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Open data
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Basic information
Entry | Database: PDB / ID: 6vx9 | |||||||||||||||
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Title | bestrophin-2 Ca2+- unbound state 1 (EGTA only) | |||||||||||||||
![]() | Bestrophin | |||||||||||||||
![]() | MEMBRANE PROTEIN / Chloride Channel | |||||||||||||||
Function / homology | ![]() intracellularly ligand-gated monoatomic ion channel activity / ligand-gated monoatomic anion channel activity / Stimuli-sensing channels / bicarbonate channel activity / ligand-gated monoatomic cation channel activity / bicarbonate transport / chloride channel activity / chloride channel complex / basolateral plasma membrane / plasma membrane Similarity search - Function | |||||||||||||||
Biological species | ![]() ![]() | |||||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.17 Å | |||||||||||||||
![]() | 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 | ![]()
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![]() | ![]() 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
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Structure viewer | Molecule: ![]() ![]() |
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PDBx/mmCIF format | ![]() | 332.6 KB | Display | ![]() |
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PDB format | ![]() | 274.8 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Summary document | ![]() | 1.4 MB | Display | ![]() |
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Full document | ![]() | 1.4 MB | Display | |
Data in XML | ![]() | 57.4 KB | Display | |
Data in CIF | ![]() | 80.3 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 21434MC ![]() 6vx5C ![]() 6vx6C ![]() 6vx7C ![]() 6vx8C M: map data used to model this data C: citing same article ( |
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Similar structure data |
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Assembly
Deposited unit | ![]()
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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.) ![]() ![]() ![]() #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 |
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Sample preparation
Component | Name: bestrophin-2 (BEST2) calcium-free state 1 (EGTA only) / Type: CELL / Entity ID: #1 / Source: RECOMBINANT |
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Source (natural) | Organism: ![]() ![]() |
Source (recombinant) | Organism: ![]() |
Buffer solution | pH: 7.8 |
Specimen | Conc.: 0.8 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE |
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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: ![]() |
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) |
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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: 2.17 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 280524 / Symmetry type: POINT |