+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-24107 | |||||||||
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Title | Cryo-EM structure of TACAN in the apo form (TMEM120A) | |||||||||
Map data | ||||||||||
Sample |
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Function / homology | Function and homology information protein heterooligomerization / nuclear inner membrane / fat cell differentiation / detection of mechanical stimulus involved in sensory perception of pain / monoatomic ion transmembrane transport / protein homooligomerization / monoatomic ion channel activity / membrane / plasma membrane Similarity search - Function | |||||||||
Biological species | Mus musculus (house mouse) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 3.5 Å | |||||||||
Authors | Niu Y / Tao X / MacKinnon R | |||||||||
Funding support | United States, 1 items
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Citation | Journal: Elife / Year: 2021 Title: Analysis of the mechanosensor channel functionality of TACAN. Authors: Yiming Niu / Xiao Tao / George Vaisey / Paul Dominic B Olinares / Hanan Alwaseem / Brian T Chait / Roderick MacKinnon / Abstract: Mechanosensitive ion channels mediate transmembrane ion currents activated by mechanical forces. A mechanosensitive ion channel called TACAN was recently reported. We began to study TACAN with the ...Mechanosensitive ion channels mediate transmembrane ion currents activated by mechanical forces. A mechanosensitive ion channel called TACAN was recently reported. We began to study TACAN with the intent to understand how it senses mechanical forces and functions as an ion channel. Using cellular patch-recording methods, we failed to identify mechanosensitive ion channel activity. Using membrane reconstitution methods, we found that TACAN, at high protein concentrations, produces heterogeneous conduction levels that are not mechanosensitive and are most consistent with disruptions of the lipid bilayer. We determined the structure of TACAN using single-particle cryo-electron microscopy and observed that it is a symmetrical dimeric transmembrane protein. Each protomer contains an intracellular-facing cleft with a coenzyme A cofactor, confirmed by mass spectrometry. The TACAN protomer is related in three-dimensional structure to a fatty acid elongase, ELOVL7. Whilst its physiological function remains unclear, we anticipate that TACAN is not a mechanosensitive ion channel. | |||||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | EM map: SurfViewMolmilJmol/JSmol |
Supplemental images |
-Downloads & links
-EMDB archive
Map data | emd_24107.map.gz | 59.7 MB | EMDB map data format | |
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Header (meta data) | emd-24107-v30.xml emd-24107.xml | 12.3 KB 12.3 KB | Display Display | EMDB header |
Images | emd_24107.png | 101.5 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-24107 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-24107 | HTTPS FTP |
-Related structure data
Related structure data | 7n0kMC 7n0lC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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-Map
File | Download / File: emd_24107.map.gz / Format: CCP4 / Size: 64 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Voxel size | X=Y=Z: 1.03 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
-Sample components
-Entire : Homo-dimeric assembly of wild type TACAN(TMEM120A)
Entire | Name: Homo-dimeric assembly of wild type TACAN(TMEM120A) |
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Components |
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-Supramolecule #1: Homo-dimeric assembly of wild type TACAN(TMEM120A)
Supramolecule | Name: Homo-dimeric assembly of wild type TACAN(TMEM120A) / type: complex / ID: 1 / Parent: 0 / Macromolecule list: all |
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Source (natural) | Organism: Mus musculus (house mouse) |
Recombinant expression | Organism: Homo sapiens (human) |
-Macromolecule #1: Ion channel TACAN
Macromolecule | Name: Ion channel TACAN / type: protein_or_peptide / ID: 1 / Number of copies: 2 / Enantiomer: LEVO |
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Source (natural) | Organism: Mus musculus (house mouse) |
Molecular weight | Theoretical: 40.797297 KDa |
Recombinant expression | Organism: Homo sapiens (human) |
Sequence | String: MQSPPPDPLG DCLRNWEDLQ QDFQGIQETH RLYRLKLEEL TKLQANCTNS ITRQKKRLQE LALVLKKCRP SLPSESMEAA QELENQMKE RQGLFFDMEA YLPKKNGLYL SLVLGNVNVT LLSKQAKFAY KDEYEKFKLY LTIILIVISF TCRFLLNSRV T DAAFNFLL ...String: MQSPPPDPLG DCLRNWEDLQ QDFQGIQETH RLYRLKLEEL TKLQANCTNS ITRQKKRLQE LALVLKKCRP SLPSESMEAA QELENQMKE RQGLFFDMEA YLPKKNGLYL SLVLGNVNVT LLSKQAKFAY KDEYEKFKLY LTIILIVISF TCRFLLNSRV T DAAFNFLL VWYYCTLTIR ESILINNGSR IKGWWVFHHY VSTFLSGVML TWPDGLMYQK FRNQFLSFSM YQSFVQFLQY YY QSGCLYR LRALGERHTM DLTVEGFQSW MWRGLTFLLP FLFFGHFWQL FNALTLFNLA RDPECKEWQV LMCGFPFLLL FLG NFFTTL RVVHQKFHSQ QHGNKKD |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 6 mg/mL |
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Buffer | pH: 7.4 Details: 20 mM HEPES pH 7.4, 250 mM NaCl, and 0.06% Digitonin (w/v) |
Grid | Model: Quantifoil R1.2/1.3 / Material: GOLD / Mesh: 400 / Support film - Material: CARBON / Support film - topology: HOLEY / Pretreatment - Type: GLOW DISCHARGE |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 95 % / Chamber temperature: 298 K / Instrument: FEI VITROBOT MARK IV |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | C2 aperture diameter: 100.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: DARK FIELD |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
Image recording | Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Number grids imaged: 1 / Average exposure time: 10.0 sec. / Average electron dose: 75.4 e/Å2 |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
CTF correction | Software - Name: Gctf (ver. 1.0.6) |
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Initial angle assignment | Type: MAXIMUM LIKELIHOOD Software: (Name: RELION (ver. 3.0), RELION (ver. 3.1), cryoSPARC (ver. 2.9.0)) |
Final 3D classification | Number classes: 4 / Software - Name: RELION (ver. 3.1) |
Final angle assignment | Type: MAXIMUM LIKELIHOOD / Software - Name: RELION (ver. 3.1) |
Final reconstruction | Applied symmetry - Point group: C2 (2 fold cyclic) / Resolution.type: BY AUTHOR / Resolution: 3.5 Å / Resolution method: FSC 0.143 CUT-OFF / Software - Name: cryoSPARC (ver. 2.9.0) / Number images used: 110090 |