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Open data
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Basic information
| Entry | Database: EMDB / ID: EMD-25169 | |||||||||
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| Title | TWIK1 in MSP1E3D1 Lipid Nanodisc at pH 5.5 | |||||||||
Map data | TWIK1 in MSP1E3D1 Lipid Nanodisc at pH 5.5 | |||||||||
Sample |
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Keywords | K+ Channel / pH / TRANSPORT PROTEIN | |||||||||
| Function / homology | Function and homology informationTandem of pore domain in a weak inwardly rectifying K+ channels (TWIK) / Phase 4 - resting membrane potential / potassium channel complex / voltage-gated monoatomic ion channel activity involved in regulation of postsynaptic membrane potential / inward rectifier potassium channel complex / ligand-gated channel activity / potassium ion leak channel activity / regulation of resting membrane potential / inward rectifier potassium channel activity / cellular response to acidic pH ...Tandem of pore domain in a weak inwardly rectifying K+ channels (TWIK) / Phase 4 - resting membrane potential / potassium channel complex / voltage-gated monoatomic ion channel activity involved in regulation of postsynaptic membrane potential / inward rectifier potassium channel complex / ligand-gated channel activity / potassium ion leak channel activity / regulation of resting membrane potential / inward rectifier potassium channel activity / cellular response to acidic pH / glutamate secretion / sodium channel activity / potassium channel activity / potassium ion transmembrane transport / sodium ion transmembrane transport / chloride transmembrane transport / synaptic membrane / response to nicotine / brush border membrane / recycling endosome / perikaryon / endosome / apical plasma membrane / protein heterodimerization activity / dendrite / identical protein binding / membrane / plasma membrane Similarity search - Function | |||||||||
| Biological species | ![]() | |||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 3.43 Å | |||||||||
Authors | Turney TS / Brohawn SG | |||||||||
| Funding support | United States, 2 items
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Citation | Journal: Nat Commun / Year: 2022Title: Structural Basis for pH-gating of the K channel TWIK1 at the selectivity filter. Authors: Toby S Turney / Vivian Li / Stephen G Brohawn / ![]() Abstract: TWIK1 (K2P1.1, KCNK1) is a widely expressed pH-gated two-pore domain K channel (K2P) that contributes to cardiac rhythm generation and insulin release from pancreatic beta cells. TWIK1 displays ...TWIK1 (K2P1.1, KCNK1) is a widely expressed pH-gated two-pore domain K channel (K2P) that contributes to cardiac rhythm generation and insulin release from pancreatic beta cells. TWIK1 displays unique properties among K2Ps including low basal activity and inhibition by extracellular protons through incompletely understood mechanisms. Here, we present cryo-EM structures of TWIK1 in lipid nanodiscs at high and low pH that reveal a previously undescribed gating mechanism at the K selectivity filter. At high pH, TWIK1 adopts an open conformation. At low pH, protonation of an extracellular histidine results in a cascade of conformational changes that close the channel by sealing the top of the selectivity filter, displacing the helical cap to block extracellular ion access pathways, and opening gaps for lipid block of the intracellular cavity. These data provide a mechanistic understanding for extracellular pH-gating of TWIK1 and illustrate how diverse mechanisms have evolved to gate the selectivity filter of K channels. #1: Journal: Biorxiv / Year: 2021Title: Structural Basis for pH-Gating of the K + Channel TWIK1 at the Selectivity Filter Authors: Turney TS / Li V / Brohawn SG | |||||||||
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Structure visualization
| Movie |
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| Structure viewer | EM map: SurfView Molmil Jmol/JSmol |
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Downloads & links
-EMDB archive
| Map data | emd_25169.map.gz | 19.9 MB | EMDB map data format | |
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| Header (meta data) | emd-25169-v30.xml emd-25169.xml | 17.9 KB 17.9 KB | Display Display | EMDB header |
| FSC (resolution estimation) | emd_25169_fsc.xml | 7.2 KB | Display | FSC data file |
| Images | emd_25169.png | 41.8 KB | ||
| Masks | emd_25169_msk_1.map | 30.5 MB | Mask map | |
| Filedesc metadata | emd-25169.cif.gz | 5.9 KB | ||
| Others | emd_25169_half_map_1.map.gz emd_25169_half_map_2.map.gz | 22.4 MB 22.5 MB | ||
| Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-25169 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-25169 | HTTPS FTP |
-Validation report
| Summary document | emd_25169_validation.pdf.gz | 760.5 KB | Display | EMDB validaton report |
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| Full document | emd_25169_full_validation.pdf.gz | 760 KB | Display | |
| Data in XML | emd_25169_validation.xml.gz | 12.7 KB | Display | |
| Data in CIF | emd_25169_validation.cif.gz | 17.6 KB | Display | |
| Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-25169 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-25169 | HTTPS FTP |
