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Yorodumi- EMDB-2527: The electron crystallography structure of the cAMP-free potassium... -
+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-2527 | |||||||||
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Title | The electron crystallography structure of the cAMP-free potassium channel MloK1 | |||||||||
Map data | MloK1 without cAMP | |||||||||
Sample |
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Keywords | Electron crystallography / 2dx / voltage gated potassium channel / CNBD / 2D crystal | |||||||||
Function / homology | Function and homology information transport / potassium channel activity / membrane => GO:0016020 / monoatomic ion transport / cAMP binding / potassium ion transmembrane transport / potassium ion transport / nucleotide binding / protein-containing complex binding / identical protein binding ...transport / potassium channel activity / membrane => GO:0016020 / monoatomic ion transport / cAMP binding / potassium ion transmembrane transport / potassium ion transport / nucleotide binding / protein-containing complex binding / identical protein binding / membrane / plasma membrane Similarity search - Function | |||||||||
Biological species | Mesorhizobium loti (bacteria) | |||||||||
Method | electron crystallography / cryo EM / Resolution: 7.0 Å | |||||||||
Authors | Kowal J / Chami M / Baumgartner P / Arheit M / Chiu P-L / Rangl M / Scheuring S / Schroeder GF / Nimigean CM / Stahlberg H | |||||||||
Citation | Journal: Nat Commun / Year: 2014 Title: Ligand-induced structural changes in the cyclic nucleotide-modulated potassium channel MloK1. Authors: Julia Kowal / Mohamed Chami / Paul Baumgartner / Marcel Arheit / Po-Lin Chiu / Martina Rangl / Simon Scheuring / Gunnar F Schröder / Crina M Nimigean / Henning Stahlberg / Abstract: Cyclic nucleotide-modulated ion channels are important for signal transduction and pacemaking in eukaryotes. The molecular determinants of ligand gating in these channels are still unknown, mainly ...Cyclic nucleotide-modulated ion channels are important for signal transduction and pacemaking in eukaryotes. The molecular determinants of ligand gating in these channels are still unknown, mainly because of a lack of direct structural information. Here we report ligand-induced conformational changes in full-length MloK1, a cyclic nucleotide-modulated potassium channel from the bacterium Mesorhizobium loti, analysed by electron crystallography and atomic force microscopy. Upon cAMP binding, the cyclic nucleotide-binding domains move vertically towards the membrane, and directly contact the S1-S4 voltage sensor domains. This is accompanied by a significant shift and tilt of the voltage sensor domain helices. In both states, the inner pore-lining helices are in an 'open' conformation. We propose a mechanism in which ligand binding can favour pore opening via a direct interaction between the cyclic nucleotide-binding domains and voltage sensors. This offers a simple mechanistic hypothesis for the coupling between ligand gating and voltage sensing in eukaryotic HCN channels. | |||||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | EM map: SurfViewMolmilJmol/JSmol |
Supplemental images |
-Downloads & links
-EMDB archive
Map data | emd_2527.map.gz | 4.1 MB | EMDB map data format | |
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Header (meta data) | emd-2527-v30.xml emd-2527.xml | 13.1 KB 13.1 KB | Display Display | EMDB header |
Images | EMD-2527.png | 129.1 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-2527 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-2527 | HTTPS FTP |
-Validation report
Summary document | emd_2527_validation.pdf.gz | 224 KB | Display | EMDB validaton report |
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Full document | emd_2527_full_validation.pdf.gz | 223.2 KB | Display | |
Data in XML | emd_2527_validation.xml.gz | 5.3 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-2527 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-2527 | HTTPS FTP |
-Related structure data
Related structure data | 4chwMC 2526C 4chvC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data | |
