+Open data
-Basic information
Entry | Database: PDB / ID: 6i1y | ||||||||||||
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Title | Vibrio vulnificus EpsD | ||||||||||||
Components | General secretion pathway protein GspD | ||||||||||||
Keywords | PROTEIN TRANSPORT | ||||||||||||
Function / homology | Function and homology information protein secretion by the type II secretion system / type II protein secretion system complex / membrane => GO:0016020 / cell outer membrane Similarity search - Function | ||||||||||||
Biological species | Vibrio vulnificus (bacteria) | ||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.4 Å | ||||||||||||
Authors | Contreras-Martel, C. / Farias Estrozi, L. | ||||||||||||
Funding support | France, Canada, 3items
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Citation | Journal: PLoS Pathog / Year: 2019 Title: Structure and assembly of pilotin-dependent and -independent secretins of the type II secretion system. Authors: S Peter Howard / Leandro F Estrozi / Quentin Bertrand / Carlos Contreras-Martel / Timothy Strozen / Viviana Job / Alexandre Martins / Daphna Fenel / Guy Schoehn / Andréa Dessen / Abstract: The type II secretion system (T2SS) is a cell envelope-spanning macromolecular complex that is prevalent in Gram-negative bacterial species. It serves as the predominant virulence mechanism of many ...The type II secretion system (T2SS) is a cell envelope-spanning macromolecular complex that is prevalent in Gram-negative bacterial species. It serves as the predominant virulence mechanism of many bacteria including those of the emerging human pathogens Vibrio vulnificus and Aeromonas hydrophila. The system is composed of a core set of highly conserved proteins that assemble an inner membrane platform, a periplasmic pseudopilus and an outer membrane complex termed the secretin. Localization and assembly of secretins in the outer membrane requires recognition of secretin monomers by two different partner systems: an inner membrane accessory complex or a highly sequence-diverse outer membrane lipoprotein, termed the pilotin. In this study, we addressed the question of differential secretin assembly mechanisms by using cryo-electron microscopy to determine the structures of the secretins from A. hydrophila (pilotin-independent ExeD) and V. vulnificus (pilotin-dependent EpsD). These structures, at approximately 3.5 Å resolution, reveal pentadecameric stoichiometries and C-terminal regions that carry a signature motif in the case of a pilotin-dependent assembly mechanism. We solved the crystal structure of the V. vulnificus EpsS pilotin and confirmed the importance of the signature motif for pilotin-dependent secretin assembly by performing modelling with the C-terminus of EpsD. We also show that secretin assembly is essential for membrane integrity and toxin secretion in V. vulnificus and establish that EpsD requires the coordinated activity of both the accessory complex EpsAB and the pilotin EpsS for full assembly and T2SS function. In contrast, mutation of the region of the S-domain that is normally the site of pilotin interactions has little effect on assembly or function of the ExeD secretin. Since secretins are essential outer membrane channels present in a variety of secretion systems, these results provide a structural and functional basis for understanding the key assembly steps for different members of this vast pore-forming family of proteins. | ||||||||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | Molecule: MolmilJmol/JSmol |
-Downloads & links
-Download
PDBx/mmCIF format | 6i1y.cif.gz | 1.3 MB | Display | PDBx/mmCIF format |
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PDB format | pdb6i1y.ent.gz | 1.1 MB | Display | PDB format |
PDBx/mmJSON format | 6i1y.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 6i1y_validation.pdf.gz | 1020.7 KB | Display | wwPDB validaton report |
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Full document | 6i1y_full_validation.pdf.gz | 1.7 MB | Display | |
Data in XML | 6i1y_validation.xml.gz | 301.8 KB | Display | |
Data in CIF | 6i1y_validation.cif.gz | 431.3 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/i1/6i1y ftp://data.pdbj.org/pub/pdb/validation_reports/i1/6i1y | HTTPS FTP |
-Related structure data
Related structure data | 0327MC 0326C 6i1xC 6i2vC C: citing same article (ref.) M: map data used to model this data |
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Similar structure data |
-Links
-Assembly
Deposited unit |
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-Components
#1: Protein | Mass: 60124.922 Da / Num. of mol.: 15 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Vibrio vulnificus (bacteria) / Gene: JS86_21435 Production host: Cell-free gateway cloning vector N-term 8xHis pCellFree_G01 (others) References: UniProt: A0A087IFK6 |
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-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: EpsD / Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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Molecular weight | Value: 1 MDa / Experimental value: NO |
Source (natural) | Organism: Vibrio vulnificus (bacteria) |
Source (recombinant) | Organism: Cell-free gateway cloning vector N-term 8xHis pCellFree_G01 (others) Plasmid: pIVEX2.4T |
Buffer solution | pH: 7.5 |
Specimen | Conc.: 10 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES / Details: This sample was monodisperse |
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 100 % |
-Electron microscopy imaging
Experimental equipment | Model: Tecnai Polara / Image courtesy: FEI Company |
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Microscopy | Model: FEI POLARA 300 |
Electron gun | Electron source: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD / Calibrated magnification: 41322 X / Cs: 2 mm / Alignment procedure: COMA FREE |
Specimen holder | Cryogen: NITROGEN / Specimen holder model: GATAN LIQUID NITROGEN |
Image recording | Average exposure time: 1 sec. / Electron dose: 40 e/Å2 / Detector mode: COUNTING / Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Num. of real images: 2021 |
Image scans | Movie frames/image: 40 |
-Processing
Software | Name: REFMAC / Version: 5.8.0232 / Classification: refinement | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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EM software |
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Image processing | Details: Image processing performed with motioncor2, Gctf, EMAN and Relion. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Particle selection | Num. of particles selected: 125884 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Symmetry | Point symmetry: C15 (15 fold cyclic) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
3D reconstruction | Resolution: 3.4 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 46126 / Algorithm: FOURIER SPACE / Num. of class averages: 1 / Symmetry type: POINT | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | B value: 146 / Protocol: OTHER / Space: REAL / Target criteria: Cross-correlation coefficient Details: Coot and buccaneer for model building and refmac5 for refinement (CCPEM-1.1.0 suite). | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Atomic model building | PDB-ID: 5WQ8 Accession code: 5WQ8 / Source name: PDB / Type: experimental model | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Refinement | Resolution: 3.4→302.5 Å / Cor.coef. Fo:Fc: 0.833 / SU B: 20 / SU ML: 0.301 / ESU R: 0.268 Stereochemistry target values: MAXIMUM LIKELIHOOD WITH PHASES Details: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS
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Solvent computation | Solvent model: PARAMETERS FOR MASK CACLULATION | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Displacement parameters | Biso mean: 158.591 Å2
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Refinement step | Cycle: 1 / Total: 56520 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Refine LS restraints |
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