4D3E

Tetramer of IpaD, modified from 2J0O, fitted into negative stain electron microscopy reconstruction of the wild type tip complex from the type III secretion system of Shigella flexneri


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.12 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Three-Dimensional Electron Microscopy Reconstruction and Cysteine-Mediated Crosslinking Provide a Model of the T3Ss Needle Tip Complex.

Cheung, M.Shen, D.Makino, F.Kato, T.Roehrich, A.D.Martinez-Argudo, I.Walker, M.L.Murillo, I.Liu, X.Pain, M.Brown, J.Frazer, G.Mantell, J.Mina, P.Todd, T.Sessions, R.B.Namba, K.Blocker, A.J.

(2015) Mol.Microbiol. 95: 31

  • DOI: 10.1111/mmi.12843

  • PubMed Abstract: 
  • Type III secretion systems are found in many Gram-negative bacteria. They are activated by contact with eukaryotic cells and inject virulence proteins inside them. Host cell detection requires a protein complex located at the tip of the device's exte ...

    Type III secretion systems are found in many Gram-negative bacteria. They are activated by contact with eukaryotic cells and inject virulence proteins inside them. Host cell detection requires a protein complex located at the tip of the device's external injection needle. The Shigella tip complex (TC) is composed of IpaD, a hydrophilic protein, and IpaB, a hydrophobic protein, which later forms part of the injection pore in the host membrane. Here we used labelling and crosslinking methods to show that TCs from a ΔipaB strain contain five IpaD subunits while the TCs from wild-type can also contain one IpaB and four IpaD subunits. Electron microscopy followed by single particle and helical image analysis was used to reconstruct three-dimensional images of TCs at ∼ 20 Å resolution. Docking of an IpaD crystal structure, constrained by the crosslinks observed, reveals that TC organisation is different from that of all previously proposed models. Our findings suggest new mechanisms for TC assembly and function. The TC is the only site within these secretion systems targeted by disease-protecting antibodies. By suggesting how these act, our work will allow improvement of prophylactic and therapeutic strategies.


    Related Citations: 
    • Self-Chaperoning of the Type III Secretion System Needle Tip Proteins Ipad and Bipd
      Johnson, S.,Roversi, P.,Espina, M.,Olive, A.,Deane, J.E.,Birket, S.,Field, T.,Picking, W.D.,Blocker, A.J.,Galyov, E.E.,Picking, W.L.,Lea, S.M.
      (2007) J.Biol.Chem. 282: 4035


    Organizational Affiliation

    Schools of Cellular & Molecular Medicine and Biochemistry, University of Bristol, Bristol, BS8 1TD, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
INVASIN IPAD
D
208Shigella flexneriMutation(s): 0 
Gene Names: ipaD
Find proteins for P18013 (Shigella flexneri)
Go to UniProtKB:  P18013
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 2.12 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2014-12-10
    Type: Initial release
  • Version 1.1: 2015-01-14
    Type: Database references
  • Version 1.2: 2017-08-30
    Type: Data collection
  • Version 1.3: 2018-01-31
    Type: Data processing