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Open data
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Basic information
Entry | Database: PDB / ID: 8d1f | ||||||||||||
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Title | hBest2 5mM Ca2+ (Ca2+-bound) closed state | ||||||||||||
![]() | Bestrophin-2 | ||||||||||||
![]() | TRANSPORT PROTEIN / Ion channel / chloride channel / anion channel / pentamer | ||||||||||||
Function / homology | ![]() intracellularly ligand-gated monoatomic ion channel activity / ligand-gated monoatomic anion channel activity / bicarbonate channel activity / chloride channel activity / ligand-gated monoatomic cation channel activity / chloride channel complex / membrane depolarization / Stimuli-sensing channels / cilium / sensory perception of smell ...intracellularly ligand-gated monoatomic ion channel activity / ligand-gated monoatomic anion channel activity / bicarbonate channel activity / chloride channel activity / ligand-gated monoatomic cation channel activity / chloride channel complex / membrane depolarization / Stimuli-sensing channels / cilium / sensory perception of smell / basolateral plasma membrane / metal ion binding / plasma membrane Similarity search - Function | ||||||||||||
Biological species | ![]() | ||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 1.82 Å | ||||||||||||
![]() | Owji, A.P. / Kittredge, A. / Hendrickson, W.A. / Tingting, Y. | ||||||||||||
Funding support | ![]()
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![]() | ![]() Title: Structures and gating mechanisms of human bestrophin anion channels. Authors: Aaron P Owji / Jiali Wang / Alec Kittredge / Zada Clark / Yu Zhang / Wayne A Hendrickson / Tingting Yang / ![]() Abstract: Bestrophin-1 (Best1) and bestrophin-2 (Best2) are two members of the bestrophin family of calcium (Ca)-activated chloride (Cl) channels with critical involvement in ocular physiology and direct ...Bestrophin-1 (Best1) and bestrophin-2 (Best2) are two members of the bestrophin family of calcium (Ca)-activated chloride (Cl) channels with critical involvement in ocular physiology and direct pathological relevance. Here, we report cryo-EM structures of wild-type human Best1 and Best2 in various states at up to 1.8 Å resolution. Ca-bound Best1 structures illustrate partially open conformations at the two Ca-dependent gates of the channels, in contrast to the fully open conformations observed in Ca-bound Best2, which is in accord with the significantly smaller currents conducted by Best1 in electrophysiological recordings. Comparison of the closed and open states reveals a C-terminal auto-inhibitory segment (AS), which constricts the channel concentrically by wrapping around the channel periphery in an inter-protomer manner and must be released to allow channel opening. Our results demonstrate that removing the AS from Best1 and Best2 results in truncation mutants with similar activities, while swapping the AS between Best1 and Best2 results in chimeric mutants with swapped activities, underlying a key role of the AS in determining paralog specificity among bestrophins. | ||||||||||||
History |
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 705 KB | Display | ![]() |
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PDB format | ![]() | 601.8 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Summary document | ![]() | 2.6 MB | Display | ![]() |
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Full document | ![]() | 2.6 MB | Display | |
Data in XML | ![]() | 72.6 KB | Display | |
Data in CIF | ![]() | 93.4 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 27128MC ![]() 8d1eC ![]() 8d1gC ![]() 8d1hC ![]() 8d1iC ![]() 8d1jC ![]() 8d1kC ![]() 8d1lC ![]() 8d1mC ![]() 8d1nC ![]() 8d1oC M: map data used to model this data C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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1 |
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Components
-Protein , 1 types, 5 molecules CEADB
#1: Protein | Mass: 46796.898 Da / Num. of mol.: 5 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
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-Non-polymers , 5 types, 726 molecules ![](data/chem/img/CA.gif)
![](data/chem/img/DU0.gif)
![](data/chem/img/MC3.gif)
![](data/chem/img/CL.gif)
![](data/chem/img/HOH.gif)
![](data/chem/img/DU0.gif)
![](data/chem/img/MC3.gif)
![](data/chem/img/CL.gif)
![](data/chem/img/HOH.gif)
#2: Chemical | ChemComp-CA / #3: Chemical | ChemComp-DU0 / #4: Chemical | ChemComp-MC3 / #5: Chemical | ChemComp-CL / | #6: Water | ChemComp-HOH / | |
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-Details
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: hBest2 5mM Ca2+ (Ca2+-bound) closed state / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT | ||||||||||||||||||||
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Molecular weight | Value: 0.234 MDa / Experimental value: NO | ||||||||||||||||||||
Source (natural) | Organism: ![]() | ||||||||||||||||||||
Source (recombinant) | Organism: ![]() | ||||||||||||||||||||
Buffer solution | pH: 7.8 | ||||||||||||||||||||
Buffer component |
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Specimen | Conc.: 5 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES / Details: hBest2 5mM Ca2+ (Ca2+-bound) closed state | ||||||||||||||||||||
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 283.15 K |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: TFS KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2000 nm / Nominal defocus min: 1000 nm / Cs: 2.7 mm |
Image recording | Electron dose: 58 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) / Num. of real images: 5114 |
EM imaging optics | Energyfilter slit width: 20 eV |
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Processing
EM software |
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CTF correction | Type: NONE | |||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 3419200 | |||||||||||||||||||||||||||
Symmetry | Point symmetry: C5 (5 fold cyclic) | |||||||||||||||||||||||||||
3D reconstruction | Resolution: 1.82 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 602194 / Symmetry type: POINT |