+Open data
-Basic information
Entry | Database: PDB / ID: 6vx8 | |||||||||||||||
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Title | bestrophin-2 Ca2+- unbound state 2 (EGTA only) | |||||||||||||||
Components | Bestrophin | |||||||||||||||
Keywords | MEMBRANE PROTEIN / Chloride channel | |||||||||||||||
Function / homology | Function and homology information intracellularly ligand-gated monoatomic ion channel activity / ligand-gated monoatomic anion channel activity / Stimuli-sensing channels / bicarbonate channel activity / bicarbonate transport / chloride channel activity / ligand-gated monoatomic cation channel activity / chloride channel complex / basolateral plasma membrane / plasma membrane Similarity search - Function | |||||||||||||||
Biological species | Bos taurus (cattle) | |||||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.33 Å | |||||||||||||||
Authors | Owji, A.P. / Zhao, Q. / Ji, C. / Kittredge, A. / Hopiavuori, A. / Fu, Z. / Ward, N. / Clarke, O. / Shen, Y. / Zhang, Y. ...Owji, A.P. / Zhao, Q. / Ji, C. / Kittredge, A. / Hopiavuori, A. / Fu, Z. / Ward, N. / Clarke, O. / Shen, Y. / Zhang, Y. / Hendrickson, W.A. / Yang, T. | |||||||||||||||
Funding support | United States, 4items
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Citation | Journal: Nat Struct Mol Biol / Year: 2020 Title: Structural and functional characterization of the bestrophin-2 anion channel. Authors: Aaron P Owji / Qingqing Zhao / Changyi Ji / Alec Kittredge / Austin Hopiavuori / Ziao Fu / Nancy Ward / Oliver B Clarke / Yin Shen / Yu Zhang / Wayne A Hendrickson / Tingting Yang / Abstract: The bestrophin family of calcium (Ca)-activated chloride (Cl) channels, which mediate the influx and efflux of monovalent anions in response to the levels of intracellular Ca, comprises four members ...The bestrophin family of calcium (Ca)-activated chloride (Cl) channels, which mediate the influx and efflux of monovalent anions in response to the levels of intracellular Ca, comprises four members in mammals (bestrophin 1-4). Here we report cryo-EM structures of bovine bestrophin-2 (bBest2) bound and unbound by Ca at 2.4- and 2.2-Å resolution, respectively. The bBest2 structure highlights four previously underappreciated pore-lining residues specifically conserved in Best2 but not in Best1, illustrating the differences between these paralogs. Structure-inspired electrophysiological analysis reveals that, although the channel is sensitive to Ca, it has substantial Ca-independent activity for Cl, reflecting the opening at the cytoplasmic restriction of the ion conducting pathway even when Ca is absent. Moreover, the ion selectivity of bBest2 is controlled by multiple residues, including those involved in gating. | |||||||||||||||
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 | 6vx8.cif.gz | 302.8 KB | Display | PDBx/mmCIF format |
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PDB format | pdb6vx8.ent.gz | 248.7 KB | Display | PDB format |
PDBx/mmJSON format | 6vx8.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 6vx8_validation.pdf.gz | 1.3 MB | Display | wwPDB validaton report |
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Full document | 6vx8_full_validation.pdf.gz | 1.4 MB | Display | |
Data in XML | 6vx8_validation.xml.gz | 52.9 KB | Display | |
Data in CIF | 6vx8_validation.cif.gz | 73.4 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/vx/6vx8 ftp://data.pdbj.org/pub/pdb/validation_reports/vx/6vx8 | HTTPS FTP |
-Related structure data
Related structure data | 21433MC 6vx5C 6vx6C 6vx7C 6vx9C M: map data used to model this data C: citing same article (ref.) |
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Similar structure data |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 47424.754 Da / Num. of mol.: 5 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Bos taurus (cattle) / Gene: BEST2 / Cell line (production host): HEK293S / Production host: Homo sapiens (human) / References: UniProt: E1BF86 #2: Chemical | ChemComp-CL / | #3: Water | ChemComp-HOH / | Has ligand of interest | Y | |
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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: bestrophin-2 (BEST2) calcium-free state 2 (EGTA only) / Type: CELL / Entity ID: #1 / Source: RECOMBINANT |
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Source (natural) | Organism: Bos taurus (cattle) |
Source (recombinant) | Organism: Homo sapiens (human) / Strain: HEK293S |
Buffer solution | pH: 7.8 |
Specimen | Conc.: 0.8 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
-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 |
Image recording | Electron dose: 69.67 e/Å2 / Detector mode: COUNTING / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
-Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||
Symmetry | Point symmetry: C5 (5 fold cyclic) | ||||||||||||
3D reconstruction | Resolution: 2.33 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 120642 / Symmetry type: POINT |