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Open data
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Basic information
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| Title | Structure of acid-sensing ion channel 5 with calcium | ||||||||||||
Map data | Unsharpened Map | ||||||||||||
Sample |
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Keywords | Ion channel / MEMBRANE PROTEIN / TRANSPORT PROTEIN | ||||||||||||
| Function / homology | Function and homology informationbile acid-gated sodium channel activity / sodium ion import across plasma membrane / proton channel activity / ligand-gated sodium channel activity / neuronal action potential / sodium ion transmembrane transport / Stimuli-sensing channels / apical plasma membrane / plasma membrane Similarity search - Function | ||||||||||||
| Biological species | Homo sapiens (human) | ||||||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 3.0 Å | ||||||||||||
Authors | Freitas MM / Gouaux E | ||||||||||||
| Funding support | United States, 3 items
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Citation | Journal: Nat Commun / Year: 2025Title: The bile acid-sensitive ion channel is gated by Ca-dependent conformational changes in the transmembrane domain. Authors: Makayla M Freitas / Eric Gouaux / ![]() Abstract: The bile acid-sensitive ion channel (BASIC) is the least understood member of the mammalian epithelial Na channel/degenerin (ENaC/DEG) superfamily of ion channels, which are involved in a variety of ...The bile acid-sensitive ion channel (BASIC) is the least understood member of the mammalian epithelial Na channel/degenerin (ENaC/DEG) superfamily of ion channels, which are involved in a variety of physiological processes. While some members of this superfamily, including BASIC, are inhibited by extracellular Ca (Ca), the molecular mechanism underlying Ca modulation remains unclear. Here, by determining the structure of human BASIC (hBASIC) in the presence and absence of Ca using single-particle cryo-electron microscopy (cryo-EM), we reveal Ca-dependent conformational changes in the transmembrane domain and β-linkers. Electrophysiological experiments further show that a glutamate residue in the extracellular vestibule of the pore underpins the Ca-binding site, whose occupancy determines the conformation of the pore and therefore ion flow through the channel. These results reveal the molecular principles governing gating of BASIC and its regulation by Ca ions, demonstrating that Ca ions modulate BASIC function via changes in protein conformation rather than solely from a pore-block, as proposed for other members of this superfamily. | ||||||||||||
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Structure visualization
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Downloads & links
-EMDB archive
| Map data | emd_48342.map.gz | 92.8 MB | EMDB map data format | |
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| Header (meta data) | emd-48342-v30.xml emd-48342.xml | 17.6 KB 17.6 KB | Display Display | EMDB header |
| Images | emd_48342.png | 78.1 KB | ||
| Filedesc metadata | emd-48342.cif.gz | 5.9 KB | ||
| Others | emd_48342_additional_1.map.gz emd_48342_half_map_1.map.gz emd_48342_half_map_2.map.gz | 65.8 MB 122.4 MB 122.4 MB | ||
| Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-48342 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-48342 | HTTPS FTP |
-Validation report
| Summary document | emd_48342_validation.pdf.gz | 826.1 KB | Display | EMDB validaton report |
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| Full document | emd_48342_full_validation.pdf.gz | 825.7 KB | Display | |
| Data in XML | emd_48342_validation.xml.gz | 14.4 KB | Display | |
| Data in CIF | emd_48342_validation.cif.gz | 17.1 KB | Display | |
| Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-48342 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-48342 | HTTPS FTP |
-Related structure data
| Related structure data | ![]() 9mkyMC ![]() 9mkzC ![]() 9mlvC M: atomic model generated by this map C: citing same article ( |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
| EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Map
