+
Open data
-
Basic information
| Entry | Database: EMDB / ID: EMD-11209 | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Title | GLIC pentameric ligand-gated ion channel, pH 3 | |||||||||
 Map data | GLIC, pentameric ligand-gated ion channel, pH 3, sharpened map | |||||||||
 Sample | 
  | |||||||||
 Keywords | GLIC / pentameric ligand-gated ion channel / cryoem / MEMBRANE PROTEIN | |||||||||
| Function / homology |  Function and homology informationsodium channel activity / potassium channel activity / extracellular ligand-gated monoatomic ion channel activity / transmembrane signaling receptor activity / identical protein binding / plasma membrane Similarity search - Function  | |||||||||
| Biological species |  Gloeobacter violaceus (strain ATCC 29082 / PCC 7421) (bacteria) | |||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 3.6 Å | |||||||||
 Authors | Rovsnik U / Zhuang Y | |||||||||
| Funding support |   Sweden, 2 items 
  | |||||||||
 Citation |  Journal: Life Sci Alliance / Year: 2021Title: Dynamic closed states of a ligand-gated ion channel captured by cryo-EM and simulations. Authors: Urška Rovšnik / Yuxuan Zhuang / Björn O Forsberg / Marta Carroni / Linnea Yvonnesdotter / Rebecca J Howard / Erik Lindahl /   ![]() Abstract: Ligand-gated ion channels are critical mediators of electrochemical signal transduction across evolution. Biophysical and pharmacological characterization of these receptor proteins relies on high- ...Ligand-gated ion channels are critical mediators of electrochemical signal transduction across evolution. Biophysical and pharmacological characterization of these receptor proteins relies on high-quality structures in multiple, subtly distinct functional states. However, structural data in this family remain limited, particularly for resting and intermediate states on the activation pathway. Here, we report cryo-electron microscopy (cryo-EM) structures of the proton-activated ligand-gated ion channel (GLIC) under three pH conditions. Decreased pH was associated with improved resolution and side chain rearrangements at the subunit/domain interface, particularly involving functionally important residues in the β1-β2 and M2-M3 loops. Molecular dynamics simulations substantiated flexibility in the closed-channel extracellular domains relative to the transmembrane ones and supported electrostatic remodeling around E35 and E243 in proton-induced gating. Exploration of secondary cryo-EM classes further indicated a low-pH population with an expanded pore. These results allow us to define distinct protonation and activation steps in pH-stimulated conformational cycling in GLIC, including interfacial rearrangements largely conserved in the pentameric channel family.  | |||||||||
| History | 
  | 
-
Structure visualization
| Movie | 
 
 
  Movie viewer | 
|---|---|
| Structure viewer | EM map:  SurfView Molmil Jmol/JSmol | 
| Supplemental images | 
-
Downloads & links
-EMDB archive
| Map data |  emd_11209.map.gz | 7.6 MB |  EMDB map data format | |
|---|---|---|---|---|
| Header (meta data) |  emd-11209-v30.xml emd-11209.xml | 19.5 KB 19.5 KB  | Display Display  |  EMDB header | 
| FSC (resolution estimation) |  emd_11209_fsc.xml | 9.2 KB | Display |  FSC data file | 
| Images |  emd_11209.png | 150.3 KB | ||
| Masks |  emd_11209_msk_1.map | 64 MB |  Mask map | |
| Filedesc metadata |  emd-11209.cif.gz | 5.8 KB | ||
| Others |  emd_11209_additional_1.map.gz emd_11209_half_map_1.map.gz emd_11209_half_map_2.map.gz | 49.6 MB 49.8 MB 49.8 MB  | ||
| Archive directory |  http://ftp.pdbj.org/pub/emdb/structures/EMD-11209 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-11209 | HTTPS FTP  | 
-Validation report
| Summary document |  emd_11209_validation.pdf.gz | 681.6 KB | Display |  EMDB validaton report | 
|---|---|---|---|---|
| Full document |  emd_11209_full_validation.pdf.gz | 681.2 KB | Display | |
| Data in XML |  emd_11209_validation.xml.gz | 15.8 KB | Display | |
| Data in CIF |  emd_11209_validation.cif.gz | 20.9 KB | Display | |
| Arichive directory |  https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-11209 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-11209 | HTTPS FTP  | 
-Related structure data
| Related structure data | ![]() 6zgkMC ![]() 6zgdC ![]() 6zgjC M: atomic model generated by this map C: citing same article (  | 
|---|---|
| Similar structure data | 
-
Links
| EMDB pages |  EMDB (EBI/PDBe) /  EMDataResource | 
|---|---|
| Related items in Molecule of the Month | 
-
Map
| File |  Download / File: emd_11209.map.gz / Format: CCP4 / Size: 64 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Annotation | GLIC, pentameric ligand-gated ion channel, pH 3, sharpened map | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Projections & slices | Image control
 
