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Open data
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Basic information
Entry | Database: PDB / ID: 7tcp | ||||||
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Title | Structure of Xenopus KCNQ1-CaM | ||||||
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![]() | TRANSPORT PROTEIN / ion channel | ||||||
Function / homology | ![]() regulation of gastric acid secretion / membrane repolarization / delayed rectifier potassium channel activity / outward rectifier potassium channel activity / intestinal absorption / CaM pathway / Cam-PDE 1 activation / Sodium/Calcium exchangers / Calmodulin induced events / Reduction of cytosolic Ca++ levels ...regulation of gastric acid secretion / membrane repolarization / delayed rectifier potassium channel activity / outward rectifier potassium channel activity / intestinal absorption / CaM pathway / Cam-PDE 1 activation / Sodium/Calcium exchangers / Calmodulin induced events / Reduction of cytosolic Ca++ levels / Activation of Ca-permeable Kainate Receptor / CREB1 phosphorylation through the activation of CaMKII/CaMKK/CaMKIV cascasde / Loss of phosphorylation of MECP2 at T308 / CREB1 phosphorylation through the activation of Adenylate Cyclase / PKA activation / negative regulation of high voltage-gated calcium channel activity / CaMK IV-mediated phosphorylation of CREB / Glycogen breakdown (glycogenolysis) / organelle localization by membrane tethering / negative regulation of calcium ion export across plasma membrane / CLEC7A (Dectin-1) induces NFAT activation / Activation of RAC1 downstream of NMDARs / mitochondrion-endoplasmic reticulum membrane tethering / autophagosome membrane docking / presynaptic endocytosis / renal absorption / regulation of cardiac muscle cell action potential / negative regulation of peptidyl-threonine phosphorylation / calcineurin-mediated signaling / positive regulation of ryanodine-sensitive calcium-release channel activity / regulation of cell communication by electrical coupling involved in cardiac conduction / Synthesis of IP3 and IP4 in the cytosol / negative regulation of ryanodine-sensitive calcium-release channel activity / Phase 0 - rapid depolarisation / Negative regulation of NMDA receptor-mediated neuronal transmission / monoatomic ion channel complex / Unblocking of NMDA receptors, glutamate binding and activation / RHO GTPases activate PAKs / Ion transport by P-type ATPases / inner ear development / Uptake and function of anthrax toxins / protein phosphatase activator activity / Long-term potentiation / Regulation of MECP2 expression and activity / Calcineurin activates NFAT / regulation of ryanodine-sensitive calcium-release channel activity / DARPP-32 events / voltage-gated potassium channel activity / catalytic complex / Smooth Muscle Contraction / regulation of cardiac muscle contraction / detection of calcium ion / RHO GTPases activate IQGAPs / calcium channel inhibitor activity / regulation of cardiac muscle contraction by regulation of the release of sequestered calcium ion / presynaptic cytosol / cellular response to interferon-beta / Protein methylation / Activation of AMPK downstream of NMDARs / positive regulation of protein autophosphorylation / regulation of release of sequestered calcium ion into cytosol by sarcoplasmic reticulum / Ion homeostasis / eNOS activation / regulation of calcium-mediated signaling / titin binding / Tetrahydrobiopterin (BH4) synthesis, recycling, salvage and regulation / voltage-gated potassium channel complex / sperm midpiece / calcium channel complex / phosphatidylinositol-4,5-bisphosphate binding / substantia nigra development / positive regulation of peptidyl-threonine phosphorylation / calyx of Held / cytoplasmic vesicle membrane / FCERI mediated Ca+2 mobilization / adenylate cyclase activator activity / Ras activation upon Ca2+ influx through NMDA receptor / FCGR3A-mediated IL10 synthesis / regulation of heart rate / sarcomere / protein serine/threonine kinase activator activity / Antigen activates B Cell Receptor (BCR) leading to generation of second messengers / regulation of cytokinesis / VEGFR2 mediated cell proliferation / VEGFR2 mediated vascular permeability / Translocation of SLC2A4 (GLUT4) to the plasma membrane / positive regulation of protein serine/threonine kinase activity / spindle microtubule / positive regulation of receptor signaling pathway via JAK-STAT / RAF activation / Transcriptional activation of mitochondrial biogenesis / Stimuli-sensing channels / cellular response to type II interferon / spindle pole / response to calcium ion / calcium-dependent protein binding / RAS processing / Signaling by RAF1 mutants / Signaling by moderate kinase activity BRAF mutants / Paradoxical activation of RAF signaling by kinase inactive BRAF Similarity search - Function | ||||||
