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Open data
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Basic information
Entry | Database: PDB / ID: 8d1m | ||||||||||||
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Title | hBest1 Ca2+-unbound closed state | ||||||||||||
![]() | Bestrophin-1 | ||||||||||||
![]() | TRANSPORT PROTEIN / Ion channel / chloride channel / anion channel / pentamer | ||||||||||||
Function / homology | ![]() membrane microdomain / bicarbonate channel activity / transepithelial chloride transport / gamma-aminobutyric acid secretion, neurotransmission / detection of light stimulus involved in visual perception / ligand-gated channel activity / intracellularly calcium-gated chloride channel activity / glutamate secretion / bicarbonate transmembrane transporter activity / chloride transport ...membrane microdomain / bicarbonate channel activity / transepithelial chloride transport / gamma-aminobutyric acid secretion, neurotransmission / detection of light stimulus involved in visual perception / ligand-gated channel activity / intracellularly calcium-gated chloride channel activity / glutamate secretion / bicarbonate transmembrane transporter activity / chloride transport / chloride channel activity / regulation of calcium ion transport / chloride channel complex / monoatomic ion transmembrane transport / visual perception / basal plasma membrane / regulation of synaptic plasticity / Stimuli-sensing channels / protein complex oligomerization / presynapse / basolateral plasma membrane / identical protein binding / membrane / plasma membrane / cytosol Similarity search - Function | ||||||||||||
Biological species | ![]() | ||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.11 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 | ![]() | 346.6 KB | Display | ![]() |
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PDB format | ![]() | 281.5 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 27135MC ![]() 8d1eC ![]() 8d1fC ![]() 8d1gC ![]() 8d1hC ![]() 8d1iC ![]() 8d1jC ![]() 8d1kC ![]() 8d1lC ![]() 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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Components
#1: Protein | Mass: 67760.469 Da / Num. of mol.: 5 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
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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: hBest1 Ca2+-unbound closed state / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT | ||||||||||||||||||||
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Molecular weight | Value: 0.338 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 | ||||||||||||||||||||
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: 5558 |
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: 2079411 | ||||||||||||||||||||||||||||||
Symmetry | Point symmetry: C5 (5 fold cyclic) | ||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 3.11 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 94625 / Symmetry type: POINT |