 Images are generated by Spider.  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Voxel size | X=Y=Z: 0.82 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Density | 
  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Details | EMDB XML: 
 CCP4 map header: 
  | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
-Supplemental data
-Mask #1
| File |  emd_11209_msk_1.map | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Projections & Slices | 
  | ||||||||||||
| Density Histograms | 
-Additional map: GLIC, pentameric ligand-gated ion channel, pH 3, unsharpened map
| File | emd_11209_additional_1.map | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Annotation | GLIC, pentameric ligand-gated ion channel, pH 3, unsharpened map | ||||||||||||
| Projections & Slices | 
  | ||||||||||||
| Density Histograms | 
-Half map: GLIC, pentameric ligand-gated ion channel, pH 3, half map 1
| File | emd_11209_half_map_1.map | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Annotation | GLIC, pentameric ligand-gated ion channel, pH 3, half map 1 | ||||||||||||
| Projections & Slices | 
  | ||||||||||||
| Density Histograms | 
-Half map: GLIC, pentameric ligand-gated ion channel, pH 3, half map 2
| File | emd_11209_half_map_2.map | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Annotation | GLIC, pentameric ligand-gated ion channel, pH 3, half map 2 | ||||||||||||
| Projections & Slices | 
  | ||||||||||||
| Density Histograms | 
-
Sample components
-Entire : Pentameric ion channel
| Entire | Name: Pentameric ion channel | 
|---|---|
| Components | 
  | 
-Supramolecule #1: Pentameric ion channel
| Supramolecule | Name: Pentameric ion channel / type: complex / ID: 1 / Parent: 0 / Macromolecule list: all | 
|---|---|
| Source (natural) | Organism:  Gloeobacter violaceus (strain ATCC 29082 / PCC 7421) (bacteria) | 
| Molecular weight | Theoretical: 180 KDa | 
-Macromolecule #1: Proton-gated ion channel
| Macromolecule | Name: Proton-gated ion channel / type: protein_or_peptide / ID: 1 / Number of copies: 5 / Enantiomer: LEVO | 
|---|---|
| Source (natural) | Organism:  Gloeobacter violaceus (strain ATCC 29082 / PCC 7421) (bacteria)Strain: ATCC 29082 / PCC 7421  | 
| Molecular weight | Theoretical: 36.29175 KDa | 
| Recombinant expression | Organism: ![]()  | 
| Sequence | String: AQDMVSPPPP IADEPLTVNT GIYLIECYSL DDKAETFKVN AFLSLSWKDR RLAFDPVRSG VRVKTYEPEA IWIPEIRFVN  VENARDADV VDISVSPDGT VQYLERFSAR VLSPLDFRRY PFDSQTLHIY LIVRSVDTRN IVLAVDLEKV GKNDDVFLTG W DIESFTAV  ...String:  AQDMVSPPPP IADEPLTVNT GIYLIECYSL DDKAETFKVN AFLSLSWKDR RLAFDPVRSG VRVKTYEPEA IWIPEIRFVN  VENARDADV VDISVSPDGT VQYLERFSAR VLSPLDFRRY PFDSQTLHIY LIVRSVDTRN IVLAVDLEKV GKNDDVFLTG W DIESFTAV VKPANFALED RLESKLDYQL RISRQYFSYI PNIILPMLFI LFISWTAFWS TSYEANVTLV VSTLIAHIAF NI LVETNLP KTPYMTYTGA IIFMIYLFYF VAVIEVTVQH YLKVESQPAR AASITRASRI AFPVVFLLAN IILAFLFFGF UniProtKB: Proton-gated ion channel  | 
-Experimental details
-Structure determination
| Method | cryo EM | 
|---|---|
 Processing | single particle reconstruction | 
| Aggregation state | particle | 
-
Sample preparation
| Concentration | 3 mg/mL | 
|---|---|
| Buffer | pH: 3 | 
| Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 295 K / Instrument: FEI VITROBOT MARK IV / Details: blot for 1.5 s force -1. | 
-
Electron microscopy
| Microscope | FEI TITAN KRIOS | 
|---|---|
| Temperature | Min: 80.0 K | 
| Specialist optics | Energy filter - Name: GIF Bioquantum / Energy filter - Slit width: 20 eV | 
| Image recording | Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Detector mode: COUNTING / Digitization - Frames/image: 1-40 / Number grids imaged: 1 / Number real images: 6000 / Average exposure time: 6.0 sec. / Average electron dose: 45.0 e/Å2 | 
| Electron beam | Acceleration voltage: 300 kV / Electron source:  FIELD EMISSION GUN | 
| Electron optics | C2 aperture diameter: 70.0 µm / Calibrated defocus max: 0.0028 µm / Calibrated defocus min: 0.0009000000000000001 µm / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 3.8000000000000003 µm / Nominal defocus min: 2.0 µm / Nominal magnification: 165000 | 
| Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN | 
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company  | 
Movie
Controller
About Yorodumi



Keywords
Gloeobacter violaceus (strain ATCC 29082 / PCC 7421) (bacteria)
Authors
Sweden, 2 items 
Citation
UCSF Chimera















Z (Sec.)
Y (Row.)
X (Col.)





















































Processing


