+Open data
-Basic information
Entry | Database: PDB / ID: 7rtw | ||||||
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Title | Cryo-EM structure of a TTYH3 cis-dimer | ||||||
Components | Protein tweety homolog 3 | ||||||
Keywords | MEMBRANE PROTEIN / TTYH2 / momomer | ||||||
Function / homology | Function and homology information volume-sensitive chloride channel activity / L-glutamate transmembrane transport / intracellularly calcium-gated chloride channel activity / Stimuli-sensing channels / chloride channel activity / chloride channel complex / calcium ion binding / membrane / plasma membrane Similarity search - Function | ||||||
Biological species | Mus musculus (house mouse) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.23 Å | ||||||
Authors | Li, B. / Brohawn, S.G. / Hoel, C.M. | ||||||
Funding support | United States, 1items
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Citation | Journal: Nat Commun / Year: 2021 Title: Structures of tweety homolog proteins TTYH2 and TTYH3 reveal a Ca-dependent switch from intra- to intermembrane dimerization. Authors: Baobin Li / Christopher M Hoel / Stephen G Brohawn / Abstract: Tweety homologs (TTYHs) comprise a conserved family of transmembrane proteins found in eukaryotes with three members (TTYH1-3) in vertebrates. They are widely expressed in mammals including at high ...Tweety homologs (TTYHs) comprise a conserved family of transmembrane proteins found in eukaryotes with three members (TTYH1-3) in vertebrates. They are widely expressed in mammals including at high levels in the nervous system and have been implicated in cancers and other diseases including epilepsy, chronic pain, and viral infections. TTYHs have been reported to form Ca- and cell volume-regulated anion channels structurally distinct from any characterized protein family with potential roles in cell adhesion, migration, and developmental signaling. To provide insight into TTYH family structure and function, we determined cryo-EM structures of Mus musculus TTYH2 and TTYH3 in lipid nanodiscs. TTYH2 and TTYH3 adopt a previously unobserved fold which includes an extended extracellular domain with a partially solvent exposed pocket that may be an interaction site for hydrophobic molecules. In the presence of Ca, TTYH2 and TTYH3 form homomeric cis-dimers bridged by extracellularly coordinated Ca. Strikingly, in the absence of Ca, TTYH2 forms trans-dimers that span opposing membranes across a ~130 Å intermembrane space as well as a monomeric state. All TTYH structures lack ion conducting pathways and we do not observe TTYH2-dependent channel activity in cells. We conclude TTYHs are not pore forming subunits of anion channels and their function may involve Ca-dependent changes in quaternary structure, interactions with hydrophobic molecules near the extracellular membrane surface, and/or association with additional protein partners. | ||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | Molecule: MolmilJmol/JSmol |
-Downloads & links
-Download
PDBx/mmCIF format | 7rtw.cif.gz | 139.2 KB | Display | PDBx/mmCIF format |
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PDB format | pdb7rtw.ent.gz | 109.6 KB | Display | PDB format |
PDBx/mmJSON format | 7rtw.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 7rtw_validation.pdf.gz | 1 MB | Display | wwPDB validaton report |
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Full document | 7rtw_full_validation.pdf.gz | 1 MB | Display | |
Data in XML | 7rtw_validation.xml.gz | 27.1 KB | Display | |
Data in CIF | 7rtw_validation.cif.gz | 39.1 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/rt/7rtw ftp://data.pdbj.org/pub/pdb/validation_reports/rt/7rtw | HTTPS FTP |
-Related structure data
Related structure data | 24691MC 7rttC 7rtuC 7rtvC M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | |
EM raw data | EMPIAR-10850 (Title: Cryo-EM structure of a cis-dimer TTYH3 / Data size: 2.1 TB Data #1: Unaligned multi-frame micrographs of ttyh3 in cisdimer [micrographs - multiframe]) |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 58077.863 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Mus musculus (house mouse) / Gene: Ttyh3, Kiaa1691 / Production host: Mammalia (mammals) / References: UniProt: Q6P5F7 #2: Polysaccharide | beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta- ...beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose Source method: isolated from a genetically manipulated source #3: Polysaccharide | 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose | Source method: isolated from a genetically manipulated source #4: Sugar | ChemComp-NAG / | #5: Chemical | 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 |
-Sample preparation
Component | Name: TTYH2 with Ca2+ / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Molecular weight | Units: MEGADALTONS / Experimental value: NO |
Source (natural) | Organism: Mus musculus (house mouse) |
Source (recombinant) | Organism: Mammalia (mammals) |
Buffer solution | pH: 8 / Details: 20 mM Tris pH 8.0, 150 mM NaCl, 1 mM CaCl2 |
Specimen | Conc.: 1.1 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES / Details: This sample was monodisperse |
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277 K |
-Electron microscopy imaging
Experimental equipment | Model: Talos Arctica / Image courtesy: FEI Company |
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Microscopy | Model: FEI TECNAI ARCTICA |
Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 200 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: OTHER |
Image recording | Electron dose: 1.0038 e/Å2 / Film or detector model: GATAN K3 (6k x 4k) |
-Processing
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EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.23 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 96285 / Symmetry type: POINT | ||||||||||||||||||||||||
Atomic model building | Protocol: RIGID BODY FIT / Space: REAL | ||||||||||||||||||||||||
Refinement | Cross valid method: NONE Stereochemistry target values: GeoStd + Monomer Library + CDL v1.2 | ||||||||||||||||||||||||
Displacement parameters | Biso mean: 54.15 Å2 | ||||||||||||||||||||||||
Refine LS restraints |
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