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Open data
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Basic information
Entry | Database: PDB / ID: 7sgr | |||||||||
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Title | Structure of hemolysin A secretion system HlyB/D complex | |||||||||
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![]() | MEMBRANE PROTEIN / hydrolase / transport | |||||||||
Function / homology | ![]() type I protein secretion system complex / protein secretion by the type I secretion system / ATPase-coupled lipid transmembrane transporter activity / protein secretion / ABC-type transporter activity / peptidase activity / killing of cells of another organism / ATP hydrolysis activity / proteolysis / ATP binding / plasma membrane Similarity search - Function | |||||||||
Biological species | ![]() ![]() | |||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 2.9 Å | |||||||||
![]() | Zhao, H. / Chen, J. | |||||||||
Funding support | ![]() ![]()
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![]() | ![]() Title: The hemolysin A secretion system is a multi-engine pump containing three ABC transporters. Authors: Hongtu Zhao / James Lee / Jue Chen / ![]() Abstract: Type 1 secretion systems (T1SSs) are widespread in pathogenic Gram-negative bacteria, extruding protein substrates following synthesis of the entire polypeptide. The Escherichia coli hemolysin A ...Type 1 secretion systems (T1SSs) are widespread in pathogenic Gram-negative bacteria, extruding protein substrates following synthesis of the entire polypeptide. The Escherichia coli hemolysin A secretion system has long been considered a prototype in structural and mechanistic studies of T1SSs. Three membrane proteins-an inner membrane ABC transporter HlyB, an adaptor protein HlyD, and an outer membrane porin TolC-are required for secretion. However, the stoichiometry and structure of the complex are unknown. Here, cryo-electron microscopy (cryo-EM) structures determined in two conformations reveal that the inner membrane complex is a hetero-dodecameric assembly comprising three HlyB homodimers and six HlyD subunits. Functional studies indicate that oligomerization of HlyB and HlyD is essential for protein secretion and that polypeptides translocate through a canonical ABC transporter pathway in HlyB. Our data suggest that T1SSs entail three ABC transporters, one that functions as a protein channel and two that allosterically power the translocation process. | |||||||||
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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PDBx/mmCIF format | ![]() | 778.1 KB | Display | ![]() |
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PDB format | ![]() | 633.7 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 25116MC ![]() 8dckC M: map data used to model this data C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Links
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Assembly
Deposited unit | ![]()
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1 |
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Components
#1: Protein | Mass: 79621.492 Da / Num. of mol.: 6 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() #2: Protein | Mass: 40748.895 Da / Num. of mol.: 6 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() ![]() ![]() #3: Chemical | ChemComp-6OU / [( Has ligand of interest | N | |
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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 |
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Sample preparation
Component | Name: Membrane protein complex of HlyB and HlyD / Type: COMPLEX / Entity ID: #1 / Source: RECOMBINANT |
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Molecular weight | Value: 0.81 MDa / Experimental value: NO |
Source (natural) | Organism: ![]() ![]() |
Source (recombinant) | Organism: ![]() ![]() |
Buffer solution | pH: 8 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 3000 nm / Nominal defocus min: 1000 nm |
Image recording | Electron dose: 70 e/Å2 / Film or detector model: GATAN K2 SUMMIT (4k x 4k) |
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Processing
CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION |
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3D reconstruction | Resolution: 2.9 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 136123 / Symmetry type: POINT |