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Open data
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Basic information
Entry | Database: EMDB / ID: EMD-24691 | |||||||||
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Title | Cryo-EM structure of a TTYH3 cis-dimer | |||||||||
![]() | TTYH3 cis-dimer | |||||||||
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Function / homology | ![]() volume-sensitive chloride channel activity / intracellularly calcium-gated chloride channel activity / Stimuli-sensing channels / chloride transport / chloride channel activity / chloride channel complex / membrane => GO:0016020 / plasma membrane Similarity search - Function | |||||||||
Biological species | ![]() ![]() | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 3.23 Å | |||||||||
![]() | Li B / Brohawn SG / Hoel CM | |||||||||
Funding support | ![]()
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![]() | ![]() 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 |
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Structure viewer | EM map: ![]() ![]() ![]() |
Supplemental images |
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Downloads & links
-EMDB archive
Map data | ![]() | 203.4 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 11.8 KB 11.8 KB | Display Display | ![]() |
Images | ![]() | 66.4 KB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 7rtwMC ![]() 7rttC ![]() 7rtuC ![]() 7rtvC M: atomic model generated by this map C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
EM raw data | ![]() Data #1: Unaligned multi-frame micrographs of ttyh3 in cisdimer [micrographs - multiframe]) |
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Links
EMDB pages | ![]() ![]() |
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Map
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Annotation | TTYH3 cis-dimer | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.137 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
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Sample components
-Entire : TTYH2 with Ca2+
Entire | Name: TTYH2 with Ca2+ |
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Components |
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-Supramolecule #1: TTYH2 with Ca2+
Supramolecule | Name: TTYH2 with Ca2+ / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1 |
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Source (natural) | Organism: ![]() ![]() |
Recombinant expression | Organism: Mammalia (mammals) |
-Macromolecule #1: Protein tweety homolog 3
Macromolecule | Name: Protein tweety homolog 3 / type: protein_or_peptide / ID: 1 / Number of copies: 2 / Enantiomer: LEVO |
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Source (natural) | Organism: ![]() ![]() |
Molecular weight | Theoretical: 58.077863 KDa |
Recombinant expression | Organism: Mammalia (mammals) |
Sequence | String: GPAGVSYAAP WWVSLLHRLP HFDLRWEATS SQFRPEDADY QQALLLLGAT ALACLALDLL FLLFYSFWLC CRRRKTDEHL DADCCCTAW CVIITTLVCS AGIAVGFYGN GETSDGIHRA TYSLRHANRT VAGVQDRVWD TAAALNRTAE PNLQSLERQL A GRQEPLRA ...String: GPAGVSYAAP WWVSLLHRLP HFDLRWEATS SQFRPEDADY QQALLLLGAT ALACLALDLL FLLFYSFWLC CRRRKTDEHL DADCCCTAW CVIITTLVCS AGIAVGFYGN GETSDGIHRA TYSLRHANRT VAGVQDRVWD TAAALNRTAE PNLQSLERQL A GRQEPLRA VQRLQTLLGT LLGYTAAIPF WRNPGVSLEV LAEQVDLYDW YRWLGYLGLL LLDVIICLLV LVGLIRSSKG IL VGVCLLG VLALVISWGA LGLELAVSVG SSDFCVDPDT FVTKMVEEHS VLSGDILQYY LACSPRATNP FQQKLSGSHK ALV EMQDVV AELLRNVPRE HPATKDPLLR VQEVLNGTEV NLQHLTALVD CRSLHLDYVQ ALTGFCYDGV EGLIYLALFS FVTA LMFSS IVCSIPHTWQ QKRGPDDDGE EETAPGPRQA HDSLYRVHMP SLYSCGSSYG SEASIPAAAH TVSNAPVTEY MSQNA NFQN PRCENTPLIG RESPPPSYTS SMRAKYLATS QPRPDSSGSG HSNS |
-Macromolecule #4: 2-acetamido-2-deoxy-beta-D-glucopyranose
Macromolecule | Name: 2-acetamido-2-deoxy-beta-D-glucopyranose / type: ligand / ID: 4 / Number of copies: 1 / Formula: NAG |
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Molecular weight | Theoretical: 221.208 Da |
Chemical component information | ![]() ChemComp-NAG: |
-Macromolecule #5: CALCIUM ION
Macromolecule | Name: CALCIUM ION / type: ligand / ID: 5 / Number of copies: 2 / Formula: CA |
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Molecular weight | Theoretical: 40.078 Da |
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | single particle reconstruction |
Aggregation state | particle |
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Sample preparation
Concentration | 1.1 mg/mL |
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Buffer | pH: 8 / Details: 20 mM Tris pH 8.0, 150 mM NaCl, 1 mM CaCl2 |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K / Instrument: FEI VITROBOT MARK IV |
Details | This sample was monodisperse |
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Electron microscopy
Microscope | FEI TECNAI ARCTICA |
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Image recording | Film or detector model: GATAN K3 (6k x 4k) / Average electron dose: 1.0038 e/Å2 |
Electron beam | Acceleration voltage: 200 kV / Electron source: ![]() |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: OTHER |
Experimental equipment | ![]() Model: Talos Arctica / Image courtesy: FEI Company |
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Image processing
-Atomic model buiding 1
Refinement | Space: REAL / Protocol: RIGID BODY FIT |
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Output model | ![]() PDB-7rtw: |