+ Open data
Open data
- Basic information
Basic information
| Entry |  | |||||||||
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| Title | Structure of Xenopus KCNQ1-CaM | |||||||||
|  Map data | ||||||||||
|  Sample | 
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|  Keywords | ion channel / TRANSPORT PROTEIN | |||||||||
| Function / homology |  Function and homology information regulation of gastric acid secretion / membrane repolarization / delayed rectifier potassium channel activity / outward rectifier potassium channel activity / CaM pathway / Cam-PDE 1 activation / intestinal absorption / 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 / CaM pathway / Cam-PDE 1 activation / intestinal absorption / 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 / CaMK IV-mediated phosphorylation of CREB / PKA activation / negative regulation of high voltage-gated calcium channel activity / Glycogen breakdown (glycogenolysis) / CLEC7A (Dectin-1) induces NFAT activation / Activation of RAC1 downstream of NMDARs / negative regulation of ryanodine-sensitive calcium-release channel activity / organelle localization by membrane tethering / mitochondrion-endoplasmic reticulum membrane tethering / autophagosome membrane docking / negative regulation of calcium ion export across plasma membrane / regulation of cardiac muscle cell action potential / renal absorption / presynaptic endocytosis / Synthesis of IP3 and IP4 in the cytosol / regulation of cell communication by electrical coupling involved in cardiac conduction / Phase 0 - rapid depolarisation / calcineurin-mediated signaling / Negative regulation of NMDA receptor-mediated neuronal transmission / Unblocking of NMDA receptors, glutamate binding and activation / inner ear development / RHO GTPases activate PAKs / Ion transport by P-type ATPases / Uptake and function of anthrax toxins / regulation of ryanodine-sensitive calcium-release channel activity / protein phosphatase activator activity / Long-term potentiation / Calcineurin activates NFAT / Regulation of MECP2 expression and activity / DARPP-32 events / voltage-gated potassium channel activity / catalytic complex / Smooth Muscle Contraction / monoatomic ion channel complex / detection of calcium ion / regulation of cardiac muscle contraction / RHO GTPases activate IQGAPs / regulation of cardiac muscle contraction by regulation of the release of sequestered calcium ion / cellular response to interferon-beta / Protein methylation / calcium channel inhibitor activity / Activation of AMPK downstream of NMDARs / presynaptic cytosol / Ion homeostasis / regulation of release of sequestered calcium ion into cytosol by sarcoplasmic reticulum / eNOS activation / titin binding / Tetrahydrobiopterin (BH4) synthesis, recycling, salvage and regulation / sperm midpiece / regulation of calcium-mediated signaling / phosphatidylinositol-4,5-bisphosphate binding / voltage-gated potassium channel complex / potassium ion transmembrane transport / calcium channel complex / FCERI mediated Ca+2 mobilization / substantia nigra development / Ras activation upon Ca2+ influx through NMDA receptor / regulation of heart rate / FCGR3A-mediated IL10 synthesis / cytoplasmic vesicle membrane / Antigen activates B Cell Receptor (BCR) leading to generation of second messengers / calyx of Held / adenylate cyclase activator activity / sarcomere / VEGFR2 mediated cell proliferation / protein serine/threonine kinase activator activity / VEGFR2 mediated vascular permeability / regulation of cytokinesis / spindle microtubule / calcium channel regulator activity / positive regulation of receptor signaling pathway via JAK-STAT / Translocation of SLC2A4 (GLUT4) to the plasma membrane / RAF activation / Transcriptional activation of mitochondrial biogenesis / response to calcium ion / cellular response to type II interferon / Stimuli-sensing channels / G2/M transition of mitotic cell cycle / long-term synaptic potentiation / spindle pole / RAS processing / Signaling by RAF1 mutants / calcium-dependent protein binding / Signaling by moderate kinase activity BRAF mutants / Paradoxical activation of RAF signaling by kinase inactive BRAF / Signaling downstream of RAS mutants Similarity search - Function | |||||||||
| Biological species |  Xenopus laevis (African clawed frog) /  Homo sapiens (human) | |||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 3.84 Å | |||||||||
|  Authors | Willegems K / Kyriakis E | |||||||||
| Funding support |  Canada, 1 items 
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|  Citation |  Journal: Nat Commun / Year: 2022 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 visualization
| Supplemental images | 
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- Downloads & links
Downloads & links
-EMDB archive
| Map data |  emd_25816.map.gz | 162.1 MB |  EMDB map data format | |
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| Header (meta data) |  emd-25816-v30.xml  emd-25816.xml | 17.3 KB 17.3 KB | Display Display |  EMDB header | 
| FSC (resolution estimation) |  emd_25816_fsc.xml | 17.4 KB | Display |  FSC data file | 
| Images |  emd_25816.png | 82.1 KB | ||
| Filedesc metadata |  emd-25816.cif.gz | 6.6 KB | ||
| Archive directory |  http://ftp.pdbj.org/pub/emdb/structures/EMD-25816  ftp://ftp.pdbj.org/pub/emdb/structures/EMD-25816 | HTTPS FTP | 
-Validation report
| Summary document |  emd_25816_validation.pdf.gz | 508.5 KB | Display |  EMDB validaton report | 
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| Full document |  emd_25816_full_validation.pdf.gz | 508.1 KB | Display | |
| Data in XML |  emd_25816_validation.xml.gz | 13.6 KB | Display | |
| Data in CIF |  emd_25816_validation.cif.gz | 18.3 KB | Display | |
| Arichive directory |  https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-25816  ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-25816 | HTTPS FTP | 
-Related structure data
| Related structure data |  7tcpMC  7tciC C: citing same article ( M: atomic model generated by this map | 
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| Similar structure data | Similarity search - Function & homology  F&H Search | 
- Links
Links
| EMDB pages |  EMDB (EBI/PDBe) /  EMDataResource | 
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| Related items in Molecule of the Month | 
- Map
Map
| File |  Download / File: emd_25816.map.gz / Format: CCP4 / Size: 209.3 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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| Projections & slices | Image control
 
 Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
| Voxel size | X=Y=Z: 0.73 Å | ||||||||||||||||||||||||||||||||||||
| Density | 
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| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
| Details | EMDB XML: 
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-Supplemental data
- Sample components
Sample components
-Entire : Potassium voltage-gated channel subfamily KQT member 1 in complex...
