View source for 5j9p


==KcsA in vitro==
<StructureSection load='5j9p' size='340' side='right'caption='[[5j9p]], [[Resolution|resolution]] 2.85&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5j9p]] 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=5J9P OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5J9P 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]] 2.85&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</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=5j9p FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5j9p OCA], [https://pdbe.org/5j9p PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5j9p RCSB], [https://www.ebi.ac.uk/pdbsum/5j9p PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5j9p 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> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Cell free protein synthesis (CFPS) has emerged as a promising methodology for protein expression. While polypeptide production is very reliable and efficient using CFPS, the correct cotranslational folding of membrane proteins during CFPS is still a challenge. In this contribution, we describe a two-step protocol in which the integral membrane protein is initially expressed by CFPS as a precipitate followed by an in vitro folding procedure using lipid vesicles for converting the protein precipitate to the correctly folded protein. We demonstrate the feasibility of using this approach for the K+ channels KcsA and MVP and the amino acid transporter LeuT. We determine the crystal structure of the KcsA channel obtained by CFPS and in vitro folding to show the structural similarity to the cellular expressed KcsA channel and to establish the feasibility of using this two-step approach for membrane protein production for structural studies. Our studies show that the correct folding of these membrane proteins with complex topologies can take place in vitro without the involvement of the cellular machinery for membrane protein biogenesis. This indicates that the folding instructions for these complex membrane proteins are contained entirely within the protein sequence.

Combining in Vitro Folding with Cell Free Protein Synthesis for Membrane Protein Expression.,Focke PJ, Hein C, Hoffmann B, Matulef K, Bernhard F, Dotsch V, Valiyaveetil FI Biochemistry. 2016 Jul 21. PMID:27384110<ref>PMID:27384110</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5j9p" style="background-color:#fffaf0;"></div>

==See Also==
*[[Potassium channel 3D structures|Potassium channel 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Streptomyces lividans]]
[[Category: Matulef K]]
[[Category: Valiyaveetil FI]]