View source for 7tkt


==SthK closed state, cAMP-bound in the presence of detergent==
<StructureSection load='7tkt' size='340' side='right'caption='[[7tkt]], [[Resolution|resolution]] 3.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7tkt]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Spirochaeta_thermophila_DSM_6578 Spirochaeta thermophila DSM 6578]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7TKT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7TKT FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CMP:ADENOSINE-3,5-CYCLIC-MONOPHOSPHATE'>CMP</scene>, <scene name='pdbligand=PGW:(1R)-2-{[(S)-{[(2S)-2,3-DIHYDROXYPROPYL]OXY}(HYDROXY)PHOSPHORYL]OXY}-1-[(HEXADECANOYLOXY)METHYL]ETHYL+(9Z)-OCTADEC-9-ENOATE'>PGW</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=7tkt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7tkt OCA], [https://pdbe.org/7tkt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7tkt RCSB], [https://www.ebi.ac.uk/pdbsum/7tkt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7tkt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/G0GA88_SPITZ G0GA88_SPITZ] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Lipids play important roles in regulating membrane protein function, but the molecular mechanisms used are elusive. Here we investigated how anionic lipids modulate SthK, a bacterial pacemaker channel homolog, and HCN2, whose activity contributes to pacemaking in the heart and brain. Using SthK allowed the reconstitution of purified channels in controlled lipid compositions for functional and structural assays that are not available for the eukaryotic channels. We identified anionic lipids bound tightly to SthK and their exact binding locations and determined that they potentiate channel activity. Cryo-EM structures in the most potentiating lipids revealed an open state and identified a nonannular lipid bound with its headgroup near an intersubunit salt bridge that clamps the intracellular channel gate shut. Breaking this conserved salt bridge abolished lipid modulation in SthK and eukaryotic HCN2 channels, indicating that anionic membrane lipids facilitate channel opening by destabilizing these interactions. Our findings underline the importance of state-dependent protein-lipid interactions.

Anionic lipids unlock the gates of select ion channels in the pacemaker family.,Schmidpeter PAM, Wu D, Rheinberger J, Riegelhaupt PM, Tang H, Robinson CV, Nimigean CM Nat Struct Mol Biol. 2022 Nov;29(11):1092-1100. doi: 10.1038/s41594-022-00851-2. , Epub 2022 Nov 9. PMID:36352139<ref>PMID:36352139</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7tkt" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Spirochaeta thermophila DSM 6578]]
[[Category: Nimigean CM]]
[[Category: Rheinberger J]]
[[Category: Schmidpeter PA]]