+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-21425 | |||||||||
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Title | NaChBac in lipid nanodisc | |||||||||
Map data | ||||||||||
Sample |
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Keywords | NaChBac / Channels / Sodium Ion-Selective / MEMBRANE PROTEIN | |||||||||
Function / homology | Voltage-gated cation channel calcium and sodium / Voltage-dependent channel domain superfamily / monoatomic cation channel activity / Ion transport domain / Ion transport protein / plasma membrane / BH1501 protein Function and homology information | |||||||||
Biological species | Bacillus halodurans C-125 (bacteria) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 3.1 Å | |||||||||
Authors | Yan N / Gao S | |||||||||
Funding support | United States, 1 items
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Citation | Journal: Proc Natl Acad Sci U S A / Year: 2020 Title: Employing NaChBac for cryo-EM analysis of toxin action on voltage-gated Na channels in nanodisc. Authors: Shuai Gao / William C Valinsky / Nguyen Cam On / Patrick R Houlihan / Qian Qu / Lei Liu / Xiaojing Pan / David E Clapham / Nieng Yan / Abstract: NaChBac, the first bacterial voltage-gated Na (Na) channel to be characterized, has been the prokaryotic prototype for studying the structure-function relationship of Na channels. Discovered nearly ...NaChBac, the first bacterial voltage-gated Na (Na) channel to be characterized, has been the prokaryotic prototype for studying the structure-function relationship of Na channels. Discovered nearly two decades ago, the structure of NaChBac has not been determined. Here we present the single particle electron cryomicroscopy (cryo-EM) analysis of NaChBac in both detergent micelles and nanodiscs. Under both conditions, the conformation of NaChBac is nearly identical to that of the potentially inactivated NaAb. Determining the structure of NaChBac in nanodiscs enabled us to examine gating modifier toxins (GMTs) of Na channels in lipid bilayers. To study GMTs in mammalian Na channels, we generated a chimera in which the extracellular fragment of the S3 and S4 segments in the second voltage-sensing domain from Na1.7 replaced the corresponding sequence in NaChBac. Cryo-EM structures of the nanodisc-embedded chimera alone and in complex with HuwenToxin IV (HWTX-IV) were determined to 3.5 and 3.2 Å resolutions, respectively. Compared to the structure of HWTX-IV-bound human Na1.7, which was obtained at an overall resolution of 3.2 Å, the local resolution of the toxin has been improved from ∼6 to ∼4 Å. This resolution enabled visualization of toxin docking. NaChBac can thus serve as a convenient surrogate for structural studies of the interactions between GMTs and Na channels in a membrane environment. | |||||||||
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_21425.map.gz | 48.2 MB | EMDB map data format | |
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Header (meta data) | emd-21425-v30.xml emd-21425.xml | 11.3 KB 11.3 KB | Display Display | EMDB header |
Images | emd_21425.png | 67.7 KB | ||
Filedesc metadata | emd-21425.cif.gz | 5.4 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-21425 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-21425 | HTTPS FTP |
-Validation report
Summary document | emd_21425_validation.pdf.gz | 506.5 KB | Display | EMDB validaton report |
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Full document | emd_21425_full_validation.pdf.gz | 506.1 KB | Display | |
Data in XML | emd_21425_validation.xml.gz | 6 KB | Display | |
Data in CIF | emd_21425_validation.cif.gz | 6.9 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-21425 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-21425 | HTTPS FTP |
-Related structure data
Related structure data | 6vwxMC 6vx3C 6vxoC 6w6oC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_21425.map.gz / Format: CCP4 / Size: 52.7 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.114 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 : NaChBac
Entire | Name: NaChBac |
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Components |
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-Supramolecule #1: NaChBac
Supramolecule | Name: NaChBac / type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1 |
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Source (natural) | Organism: Bacillus halodurans C-125 (bacteria) |
-Macromolecule #1: BH1501 protein
Macromolecule | Name: BH1501 protein / type: protein_or_peptide / ID: 1 / Number of copies: 4 / Enantiomer: LEVO |
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Source (natural) | Organism: Bacillus halodurans C-125 (bacteria) Strain: ATCC BAA-125 / DSM 18197 / FERM 7344 / JCM 9153 / C-125 |
Molecular weight | Theoretical: 31.486197 KDa |
Recombinant expression | Organism: Escherichia coli (E. coli) |
Sequence | String: MKMEARQKQN SFTSKMQKIV NHRAFTFTVI ALILFNALIV GIETYPRIYA DHKWLFYRID LVLLWIFTIE IAMRFLASNP KSAFFRSSW NWFDFLIVAA GHIFAGAQFV TVLRILRVLR VLRAISVVPS LRRLVDALVM TIPALGNILI LMSIFFYIFA V IGTMLFQH ...String: MKMEARQKQN SFTSKMQKIV NHRAFTFTVI ALILFNALIV GIETYPRIYA DHKWLFYRID LVLLWIFTIE IAMRFLASNP KSAFFRSSW NWFDFLIVAA GHIFAGAQFV TVLRILRVLR VLRAISVVPS LRRLVDALVM TIPALGNILI LMSIFFYIFA V IGTMLFQH VSPEYFGNLQ LSLLTLFQVV TLESWASGVM RPIFAEVPWS WLYFVSFVLI GTFIIFNLFI GVIVNNVEKA EL TDNEEDG EADGLKQEIS ALRKDVAELK SLLKQSK UniProtKB: BH1501 protein |
-Macromolecule #2: (2S)-3-(hexadecanoyloxy)-2-[(9Z)-octadec-9-enoyloxy]propyl 2-(tri...
Macromolecule | Name: (2S)-3-(hexadecanoyloxy)-2-[(9Z)-octadec-9-enoyloxy]propyl 2-(trimethylammonio)ethyl phosphate type: ligand / ID: 2 / Number of copies: 8 / Formula: POV |
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Molecular weight | Theoretical: 760.076 Da |
Chemical component information | ChemComp-POV: |
-Macromolecule #3: SODIUM ION
Macromolecule | Name: SODIUM ION / type: ligand / ID: 3 / Number of copies: 2 |
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Molecular weight | Theoretical: 22.99 Da |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 5 mg/mL | |||||||||
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Buffer | pH: 8 Component:
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Grid | Model: Quantifoil R1.2/1.3 / Material: COPPER / Mesh: 300 / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Time: 15 sec. / Pretreatment - Atmosphere: AIR / Pretreatment - Pressure: 38.0 kPa / Details: no | |||||||||
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 281 K / Instrument: FEI VITROBOT MARK IV / Details: blot for 5 seconds before plunging. | |||||||||
Details | NaChBac was in lipid nanodisc |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Average electron dose: 53.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
Startup model | Type of model: OTHER |
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Final reconstruction | Resolution.type: BY AUTHOR / Resolution: 3.1 Å / Resolution method: FSC 0.143 CUT-OFF / Number images used: 281039 |
Initial angle assignment | Type: MAXIMUM LIKELIHOOD |
Final angle assignment | Type: MAXIMUM LIKELIHOOD |