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Yorodumi- EMDB-2299: Negative stain EM structure of the PTC3 holotoxin complex (TcdA1,... -
+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-2299 | |||||||||
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Title | Negative stain EM structure of the PTC3 holotoxin complex (TcdA1, TcdB2, TccC3) in prepore state | |||||||||
Map data | Reconstruction of PTC3 holotoxin complex in prepore state | |||||||||
Sample |
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Keywords | Photorabdus / translocation / pore formation / bacterial toxin / ABC toxin / helical toxin | |||||||||
Function / homology | Function and homology information | |||||||||
Biological species | Photorhabdus luminescens (bacteria) | |||||||||
Method | single particle reconstruction / negative staining / Resolution: 24.6 Å | |||||||||
Authors | Gatsogiannis C / Lang A E / Meusch D / Pfaumann V / Hofnagel O / Benz R / Aktories K / Raunser S | |||||||||
Citation | Journal: Nature / Year: 2013 Title: A syringe-like injection mechanism in Photorhabdus luminescens toxins. Authors: Christos Gatsogiannis / Alexander E Lang / Dominic Meusch / Vanda Pfaumann / Oliver Hofnagel / Roland Benz / Klaus Aktories / Stefan Raunser / Abstract: Photorhabdus luminescens is an insect pathogenic bacterium that is symbiotic with entomopathogenic nematodes. On invasion of insect larvae, P. luminescens is released from the nematodes and kills ...Photorhabdus luminescens is an insect pathogenic bacterium that is symbiotic with entomopathogenic nematodes. On invasion of insect larvae, P. luminescens is released from the nematodes and kills the insect through the action of a variety of virulence factors including large tripartite ABC-type toxin complexes (Tcs). Tcs are typically composed of TcA, TcB and TcC proteins and are biologically active only when complete. Functioning as ADP-ribosyltransferases, TcC proteins were identified as the actual functional components that induce actin-clustering, defects in phagocytosis and cell death. However, little is known about the translocation of TcC into the cell by the TcA and TcB components. Here we show that TcA in P. luminescens (TcdA1) forms a transmembrane pore and report its structure in the prepore and pore state determined by cryoelectron microscopy. We find that the TcdA1 prepore assembles as a pentamer forming an α-helical, vuvuzela-shaped channel less than 1.5 nanometres in diameter surrounded by a large outer shell. Membrane insertion is triggered not only at low pH as expected, but also at high pH, explaining Tc action directly through the midgut of insects. Comparisons with structures of the TcdA1 pore inserted into a membrane and in complex with TcdB2 and TccC3 reveal large conformational changes during membrane insertion, suggesting a novel syringe-like mechanism of protein translocation. Our results demonstrate how ABC-type toxin complexes bridge a membrane to insert their lethal components into the cytoplasm of the host cell. We believe that the proposed mechanism is characteristic of the whole ABC-type toxin family. This explanation of toxin translocation is a step towards understanding the host-pathogen interaction and the complex life cycle of P. luminescens and other pathogens, including human pathogenic bacteria, and serves as a strong foundation for the development of biopesticides. | |||||||||
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_2299.map.gz | 5.1 MB | EMDB map data format | |
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Header (meta data) | emd-2299-v30.xml emd-2299.xml | 10.4 KB 10.4 KB | Display Display | EMDB header |
Images | EMD-2299.png | 91.8 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-2299 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-2299 | HTTPS FTP |
-Validation report
Summary document | emd_2299_validation.pdf.gz | 192.2 KB | Display | EMDB validaton report |
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Full document | emd_2299_full_validation.pdf.gz | 191.3 KB | Display | |
Data in XML | emd_2299_validation.xml.gz | 5.3 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-2299 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-2299 | HTTPS FTP |
-Related 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_2299.map.gz / Format: CCP4 / Size: 5.2 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | Reconstruction of PTC3 holotoxin complex in prepore state | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 4.64 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 : PTC3 (TcdA1, TcdB2, TccC3)
Entire | Name: PTC3 (TcdA1, TcdB2, TccC3) |
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Components |
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-Supramolecule #1000: PTC3 (TcdA1, TcdB2, TccC3)
Supramolecule | Name: PTC3 (TcdA1, TcdB2, TccC3) / type: sample / ID: 1000 Oligomeric state: TcdB2/TccC3 bind to one homopentamer of TcdA1 Number unique components: 3 |
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Molecular weight | Experimental: 1.68 MDa / Theoretical: 1.68 MDa |
-Macromolecule #1: TcdA1
Macromolecule | Name: TcdA1 / type: protein_or_peptide / ID: 1 / Name.synonym: Toxin A / Number of copies: 5 / Recombinant expression: Yes |
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Source (natural) | Organism: Photorhabdus luminescens (bacteria) |
Molecular weight | Experimental: 283 KDa / Theoretical: 283 KDa |
Recombinant expression | Organism: Escherichia coli BL21(DE3) (bacteria) / Recombinant strain: CodonPlus Recombinant plasmid: pCR-BluntII-TOPO, subcloned into pET-28a(+) |
Sequence | UniProtKB: TcdA1 |
-Macromolecule #2: TccC3
Macromolecule | Name: TccC3 / type: protein_or_peptide / ID: 2 / Number of copies: 1 / Recombinant expression: Yes |
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Source (natural) | Organism: Photorhabdus luminescens (bacteria) |
Molecular weight | Experimental: 109 KDa / Theoretical: 109 KDa |
Recombinant expression | Organism: Escherichia coli (E. coli) |
Sequence | UniProtKB: Insecticidal toxin complex protein TccC3 |
-Macromolecule #3: TcdB2
Macromolecule | Name: TcdB2 / type: protein_or_peptide / ID: 3 / Number of copies: 1 / Recombinant expression: Yes |
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Source (natural) | Organism: Photorhabdus luminescens (bacteria) |
Molecular weight | Experimental: 166 KDa / Theoretical: 166 KDa |
Recombinant expression | Organism: Escherichia coli (E. coli) |
Sequence | UniProtKB: Insecticidal toxin complex protein TcdB2 |
-Experimental details
-Structure determination
Method | negative staining |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Buffer | pH: 5 Details: 50 mM MES, 100 mM NaCl, 0.05% Tween-20, 5% glycerol |
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Staining | Type: NEGATIVE Details: Grids with adsorbed Protein floated on 0.07% Uranyl Formate for 45 sec. |
Grid | Details: glow discharged 400 mesh copper grids with thin carbon support |
Vitrification | Cryogen name: NONE / Instrument: OTHER |
-Electron microscopy
Microscope | JEOL 1400 |
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Date | Sep 29, 2011 |
Image recording | Category: CCD / Film or detector model: TVIPS TEMCAM-F416 (4k x 4k) / Number real images: 84 |
Electron beam | Acceleration voltage: 120 kV / Electron source: LAB6 |
Electron optics | Calibrated magnification: 67210 / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 3.4 mm / Nominal defocus max: 0.002 µm / Nominal defocus min: 0.0012 µm / Nominal magnification: 50000 |
Sample stage | Specimen holder model: JEOL |
-Image processing
Details | Partial-symmetry projection matching approach (after each refinement round, C5 symmetry was applied for the TcdA1 component) |
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Final reconstruction | Applied symmetry - Point group: C1 (asymmetric) / Algorithm: OTHER / Resolution.type: BY AUTHOR / Resolution: 24.6 Å / Resolution method: FSC 0.5 CUT-OFF / Software - Name: Sparx / Number images used: 3022 |