View source for 9vub


==channel C complex with 3==
<StructureSection load='9vub' size='340' side='right'caption='[[9vub]], [[Resolution|resolution]] 3.35&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9vub]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9VUB OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9VUB 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]] 3.35&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=A1B92:N-(4,4-difluorocyclohexyl)-2-(3-methyl-1H-pyrazol-1-yl)-6-(morpholin-4-yl)pyrimidin-4-amine'>A1B92</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CLR:CHOLESTEROL'>CLR</scene>, <scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=POV:(2S)-3-(HEXADECANOYLOXY)-2-[(9Z)-OCTADEC-9-ENOYLOXY]PROPYL+2-(TRIMETHYLAMMONIO)ETHYL+PHOSPHATE'>POV</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=9vub FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9vub OCA], [https://pdbe.org/9vub PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9vub RCSB], [https://www.ebi.ac.uk/pdbsum/9vub PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9vub ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/KCNN2_HUMAN KCNN2_HUMAN] Forms a voltage-independent potassium channel activated by intracellular calcium. Activation is followed by membrane hyperpolarization. Thought to regulate neuronal excitability by contributing to the slow component of synaptic afterhyperpolarization. The channel is blocked by apamin.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The small-conductance calcium-activated potassium (SK1-3 or K(Ca)2) channels regulate the intrinsic excitability and firing frequency of excitable cells. SK channels are modulated by a variety of distinct modulators; however, the underlying mechanisms remain elusive. Here, we present four cryoelectron microscopy structures of the human SK2-calmodulin complex bound with apamin, UCL1684, AP30663, and CAD-1883, elucidating their distinct binding sites and regulatory mechanisms. Apamin and UCL1684 compete for a similar binding site above the selectivity filter, which is formed by the distinct S3-S4 linker of SK2. CAD-1883 glues the N-lobe of calmodulin and the S4-S5 linker of SK2, reinforcing the open state. In contrast, AP30663 resides in the central cavity of SK2, blocking ion conductance. This study reveals multiple modulation sites in SK2 and the molecular mechanisms for the inhibition and potentiation of SK channels, which could advance rational drug design targeting SK2 channel for the treatment of cardiovascular and neurological disorders.

Structural mechanisms for inhibition and activation of human small-conductance Ca(2+)-activated potassium channel SK2.,Ma B, Wu D, Cao E, Chi C, Wang Z, Xia Z, Sun LH, Pan B, Jiang D, Zhang W Nat Commun. 2026 Jan 15;17(1):1770. doi: 10.1038/s41467-026-68475-4. PMID:41540047<ref>PMID:41540047</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9vub" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Jiang DH]]
[[Category: Ma B]]