EM raw data | EMPIAR-10006 (Title: 2D crystal images of the potassium channel MloK1 with and without cAMP ligand Data size: 11.6 Data #1: Potassium channel MloK1 with cAMP ligand [micrographs - single frame] Data #2: Potassium channel MloK1 without cAMP ligand [micrographs - single frame]) |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_2527.map.gz / Format: CCP4 / Size: 4.6 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | MloK1 without cAMP | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.975 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
-Sample components
-Entire : MloK1 without cAMP
Entire | Name: MloK1 without cAMP |
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Components |
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-Supramolecule #1000: MloK1 without cAMP
Supramolecule | Name: MloK1 without cAMP / type: sample / ID: 1000 / Oligomeric state: tetramer / Number unique components: 1 |
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Molecular weight | Theoretical: 148 KDa Method: Calculated from sequence for the tetrameric assembly. Lipids are not included. |
-Macromolecule #1: MloK1
Macromolecule | Name: MloK1 / type: protein_or_peptide / ID: 1 / Name.synonym: MlotiK1 / Details: cAMP not present in buffer / Number of copies: 4 / Oligomeric state: Tetramer / Recombinant expression: Yes |
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Source (natural) | Organism: Mesorhizobium loti (bacteria) / synonym: Rhizobium / Location in cell: Membrane |
Molecular weight | Theoretical: 148 KDa |
Recombinant expression | Organism: Escherichia coli BL21(DE3) (bacteria) / Recombinant plasmid: pASK90 |
Sequence | UniProtKB: Cyclic nucleotide-gated potassium channel mll3241 GO: transport, monoatomic ion transport, potassium ion transport, potassium ion transmembrane transport, nucleotide binding, potassium channel activity, cAMP binding, plasma membrane, membrane, membrane => GO:0016020 InterPro: Potassium channel domain, Cyclic nucleotide-binding domain superfamily, Cyclic nucleotide-binding, conserved site, Cyclic nucleotide-binding domain, INTERPRO: IPR003091, 1-aminocyclopropane- ...InterPro: Potassium channel domain, Cyclic nucleotide-binding domain superfamily, Cyclic nucleotide-binding, conserved site, Cyclic nucleotide-binding domain, INTERPRO: IPR003091, 1-aminocyclopropane-1-carboxylate deaminase/D-cysteine desulfhydrase, RmlC-like jelly roll fold |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | electron crystallography |
Aggregation state | 2D array |
-Sample preparation
Concentration | 0.7 mg/mL |
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Buffer | pH: 7.6 / Details: 20 mM KCl, 1 mM BaCl2, 1 mM EDTA, 20 mM Tris |
Grid | Details: Holey carbon film (Quantifoil) covered with ultra thin carbon film. Vitrified in crystallization buffer solution by plunge freezing into ethane. |
Vitrification | Cryogen name: ETHANE / Chamber humidity: 90 % / Chamber temperature: 120 K / Instrument: FEI VITROBOT MARK IV / Method: Blot for 3 seconds before plunging |
Details | Dialysis |
Crystal formation | Details: Dialysis |
-Electron microscopy
Microscope | FEI/PHILIPS CM200FEG |
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Temperature | Min: 85 K / Average: 85 K |
Date | Mar 1, 2012 |
Image recording | Category: FILM / Film or detector model: KODAK SO-163 FILM / Digitization - Scanner: PRIMESCAN / Digitization - Sampling interval: 5 µm / Number real images: 78 / Average electron dose: 5 e/Å2 / Od range: 1.4 / Bits/pixel: 16 |
Tilt angle min | 0 |
Electron beam | Acceleration voltage: 200 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.0 mm / Nominal defocus max: 3.077 µm / Nominal defocus min: 0.655 µm / Nominal magnification: 50000 |
Sample stage | Specimen holder model: GATAN LIQUID NITROGEN / Tilt angle max: 46 / Tilt series - Axis1 - Min angle: 0 ° / Tilt series - Axis1 - Max angle: 46 ° |
-Image processing
Details | 2dx |
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Final reconstruction | Resolution.type: BY AUTHOR / Resolution: 7.0 Å / Resolution method: OTHER / Software - Name: 2dx / Details: Resolution was limited to 7 x 7 x 12 Angstroems |
Crystal parameters | Unit cell - A: 130 Å / Unit cell - B: 130 Å / Unit cell - C: 400 Å / Unit cell - γ: 90.0 ° / Unit cell - α: 90.0 ° / Unit cell - β: 90.0 ° / Plane group: P 4 21 2 |