| File | Download / File: emd_48342.map.gz / Format: CCP4 / Size: 144.7 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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| Annotation | Unsharpened Map | ||||||||||||||||||||||||||||||||||||
| Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
| Voxel size | X=Y=Z: 0.844 Å | ||||||||||||||||||||||||||||||||||||
| Density |
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| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
| Details | EMDB XML:
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-Supplemental data
-Additional map: #1
| File | emd_48342_additional_1.map | ||||||||||||
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| Density Histograms |
-Half map: Half map, B
| File | emd_48342_half_map_1.map | ||||||||||||
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| Annotation | Half map, B | ||||||||||||
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| Density Histograms |
-Half map: Half map, A
| File | emd_48342_half_map_2.map | ||||||||||||
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| Annotation | Half map, A | ||||||||||||
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Sample components
-Entire : acid-sensing ion channel 5 with calcium
| Entire | Name: acid-sensing ion channel 5 with calcium |
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| Components |
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-Supramolecule #1: acid-sensing ion channel 5 with calcium
| Supramolecule | Name: acid-sensing ion channel 5 with calcium / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1 |
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| Source (natural) | Organism: Homo sapiens (human) |
-Macromolecule #1: Acid-sensing ion channel 5
| Macromolecule | Name: Acid-sensing ion channel 5 / type: protein_or_peptide / ID: 1 / Number of copies: 3 / Enantiomer: LEVO |
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| Source (natural) | Organism: Homo sapiens (human) |
| Molecular weight | Theoretical: 57.531012 KDa |
| Recombinant expression | Organism: Homo sapiens (human) |
| Sequence | String: MEQTEKSKVY AENGLLEKIK LCLSKKPLPS PTERKKFDHD FAISTSFHGI HNIVQNRSKI RRVLWLVVVL GSVSLVTWQI YIRLLNYFT WPTTTSIEVQ YVEKMEFPAV TFCNLNRFQT DAVAKFGVIF FLWHIVSKVL HLQEITANST GSREATDFAA S HQNFSIVE ...String: MEQTEKSKVY AENGLLEKIK LCLSKKPLPS PTERKKFDHD FAISTSFHGI HNIVQNRSKI RRVLWLVVVL GSVSLVTWQI YIRLLNYFT WPTTTSIEVQ YVEKMEFPAV TFCNLNRFQT DAVAKFGVIF FLWHIVSKVL HLQEITANST GSREATDFAA S HQNFSIVE FIRNKGFYLN NSTLLDCEFF GKPCSPKDFA HVFTEYGNCF TFNHGETLQA KRKVSVSGRG LSLLFNVNQE AF TDNPALG FVDAGIIFVI HSPKKVPQFD GLGLLSPVGM HARVTIRQVK TVHQEYPWGE CNPNIKLQNF SSYSTSGCLK ECK AQHIKK QCGCVPFLLP GYGIECDLQK YFSCVSPVLD HIEFKDLCTV GTHNSSCPVS CEEIEYPATI SYSSFPSQKA LKYL SKKLN QSRKYIRENL VKIEINYSDL NYKITQQQKA VSVSELLADL GGQLGLFCGA SLITIIEIIE YLFTNFYWIC IFFLL KISE MTQWTPPPQN HLGNKNRIEE C UniProtKB: Bile acid-sensitive ion channel |
-Macromolecule #2: 2-acetamido-2-deoxy-beta-D-glucopyranose
| Macromolecule | Name: 2-acetamido-2-deoxy-beta-D-glucopyranose / type: ligand / ID: 2 / Number of copies: 15 / Formula: NAG |
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| Molecular weight | Theoretical: 221.208 Da |
| Chemical component information | ![]() ChemComp-NAG: |
-Experimental details
-Structure determination
| Method | cryo EM |
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Processing | single particle reconstruction |
| Aggregation state | particle |
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Sample preparation
| Concentration | 3.5 mg/mL |
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| Buffer | pH: 8 |
| Vitrification | Cryogen name: ETHANE |
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Electron microscopy
| Microscope | TFS KRIOS |
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| Image recording | Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Average electron dose: 50.0 e/Å2 |
| Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
| Electron optics | Illumination mode: SPOT SCAN / Imaging mode: BRIGHT FIELD / Nominal defocus max: 2.5 µm / Nominal defocus min: 0.4 µm |
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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About Yorodumi




Keywords
Homo sapiens (human)
Authors
United States, 3 items
Citation





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Processing
FIELD EMISSION GUN
