the crystal shrinkage did not affect the rate of formation of the photoreaction M intermediate, its lifetime increased exponentially with the precipitant concentration. It was suggested that the energetic barrier of the M-to-N transition becomes higher when the motional freedom of the EF loop is reduced by crystal lattice force. As a result of this property, the M state accumulated predominantly when the crystal that was soaked at a high precipitant concentration was illuminated at room temperature. Structural data obtained at various pH levels showed that the overall structure of M is not strongly dependent on pH, except that Glu194 and Glu204 in the proton release complex are more separated at pH 7 than at pH 4.4. This result suggests that light-induced disruption of the paired structure of Glu194 and Glu204 is incomplete when external pH is lower than the pK(a) value of the proton release group in the M state.

Crystal structures of different substrates of bacteriorhodopsin's M intermediate at various pH levels.,Yamamoto M, Hayakawa N, Murakami M, Kouyama T J Mol Biol. 2009 Oct 30;393(3):559-73. Epub 2009 Aug 25. PMID:19712684<ref>PMID:19712684</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2zzl" style="background-color:#fffaf0;"></div>

==See Also==
*[[Bacteriorhodopsin 3D structures|Bacteriorhodopsin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Halobacterium salinarum]]
[[Category: Large Structures]]
[[Category: Kouyama T]]
[[Category: Yamamoto M]]