View source for 1pxs


==Structure of Met56Ala mutant of Bacteriorhodopsin==
<StructureSection load='1pxs' size='340' side='right'caption='[[1pxs]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1pxs]] is a 2 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=1PXS OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1PXS 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=RET:RETINAL'>RET</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=1pxs FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1pxs OCA], [https://pdbe.org/1pxs PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1pxs RCSB], [https://www.ebi.ac.uk/pdbsum/1pxs PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1pxs 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/px/1pxs_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=1pxs ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The molecular forces that stabilize membrane protein structure are poorly understood. To investigate these forces we introduced alanine substitutions at 24 positions in the B helix of bacteriorhodopsin and examined their effects on structure and stability. Although most of the results can be rationalized in terms of the folded structure, there are a number of surprises. (1) We find a remarkably high frequency of stabilizing mutations (17%), indicating that membrane proteins are not highly optimized for stability. (2) Helix B is kinked, with the kink centered around Pro50. The P50A mutation has no effect on stability, however, and a crystal structure reveals that the helix remains bent, indicating that tertiary contacts dominate in the distortion of this helix. (3) We find that the protein is stabilized by about 1kcal/mol for every 38A(2) of surface area buried, which is quite similar to soluble proteins in spite of their dramatically different environments. (4) We find little energetic difference, on average, in the burial of apolar surface or polar surface area, implying that van der Waals packing is the dominant force that drives membrane protein folding.

Side-chain contributions to membrane protein structure and stability.,Faham S, Yang D, Bare E, Yohannan S, Whitelegge JP, Bowie JU J Mol Biol. 2004 Jan 2;335(1):297-305. PMID:14659758<ref>PMID:14659758</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1pxs" style="background-color:#fffaf0;"></div>

==See Also==
*[[Bacteriorhodopsin 3D structures|Bacteriorhodopsin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Halobacterium salinarum]]
[[Category: Large Structures]]
[[Category: Bare E]]
[[Category: Bowie JU]]
[[Category: Faham S]]
[[Category: Whitelegge JP]]
[[Category: Yang D]]
[[Category: Yohannan S]]