| Entire | Name: Potassium voltage-gated channel subfamily KQT member 1 in complex with calmodulin | 
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| Components | 
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-Supramolecule #1: Potassium voltage-gated channel subfamily KQT member 1 in complex...
| Supramolecule | Name: Potassium voltage-gated channel subfamily KQT member 1 in complex with calmodulin type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1-#2 | 
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| Source (natural) | Organism:  Xenopus laevis (African clawed frog) | 
| Molecular weight | Theoretical: 317.56 KDa | 
-Macromolecule #1: Potassium voltage-gated channel subfamily KQT member 1
| Macromolecule | Name: Potassium voltage-gated channel subfamily KQT member 1 type: protein_or_peptide / ID: 1 / Number of copies: 4 / Enantiomer: LEVO | 
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| Source (natural) | Organism:  Xenopus laevis (African clawed frog) | 
| Molecular weight | Theoretical: 62.663398 KDa | 
| Recombinant expression | Organism:  Homo sapiens (human) | 
| Sequence | String: MATDPPRPTI NLDPRVSIYS GRRPLLSRTN IQGRVYNFLE RPTGWKCFVY HFTVFLIVLI CLIFSVLSTI QQYNNLATET  LFWMEIVLV VFFGAEYVVR LWSAGCRSKY VGVWGRLRFA RKPISVIDLI VVVASVIVLC VGSNGQVFAT SAIRGIRFLQ I LRMLHVDR  ...String: MATDPPRPTI NLDPRVSIYS GRRPLLSRTN IQGRVYNFLE RPTGWKCFVY HFTVFLIVLI CLIFSVLSTI QQYNNLATET  LFWMEIVLV VFFGAEYVVR LWSAGCRSKY VGVWGRLRFA RKPISVIDLI VVVASVIVLC VGSNGQVFAT SAIRGIRFLQ I LRMLHVDR QGGTWRLLGS VVFIHRQELI TTLYIGFLGL IFSSYFVYLA EKDAIDSSGE YQFGSYADAL WWGVVTVTTI GY GDKVPQT WIGKTIASCF SVFAISFFAL PAGILGSGFA LKVQQKQRQK HFNRQIPAAA SLIQTAWRCY AAENPDSATW KIY IRKQSR NHHLMSPSPK PKKSAMVKKK KIRTERDEGS TDKMLNIPHI TYDHVADDRK NDGYSVESYE NTVRKPFGFL DPST GPFIR TSSFTDDLDM EGDTLLTPIT HISELKEHHR AAIKVIRRMQ YFVAKKKFQQ ARKPYDVRDV IEQYSQGHLN LMVRI KELQ RRLDQSLGKP SLFLSVSDKV KDKGINTIGS RLNRVEDKVT QMDHKLNLIT DMLHHLLTNQ QSNS UniProtKB: Potassium voltage-gated channel subfamily KQT member 1 | 
-Macromolecule #2: Calmodulin-1
| Macromolecule | Name: Calmodulin-1 / type: protein_or_peptide / ID: 2 / Number of copies: 4 / Enantiomer: LEVO | 
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| Source (natural) | Organism:  Homo sapiens (human) | 
| Molecular weight | Theoretical: 16.852545 KDa | 
| Recombinant expression | Organism:  Homo sapiens (human) | 
| Sequence | String: MADQLTEEQI AEFKEAFSLF DKDGDGTITT KELGTVMRSL GQNPTEAELQ DMINEVDADG NGTIDFPEFL TMMARKMKDT  DSEEEIREA FRVFDKDGNG YISAAELRHV MTNLGEKLTD EEVDEMIREA DIDGDGQVNY EEFVQMMTAK UniProtKB: Calmodulin-1 | 
-Macromolecule #3: CALCIUM ION
| Macromolecule | Name: CALCIUM ION / type: ligand / ID: 3 / Number of copies: 12 / Formula: CA | 
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| Molecular weight | Theoretical: 40.078 Da | 
-Experimental details
-Structure determination
| Method | cryo EM | 
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|  Processing | single particle reconstruction | 
| Aggregation state | particle | 
- Sample preparation
Sample preparation
| Concentration | 2 mg/mL | |||||||||||||||||||||
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| Buffer | pH: 7.2 Component: 
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| Grid | Model: Quantifoil R1.2/1.3 / Material: COPPER / Mesh: 400 / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 25 sec. | |||||||||||||||||||||
| Vitrification | Cryogen name: ETHANE / Chamber humidity: 98 % / Chamber temperature: 277.15 K / Instrument: FEI VITROBOT MARK IV | 
- Electron microscopy
Electron microscopy
| Microscope | FEI TITAN KRIOS | 
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| Image recording | Film or detector model: FEI FALCON IV (4k x 4k) / Detector mode: COUNTING / Number grids imaged: 1 / Number real images: 19997 / Average electron dose: 50.0 e/Å2 | 
| Electron beam | Acceleration voltage: 300 kV / Electron source:  FIELD EMISSION GUN | 
| Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 4.9 µm / Nominal defocus min: 0.36 µm | 
| Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN | 
| Experimental equipment |  Model: Titan Krios / Image courtesy: FEI Company | 
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