+Open data
-Basic information
Entry | Database: PDB / ID: 8bx7 | ||||||
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Title | Structure of the rod CNG channel bound to calmodulin | ||||||
Components |
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Keywords | MEMBRANE PROTEIN / CNG channel / calmodulin / rod photoreceptor / vision | ||||||
Function / homology | Function and homology information non-motile cilium membrane / intracellular cyclic nucleotide activated cation channel complex / intracellularly cGMP-activated cation channel activity / rod photoreceptor outer segment / intracellularly cAMP-activated cation channel activity / Inactivation, recovery and regulation of the phototransduction cascade / Activation of the phototransduction cascade / molecular sequestering activity / retina homeostasis / sodium channel activity ...non-motile cilium membrane / intracellular cyclic nucleotide activated cation channel complex / intracellularly cGMP-activated cation channel activity / rod photoreceptor outer segment / intracellularly cAMP-activated cation channel activity / Inactivation, recovery and regulation of the phototransduction cascade / Activation of the phototransduction cascade / molecular sequestering activity / retina homeostasis / sodium channel activity / photoreceptor outer segment membrane / sodium ion transport / monoatomic cation transmembrane transport / monoatomic cation transport / cGMP binding / photoreceptor outer segment / transmembrane transporter complex / cAMP binding / visual perception / calcium channel activity / potassium ion transport / sensory perception of smell / calcium ion transport / molecular adaptor activity / protein-containing complex binding / positive regulation of gene expression / protein homodimerization activity / protein-containing complex / identical protein binding / plasma membrane / cytoplasm Similarity search - Function | ||||||
Biological species | Bos taurus (cattle) | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.76 Å | ||||||
Authors | Marino, J. | ||||||
Funding support | Switzerland, 1items
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Citation | Journal: Proc Natl Acad Sci U S A / Year: 2023 Title: Structural basis of calmodulin modulation of the rod cyclic nucleotide-gated channel. Authors: Diane C A Barret / Dina Schuster / Matthew J Rodrigues / Alexander Leitner / Paola Picotti / Gebhard F X Schertler / U Benjamin Kaupp / Volodymyr M Korkhov / Jacopo Marino / Abstract: Calmodulin (CaM) regulates many ion channels to control calcium entry into cells, and mutations that alter this interaction are linked to fatal diseases. The structural basis of CaM regulation ...Calmodulin (CaM) regulates many ion channels to control calcium entry into cells, and mutations that alter this interaction are linked to fatal diseases. The structural basis of CaM regulation remains largely unexplored. In retinal photoreceptors, CaM binds to the CNGB subunit of cyclic nucleotide-gated (CNG) channels and, thereby, adjusts the channel's Cyclic guanosine monophosphate (cGMP) sensitivity in response to changes in ambient light conditions. Here, we provide the structural characterization for CaM regulation of a CNG channel by using a combination of single-particle cryo-electron microscopy and structural proteomics. CaM connects the CNGA and CNGB subunits, resulting in structural changes both in the cytosolic and transmembrane regions of the channel. Cross-linking and limited proteolysis-coupled mass spectrometry mapped the conformational changes induced by CaM in vitro and in the native membrane. We propose that CaM is a constitutive subunit of the rod channel to ensure high sensitivity in dim light. Our mass spectrometry-based approach is generally relevant for studying the effect of CaM on ion channels in tissues of medical interest, where only minute quantities are available. | ||||||
History |
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-Structure visualization
Structure viewer | Molecule: MolmilJmol/JSmol |
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-Downloads & links
-Download
PDBx/mmCIF format | 8bx7.cif.gz | 424.5 KB | Display | PDBx/mmCIF format |
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PDB format | pdb8bx7.ent.gz | 323 KB | Display | PDB format |
PDBx/mmJSON format | 8bx7.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 8bx7_validation.pdf.gz | 1.2 MB | Display | wwPDB validaton report |
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Full document | 8bx7_full_validation.pdf.gz | 1.3 MB | Display | |
Data in XML | 8bx7_validation.xml.gz | 68.4 KB | Display | |
Data in CIF | 8bx7_validation.cif.gz | 102.1 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/bx/8bx7 ftp://data.pdbj.org/pub/pdb/validation_reports/bx/8bx7 | HTTPS FTP |
-Related structure data
Related structure data | 16311MC M: map data used to model this data C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
-Assembly
Deposited unit |
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1 |
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-Components
#1: Protein | Mass: 155228.562 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Bos taurus (cattle) / References: UniProt: Q28181 | ||
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#2: Protein | Mass: 79712.164 Da / Num. of mol.: 3 / Source method: isolated from a natural source / Source: (natural) Bos taurus (cattle) / References: UniProt: Q00194 #3: Protein | | Mass: 16852.545 Da / Num. of mol.: 1 / Source method: isolated from a natural source / Source: (natural) Bos taurus (cattle) / References: UniProt: A0A3Q7XW08 |
-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: Native CNG channel from retinal rods / Type: COMPLEX / Entity ID: all / Source: NATURAL |
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Molecular weight | Value: 0.41 MDa / Experimental value: NO |
Source (natural) | Organism: Bos taurus (cattle) |
Buffer solution | pH: 7.5 |
Specimen | Conc.: 0.3 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Specimen support | Grid material: COPPER / Grid type: Quantifoil R2/2 |
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277.15 K |
-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 / Nominal defocus max: 2200 nm / Nominal defocus min: 800 nm |
Image recording | Electron dose: 62 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) |
-Processing
Software |
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EM software |
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CTF correction | Type: NONE | ||||||||||||||||||||||||
3D reconstruction | Resolution: 2.76 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 279337 / Symmetry type: POINT | ||||||||||||||||||||||||
Refinement | Cross valid method: NONE | ||||||||||||||||||||||||
Refine LS restraints |
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