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Open data
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Basic information
Entry | Database: PDB / ID: 7sk0 | |||||||||
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Title | TWIK1 in MSP1D1 lipid nanodisc at pH 7.4 | |||||||||
![]() | Potassium channel subfamily K member 1 | |||||||||
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Function / homology | ![]() Tandem of pore domain in a weak inwardly rectifying K+ channels (TWIK) / Phase 4 - resting membrane potential / ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Similarity search - Function | |||||||||
Biological species | ![]() ![]() ![]() | |||||||||
Method | ![]() ![]() ![]() | |||||||||
![]() | Turney, T.S. / Brohawn, S.G. | |||||||||
Funding support | ![]()
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![]() | ![]() Title: 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: ![]() Title: Structural Basis for pH-Gating of the K + Channel TWIK1 at the Selectivity Filter Authors: Turney, T.S. / Li, V. / Brohawn, S.G. | |||||||||
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Structure visualization
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 101 KB | Display | ![]() |
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PDB format | ![]() | 78.7 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 25168MC ![]() 7sk1C M: map data used to model this data C: citing same article ( |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 38265.984 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() ![]() #2: Chemical | ![]() #3: Chemical | ChemComp-K / Has ligand of interest | Y | |
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-Experimental details
-Experiment
Experiment | Method: ![]() |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: ![]() |
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Sample preparation
Component | Name: TWIK1 in MSP1D1 Lipid Nanodisc at pH 7.4 / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT | ||||||||||||||||||||
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Source (natural) | Organism: ![]() ![]() ![]() | ||||||||||||||||||||
Source (recombinant) | Organism: ![]() ![]() | ||||||||||||||||||||
Buffer solution | pH: 7.4 | ||||||||||||||||||||
Buffer component |
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Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied![]() ![]() | ||||||||||||||||||||
Specimen support | Grid type: Quantifoil R1.2/1.3 | ||||||||||||||||||||
Vitrification![]() | Instrument: FEI VITROBOT MARK III / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Talos Arctica / Image courtesy: FEI Company |
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Microscopy | Model: FEI TALOS ARCTICA |
Electron gun | Electron source![]() ![]() |
Electron lens | Mode: BRIGHT FIELD![]() |
Image recording | Electron dose: 49.715 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
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Processing
Software | Name: PHENIX / Version: 1.18.2_3874: / 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: 2872868 | ||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry![]() ![]() | ||||||||||||||||||||||||||||||||||||
3D reconstruction![]() | Resolution: 3.33 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 92438 / Symmetry type: POINT | ||||||||||||||||||||||||||||||||||||
Atomic model building | B value: 147.12 / Space: REAL / Target criteria: Correlation coefficient | ||||||||||||||||||||||||||||||||||||
Atomic model building | PDB-ID: 3UKM | ||||||||||||||||||||||||||||||||||||
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