Biological species | ![]() ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.84 Å | ||||||
![]() | Willegems, K. / Kyriakis, E. / Van Petegem, F. / Eldstrom, J. / Fedida, D. | ||||||
Funding support | ![]()
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![]() | ![]() Title: Structural and electrophysiological basis for the modulation of KCNQ1 channel currents by ML277. Authors: Katrien Willegems / Jodene Eldstrom / Efthimios Kyriakis / Fariba Ataei / Harutyun Sahakyan / Ying Dou / Sophia Russo / Filip Van Petegem / David Fedida / ![]() ![]() Abstract: The KCNQ1 ion channel plays critical physiological roles in electrical excitability and K recycling in organs including the heart, brain, and gut. Loss of function is relatively common and can cause ...The KCNQ1 ion channel plays critical physiological roles in electrical excitability and K recycling in organs including the heart, brain, and gut. Loss of function is relatively common and can cause sudden arrhythmic death, sudden infant death, epilepsy and deafness. Here, we report cryogenic electron microscopic (cryo-EM) structures of Xenopus KCNQ1 bound to Ca/Calmodulin, with and without the KCNQ1 channel activator, ML277. A single binding site for ML277 was identified, localized to a pocket lined by the S4-S5 linker, S5 and S6 helices of two separate subunits. Several pocket residues are not conserved in other KCNQ isoforms, explaining specificity. MD simulations and point mutations support this binding location for ML277 in open and closed channels and reveal that prevention of inactivation is an important component of the activator effect. Our work provides direction for therapeutic intervention targeting KCNQ1 loss of function pathologies including long QT interval syndrome and seizures. | ||||||
History |
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 342.3 KB | Display | ![]() |
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PDB format | ![]() | 272.3 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Summary document | ![]() | 888.8 KB | Display | ![]() |
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Full document | ![]() | 897.9 KB | Display | |
Data in XML | ![]() | 55.8 KB | Display | |
Data in CIF | ![]() | 86.1 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 25816MC ![]() 7tciC M: map data used to model this data C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 62663.398 Da / Num. of mol.: 4 / Fragment: UNP residues 67-610 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() #2: Protein | Mass: 16852.545 Da / Num. of mol.: 4 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() #3: Chemical | ChemComp-CA / Has ligand of interest | N | |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
Component | Name: Potassium voltage-gated channel subfamily KQT member 1 in complex with calmodulin Type: COMPLEX / Entity ID: #1-#2 / Source: MULTIPLE SOURCES | |||||||||||||||||||||||||||||||||||
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Molecular weight | Value: 0.31756 MDa / Experimental value: NO | |||||||||||||||||||||||||||||||||||
Source (natural) | Organism: ![]() | |||||||||||||||||||||||||||||||||||
Source (recombinant) | Organism: ![]() | |||||||||||||||||||||||||||||||||||
Buffer solution | pH: 7.2 | |||||||||||||||||||||||||||||||||||
Buffer component |
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Specimen | Conc.: 2 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES | |||||||||||||||||||||||||||||||||||
Specimen support | Grid material: COPPER / Grid mesh size: 400 divisions/in. / Grid type: Quantifoil R1.2/1.3 | |||||||||||||||||||||||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 98 % / Chamber temperature: 277.15 K |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 4900 nm / Nominal defocus min: 360 nm |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Electron dose: 50 e/Å2 / Detector mode: COUNTING / Film or detector model: FEI FALCON IV (4k x 4k) / Num. of grids imaged: 1 / Num. of real images: 19997 |
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Processing
Software | Name: PHENIX / Version: 1.19.2_4158: / Classification: refinement | ||||||||||||||||||||||||
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EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
Particle selection | Num. of particles selected: 1830000 | ||||||||||||||||||||||||
Symmetry | Point symmetry: C4 (4 fold cyclic) | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.84 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 71241 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
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