View source for 2i20


==Bacteriorhodopsin/lipid complex, M state of D96A mutant==
<StructureSection load='2i20' size='340' side='right'caption='[[2i20]], [[Resolution|resolution]] 2.08&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2i20]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"bacillus_halobius_ruber"_klebahn_1919 "bacillus halobius ruber" klebahn 1919]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2I20 OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=2I20 FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=LI1:1-[2,6,10.14-TETRAMETHYL-HEXADECAN-16-YL]-2-[2,10,14-TRIMETHYLHEXADECAN-16-YL]GLYCEROL'>LI1</scene>, <scene name='pdbligand=RET:RETINAL'>RET</scene>, <scene name='pdbligand=SQU:2,10,23-TRIMETHYL-TETRACOSANE'>SQU</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1c8s|1c8s]]</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=2i20 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2i20 OCA], [http://pdbe.org/2i20 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2i20 RCSB], [http://www.ebi.ac.uk/pdbsum/2i20 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2i20 ProSAT]</span></td></tr>
</table>
== Function ==
[[http://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/i2/2i20_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=2i20 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The X-ray diffraction structure of the non-illuminated D96A bacteriorhodopsin mutant reveals structural changes as far away as 15 A from residue 96, at the retinal, Trp-182, Ala-215, and waters 501, 402, and 401. The Asp-to-Ala side-chain replacement breaks its hydrogen bond with Thr-46, and the resulting separation of the cytoplasmic ends of helices B and C is communicated to the retinal region through a chain of covalent and hydrogen bonds. The unexpected long-range consequences of the D96A mutation include breaking the hydrogen bond between O of Ala-215 and water 501 and the formation of a new hydrogen bond between water molecules 401 and 402 in the extracellular region. Because in the T46V mutant a new water molecule appears at Asp-96 and its hydrogen-bond to Ile-45 replaces Thr-46 as its link to helix B, the separation of helices B and C is smaller than that in D96A, and there are no atomic displacements elsewhere in the protein. Propagation of conformational changes along the chain between the retinal and Thr-46 had been observed earlier in the crystal structures of the D96N and E204Q mutants but in the trapped M state. Consistent with the perturbation of the retinal region in D96A, little change of the Thr-46 region occurs between the non-illuminated and M states of this mutant. It appears that a local perturbation can propagate along a track in both directions between the retinal and the Asp-96/Thr-46 pair, either from photoisomerization of the retinal in the wild-type protein in one case or from the D96A mutation in the other.

Propagating structural perturbation inside bacteriorhodopsin: crystal structures of the M state and the D96A and T46V mutants.,Lanyi JK, Schobert B Biochemistry. 2006 Oct 3;45(39):12003-10. PMID:17002299<ref>PMID:17002299</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 2i20" style="background-color:#fffaf0;"></div>

==See Also==
*[[Bacteriorhodopsin 3D structures|Bacteriorhodopsin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus halobius ruber klebahn 1919]]
[[Category: Large Structures]]
[[Category: Lanyi, J K]]
[[Category: Schobert, B]]
[[Category: 7-transmembrane]]
[[Category: Haloarchaea]]
[[Category: Ion pump]]
[[Category: Ion transport]]
[[Category: Lipid]]
[[Category: Membrane protein]]
[[Category: Photoreceptor]]
[[Category: Retinal protein]]
[[Category: Serpentine]]
[[Category: Transport protein]]