View source for 2hvk


==crystal structure of the KcsA-Fab-TBA complex in high K+==
<StructureSection load='2hvk' size='340' side='right'caption='[[2hvk]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2hvk]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus] and [https://en.wikipedia.org/wiki/Streptomyces_lividans Streptomyces lividans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2HVK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2HVK 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]] 1.9&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=F09:NONAN-1-OL'>F09</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=L2C:(2S)-3-HYDROXY-2-(NONANOYLOXY)PROPYL+LAURATE'>L2C</scene>, <scene name='pdbligand=TBA:TETRABUTYLAMMONIUM+ION'>TBA</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=2hvk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2hvk OCA], [https://pdbe.org/2hvk PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2hvk RCSB], [https://www.ebi.ac.uk/pdbsum/2hvk PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2hvk ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/KCSA_STRLI KCSA_STRLI] Acts as a pH-gated potassium ion channel; changing the cytosolic pH from 7 to 4 opens the channel, although it is not clear if this is the physiological stimulus for channel opening. Monovalent cation preference is K(+) > Rb(+) > NH4(+) >> Na(+) > Li(+).<ref>PMID:7489706</ref> 
== 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/hv/2hvk_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=2hvk ConSurf].
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== Publication Abstract from PubMed ==
K(+) channels play essential roles in regulating membrane excitability of many diverse cell types by selectively conducting K(+) ions through their pores. Many diverse molecules can plug the pore and modulate the K(+) current. Quaternary ammonium (QA) ions are a class of pore blockers that have been used for decades by biophysicists to probe the pore, leading to important insights into the structure-function relation of K(+) channels. However, many key aspects of the QA-blocking mechanisms remain unclear to date, and understanding these questions requires high resolution structural information. Here, we address the question of whether intracellular QA blockade causes conformational changes of the K(+) channel selectivity filter. We have solved the structures of the KcsA K(+) channel in complex with tetrabutylammonium (TBA) and tetrabutylantimony (TBSb) under various ionic conditions. Our results demonstrate that binding of TBA or TBSb causes no significant change in the KcsA structure at high concentrations of permeant ions. We did observe the expected conformational change of the filter at low concentration of K(+), but this change appears to be independent of TBA or TBSb blockade.

Crystallographic study of the tetrabutylammonium block to the KcsA K+ channel.,Yohannan S, Hu Y, Zhou Y J Mol Biol. 2007 Feb 23;366(3):806-14. Epub 2006 Dec 2. PMID:17196615<ref>PMID:17196615</ref>

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

==See Also==
*[[Monoclonal Antibodies 3D structures|Monoclonal Antibodies 3D structures]]
*[[Potassium channel 3D structures|Potassium channel 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Streptomyces lividans]]
[[Category: Zhou Y]]