-Related structure data
| Related structure data | ![]() 7sk1MC ![]() 7sk0C M: atomic model generated by this map C: citing same article ( |
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| Similar structure data |
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Links
| EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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| Related items in Molecule of the Month |
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Map
| File | Download / File: emd_25169.map.gz / Format: CCP4 / Size: 30.5 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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| Annotation | TWIK1 in MSP1E3D1 Lipid Nanodisc at pH 5.5 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Voxel size | X=Y=Z: 1.115 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Density |
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| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Details | EMDB XML:
CCP4 map header:
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-Supplemental data
-Mask #1
| File | emd_25169_msk_1.map | ||||||||||||
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-Half map: Half Map 1
| File | emd_25169_half_map_1.map | ||||||||||||
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| Annotation | Half Map 1 | ||||||||||||
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-Half map: Half Map 2
| File | emd_25169_half_map_2.map | ||||||||||||
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| Annotation | Half Map 2 | ||||||||||||
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Sample components
-Entire : TWIK1 in MSPE3D1 Lipid Nanodisc at pH 5.5
| Entire | Name: TWIK1 in MSPE3D1 Lipid Nanodisc at pH 5.5 |
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| Components |
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-Supramolecule #1: TWIK1 in MSPE3D1 Lipid Nanodisc at pH 5.5
| Supramolecule | Name: TWIK1 in MSPE3D1 Lipid Nanodisc at pH 5.5 / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1 |
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| Source (natural) | Organism: ![]() |
-Macromolecule #1: Potassium channel subfamily K member 1
| Macromolecule | Name: Potassium channel subfamily K member 1 / type: protein_or_peptide / ID: 1 / Number of copies: 2 / Enantiomer: LEVO |
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| Source (natural) | Organism: ![]() |
| Molecular weight | Theoretical: 38.265984 KDa |
| Recombinant expression | Organism: Komagataella pastoris (fungus) |
| Sequence | String: MLQSLAGSSC VRLVERHRSA WCFGFLVLGY LLYLVFGAVV FSSVELPYED LLRQELRKLK RRFLEEHECL SEPQLEQFLG RVLEASNYG VSVLSNASGN WNWDFTSALF FASTVLSTTG YGHTVPLSDG GKAFCIIYSV IGIPFTLLFL TAVVQRVTVH V TRRPVLYF ...String: MLQSLAGSSC VRLVERHRSA WCFGFLVLGY LLYLVFGAVV FSSVELPYED LLRQELRKLK RRFLEEHECL SEPQLEQFLG RVLEASNYG VSVLSNASGN WNWDFTSALF FASTVLSTTG YGHTVPLSDG GKAFCIIYSV IGIPFTLLFL TAVVQRVTVH V TRRPVLYF HIRWGFSKQV VAIVHAVLLG FVTVSCFFFI PAAVFSVLED DWNFLESFYF CFISLSTIGL GDYVPGEGYN QK FRELYKI GITCYLLLGL IAMLVVLETF CELHELKKFR KMFYVKKDKD EDQVHIMEHD QLSFSSITEQ AAGLKEEQKQ NEP FVASQS PPYEDGSANH UniProtKB: Potassium channel subfamily K member 1 |
-Macromolecule #2: POTASSIUM ION
| Macromolecule | Name: POTASSIUM ION / type: ligand / ID: 2 / Number of copies: 3 / Formula: K |
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| Molecular weight | Theoretical: 39.098 Da |
-Macromolecule #3: N-OCTANE
| Macromolecule | Name: N-OCTANE / type: ligand / ID: 3 / Number of copies: 2 / Formula: OCT |
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| Molecular weight | Theoretical: 114.229 Da |
| Chemical component information | ![]() ChemComp-OCT: |
-Macromolecule #4: TETRADECANE
| Macromolecule | Name: TETRADECANE / type: ligand / ID: 4 / Number of copies: 2 / Formula: C14 |
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| Molecular weight | Theoretical: 198.388 Da |
| Chemical component information | ![]() ChemComp-C14: |
-Experimental details
-Structure determination
| Method | cryo EM |
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Processing | single particle reconstruction |
| Aggregation state | particle |
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Sample preparation
| Buffer | pH: 5.5 Component:
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| Grid | Model: Quantifoil R1.2/1.3 | ||||||||||||
| Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K / Instrument: FEI VITROBOT MARK III |
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Electron microscopy
| Microscope | FEI TALOS ARCTICA |
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| Image recording | Film or detector model: GATAN K3 (6k x 4k) / Average electron dose: 50.3523 e/Å2 |
| Electron beam | Acceleration voltage: 200 kV / Electron source: FIELD EMISSION GUN |
| Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD |
| Experimental equipment | ![]() Model: Talos Arctica / Image courtesy: FEI Company |
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About Yorodumi



Keywords
Authors
United States, 2 items
Citation
UCSF Chimera













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Y (Row.)
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Komagataella pastoris (fungus)

Processing


