6fl9: Difference between revisions
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The | ==The active form of a pentameric ion channel (sTeLIC) gated by alkaline pH - Wild type 2.3 Angstrom resolution== | ||
<StructureSection load='6fl9' size='340' side='right'caption='[[6fl9]], [[Resolution|resolution]] 2.30Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[6fl9]] is a 5 chain structure with sequence from [https://en.wikipedia.org/wiki/Endosymbiont_of_Tevnia_jerichonana_(vent_Tica) Endosymbiont of Tevnia jerichonana (vent Tica)]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6FL9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6FL9 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]] 2.3Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BNG:B-NONYLGLUCOSIDE'>BNG</scene>, <scene name='pdbligand=PG4:TETRAETHYLENE+GLYCOL'>PG4</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=6fl9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6fl9 OCA], [https://pdbe.org/6fl9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6fl9 RCSB], [https://www.ebi.ac.uk/pdbsum/6fl9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6fl9 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/G2FID1_9GAMM G2FID1_9GAMM] | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Pentameric ligand-gated ion channels (pLGICs) constitute a widespread class of ion channels, present in archaea, bacteria, and eukaryotes. Upon binding of their agonists in the extracellular domain, the transmembrane pore opens, allowing ions to go through, via a gating mechanism that can be modulated by a number of drugs. Even though high-resolution structural information on pLGICs has increased in a spectacular way in recent years, both in bacterial and in eukaryotic systems, the structure of the open channel conformation of some intensively studied receptors whose structures are known in a nonactive (closed) form, such as Erwinia chrysanthemi pLGIC (ELIC), is still lacking. Here we describe a gammaproteobacterial pLGIC from an endo-symbiont of Tevnia jerichonana (sTeLIC), whose sequence is closely related to the pLGIC from ELIC with 28% identity. We provide an X-ray crystallographic structure at 2.3 A in an active conformation, where the pore is found to be more open than any current conformation found for pLGICs. In addition, two charged restriction rings are present in the vestibule. Functional characterization shows sTeLIC to be a cationic channel activated at alkaline pH. It is inhibited by divalent cations, but not by quaternary ammonium ions, such as tetramethylammonium. Additionally, we found that sTeLIC is allosterically potentiated by aromatic amino acids Phe and Trp, as well as their derivatives, such as 4-bromo-cinnamate, whose cocrystal structure reveals a vestibular binding site equivalent to, but more deeply buried than, the one already described for benzodiazepines in ELIC. | |||
Crystal structures of a pentameric ion channel gated by alkaline pH show a widely open pore and identify a cavity for modulation.,Hu H, Nemecz A, Van Renterghem C, Fourati Z, Sauguet L, Corringer PJ, Delarue M Proc Natl Acad Sci U S A. 2018 Apr 24;115(17):E3959-E3968. doi:, 10.1073/pnas.1717700115. Epub 2018 Apr 9. PMID:29632192<ref>PMID:29632192</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
[[Category: Delarue | <div class="pdbe-citations 6fl9" style="background-color:#fffaf0;"></div> | ||
[[Category: Hu | |||
==See Also== | |||
*[[Ion channels 3D structures|Ion channels 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Delarue M]] | |||
[[Category: Hu H]] | |||
Latest revision as of 15:29, 9 May 2024
The active form of a pentameric ion channel (sTeLIC) gated by alkaline pH - Wild type 2.3 Angstrom resolutionThe active form of a pentameric ion channel (sTeLIC) gated by alkaline pH - Wild type 2.3 Angstrom resolution
Structural highlights
FunctionPublication Abstract from PubMedPentameric ligand-gated ion channels (pLGICs) constitute a widespread class of ion channels, present in archaea, bacteria, and eukaryotes. Upon binding of their agonists in the extracellular domain, the transmembrane pore opens, allowing ions to go through, via a gating mechanism that can be modulated by a number of drugs. Even though high-resolution structural information on pLGICs has increased in a spectacular way in recent years, both in bacterial and in eukaryotic systems, the structure of the open channel conformation of some intensively studied receptors whose structures are known in a nonactive (closed) form, such as Erwinia chrysanthemi pLGIC (ELIC), is still lacking. Here we describe a gammaproteobacterial pLGIC from an endo-symbiont of Tevnia jerichonana (sTeLIC), whose sequence is closely related to the pLGIC from ELIC with 28% identity. We provide an X-ray crystallographic structure at 2.3 A in an active conformation, where the pore is found to be more open than any current conformation found for pLGICs. In addition, two charged restriction rings are present in the vestibule. Functional characterization shows sTeLIC to be a cationic channel activated at alkaline pH. It is inhibited by divalent cations, but not by quaternary ammonium ions, such as tetramethylammonium. Additionally, we found that sTeLIC is allosterically potentiated by aromatic amino acids Phe and Trp, as well as their derivatives, such as 4-bromo-cinnamate, whose cocrystal structure reveals a vestibular binding site equivalent to, but more deeply buried than, the one already described for benzodiazepines in ELIC. Crystal structures of a pentameric ion channel gated by alkaline pH show a widely open pore and identify a cavity for modulation.,Hu H, Nemecz A, Van Renterghem C, Fourati Z, Sauguet L, Corringer PJ, Delarue M Proc Natl Acad Sci U S A. 2018 Apr 24;115(17):E3959-E3968. doi:, 10.1073/pnas.1717700115. Epub 2018 Apr 9. PMID:29632192[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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