View source for 4ctd


==X-ray structure of an engineered OmpG loop6-deletion==
<StructureSection load='4ctd' size='340' side='right'caption='[[4ctd]], [[Resolution|resolution]] 3.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4ctd]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4CTD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4CTD 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]] 3.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=C8E:(HYDROXYETHYLOXY)TRI(ETHYLOXY)OCTANE'>C8E</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</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=4ctd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ctd OCA], [https://pdbe.org/4ctd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ctd RCSB], [https://www.ebi.ac.uk/pdbsum/4ctd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ctd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/OMPG_ECOLI OMPG_ECOLI] Forms channels functionally larger than those of classical porins.<ref>PMID:11758943</ref>   May act as a regulator of the RCS-phosphorelay signal transduction pathway.<ref>PMID:11758943</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Porins, like outer membrane protein G (OmpG) of Escherichia coli, are ideal templates among ion channels for protein and chemical engineering because of their robustness and simple architecture. OmpG shows fast transitions between open and closed states, which were attributed to loop 6 (L6). As flickering limits single-channel-based applications, we pruned L6 by either 8 or 12 amino acids. While the open probabilities of both L6 variants resemble that of native OmpG, their gating frequencies were reduced by 63 and 81%, respectively. Using the 3.2 A structure of the shorter L6 variant in the open state, we engineered a minimal porin (220 amino acids), where all remaining extramembranous loops were truncated. Unexpectedly, this minimized porin still exhibited gating, but it was 5-fold less frequent than in OmpG. The residual gating of the minimal pore is hence independent of L6 rearrangements and involves narrowing of the ion conductance pathway most probably driven by global stretching-flexing deformations of the membrane-embedded beta-barrel.

Structure-based engineering of a minimal porin reveals loop-independent channel closure.,Grosse W, Psakis G, Mertins B, Reiss P, Windisch D, Brademann F, Burck J, Ulrich A, Koert U, Essen LO Biochemistry. 2014 Jul 29;53(29):4826-38. doi: 10.1021/bi500660q. Epub 2014 Jul, 15. PMID:24988371<ref>PMID:24988371</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4ctd" style="background-color:#fffaf0;"></div>

==See Also==
*[[Porin 3D structures|Porin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Essen L-O]]
[[Category: Grosse W]]