+Open data
-Basic information
Entry | Database: PDB / ID: 8ehw | ||||||
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Title | cryo-EM structure of TMEM63A in nanodisc | ||||||
Components | CSC1-like protein 1 | ||||||
Keywords | MEMBRANE PROTEIN / ion channel / mechanosensitive / monomeric | ||||||
Function / homology | Function and homology information surfactant secretion / osmolarity-sensing monoatomic cation channel activity / mechanosensitive monoatomic ion channel activity / calcium-activated cation channel activity / tertiary granule membrane / centriolar satellite / specific granule membrane / early endosome membrane / nucleic acid binding / lysosomal membrane ...surfactant secretion / osmolarity-sensing monoatomic cation channel activity / mechanosensitive monoatomic ion channel activity / calcium-activated cation channel activity / tertiary granule membrane / centriolar satellite / specific granule membrane / early endosome membrane / nucleic acid binding / lysosomal membrane / intracellular membrane-bounded organelle / Neutrophil degranulation / extracellular exosome / plasma membrane Similarity search - Function | ||||||
Biological species | Homo sapiens (human) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.8 Å | ||||||
Authors | Zheng, W. / Fu, T.M. / Holt, J.R. | ||||||
Funding support | United States, 1items
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Citation | Journal: Neuron / Year: 2023 Title: TMEM63 proteins function as monomeric high-threshold mechanosensitive ion channels. Authors: Wang Zheng / Shaun Rawson / Zhangfei Shen / Elakkiya Tamilselvan / Harper E Smith / Julia Halford / Chen Shen / Swetha E Murthy / Maximilian H Ulbrich / Marcos Sotomayor / Tian-Min Fu / Jeffrey R Holt / Abstract: OSCA/TMEM63s form mechanically activated (MA) ion channels in plants and animals, respectively. OSCAs and related TMEM16s and transmembrane channel-like (TMC) proteins form homodimers with two pores. ...OSCA/TMEM63s form mechanically activated (MA) ion channels in plants and animals, respectively. OSCAs and related TMEM16s and transmembrane channel-like (TMC) proteins form homodimers with two pores. Here, we uncover an unanticipated monomeric configuration of TMEM63 proteins. Structures of TMEM63A and TMEM63B (referred to as TMEM63s) revealed a single highly restricted pore. Functional analyses demonstrated that TMEM63s are bona fide mechanosensitive ion channels, characterized by small conductance and high thresholds. TMEM63s possess evolutionary variations in the intracellular linker IL2, which mediates dimerization in OSCAs. Replacement of OSCA1.2 IL2 with TMEM63A IL2 or mutations to key variable residues resulted in monomeric OSCA1.2 and MA currents with significantly higher thresholds. Structural analyses revealed substantial conformational differences in the mechano-sensing domain IL2 and gating helix TM6 between TMEM63s and OSCA1.2. Our studies reveal that mechanosensitivity in OSCA/TMEM63 channels is affected by oligomerization and suggest gating mechanisms that may be shared by OSCA/TMEM63, TMEM16, and TMC channels. | ||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8ehw.cif.gz | 127.2 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8ehw.ent.gz | 96.5 KB | Display | PDB format |
PDBx/mmJSON format | 8ehw.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8ehw_validation.pdf.gz | 1.1 MB | Display | wwPDB validaton report |
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Full document | 8ehw_full_validation.pdf.gz | 1.1 MB | Display | |
Data in XML | 8ehw_validation.xml.gz | 31.1 KB | Display | |
Data in CIF | 8ehw_validation.cif.gz | 43.3 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/eh/8ehw ftp://data.pdbj.org/pub/pdb/validation_reports/eh/8ehw | HTTPS FTP |
-Related structure data
Related structure data | 28153MC 8ehxC M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 93200.992 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Homo sapiens (human) / Gene: TMEM63A, KIAA0489, KIAA0792 / Cell line (production host): expi293 / Production host: Homo sapiens (human) / References: UniProt: O94886 |
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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 |
-Sample preparation
Component | Name: TMEM63A purified protein in nanodisc / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT | |||||||||||||||
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Molecular weight | Value: 0.11 MDa / Experimental value: YES | |||||||||||||||
Source (natural) | Organism: Homo sapiens (human) | |||||||||||||||
Source (recombinant) | Organism: Homo sapiens (human) | |||||||||||||||
Buffer solution | pH: 7.4 | |||||||||||||||
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: GOLD / Grid mesh size: 400 divisions/in. / Grid type: Quantifoil R1.2/1.3 | |||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 279.15 K |
-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: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Nominal magnification: 105000 X / Nominal defocus max: 2000 nm / Nominal defocus min: 1000 nm / Cs: 2.7 mm / C2 aperture diameter: 50 µm / Alignment procedure: COMA FREE |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER |
Image recording | Average exposure time: 2.497 sec. / Electron dose: 50.7 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
EM imaging optics | Energyfilter slit width: 20 eV |
-Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||||||
Symmetry | Point symmetry: C1 (asymmetric) | ||||||||||||||||||||||||||||
3D reconstruction | Resolution: 3.8 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 64399 / Algorithm: BACK PROJECTION / Symmetry type: POINT | ||||||||||||||||||||||||||||
Atomic model building | Protocol: AB INITIO MODEL / Space: REAL |