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Open data
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Basic information
Entry | Database: PDB / ID: 6vak | |||||||||
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Title | Cryo-EM structure of human CALHM2 | |||||||||
![]() | Calcium homeostasis modulator protein 2 | |||||||||
![]() | MEMBRANE PROTEIN / assembly / taste | |||||||||
Function / homology | Calcium homeostasis modulator family / Calcium homeostasis modulator / monoatomic cation channel activity / positive regulation of apoptotic process / membrane / Calcium homeostasis modulator protein 2![]() | |||||||||
Biological species | ![]() | |||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.48 Å | |||||||||
![]() | Syrjanen, J.L. / Chou, T.H. / Furukawa, H. | |||||||||
Funding support | ![]()
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![]() | ![]() Title: Structure and assembly of calcium homeostasis modulator proteins. Authors: Johanna L Syrjanen / Kevin Michalski / Tsung-Han Chou / Timothy Grant / Shanlin Rao / Noriko Simorowski / Stephen J Tucker / Nikolaus Grigorieff / Hiro Furukawa / ![]() ![]() Abstract: The biological membranes of many cell types contain large-pore channels through which a wide variety of ions and metabolites permeate. Examples include connexin, innexin and pannexin, which form gap ...The biological membranes of many cell types contain large-pore channels through which a wide variety of ions and metabolites permeate. Examples include connexin, innexin and pannexin, which form gap junctions and/or bona fide cell surface channels. The most recently identified large-pore channels are the calcium homeostasis modulators (CALHMs), through which ions and ATP permeate in a voltage-dependent manner to control neuronal excitability, taste signaling and pathologies of depression and Alzheimer's disease. Despite such critical biological roles, the structures and patterns of their oligomeric assembly remain unclear. Here, we reveal the structures of two CALHMs, chicken CALHM1 and human CALHM2, by single-particle cryo-electron microscopy (cryo-EM), which show novel assembly of the four transmembrane helices into channels of octamers and undecamers, respectively. Furthermore, molecular dynamics simulations suggest that lipids can favorably assemble into a bilayer within the larger CALHM2 pore, but not within CALHM1, demonstrating the potential correlation between pore size, lipid accommodation and channel activity. | |||||||||
History |
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Structure visualization
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 496.5 KB | Display | ![]() |
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PDB format | ![]() | 417.9 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Summary document | ![]() | 987.3 KB | Display | ![]() |
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Full document | ![]() | 1015 KB | Display | |
Data in XML | ![]() | 186 KB | Display | |
Data in CIF | ![]() | 369.5 KB | Display | |
Arichive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
Related structure data | ![]() 21141MC ![]() 6vaiC ![]() 6valC ![]() 6vamC M: map data used to model this data C: citing same article ( |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Protein | Mass: 37468.871 Da / Num. of mol.: 11 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: Undecameric assembly of human calcium homeostasis modulator protein 2 (CALHM2) in EDTA Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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Molecular weight | Experimental value: NO |
Source (natural) | Organism: ![]() |
Source (recombinant) | Organism: ![]() ![]() |
Buffer solution | pH: 7.5 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Specimen support | Details: unspecified |
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 85 % / Chamber temperature: 288.15 K / Details: Blot for 4 sec before plunging |
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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: 70 e/Å2 / 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: C11 (11 fold cyclic) | ||||||||||||
3D reconstruction | Resolution: 3.48 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 104755 / Symmetry type: POINT |