4JL0

Crystal structure of PcrH in complex with the chaperone binding region of PopB


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.22 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.214 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Membrane and Chaperone Recognition by the Major Translocator Protein PopB of the Type III Secretion System of Pseudomonas aeruginosa.

Discola, K.F.Forster, A.Boulay, F.Simorre, J.P.Attree, I.Dessen, A.Job, V.

(2014) J.Biol.Chem. 289: 3591-3601

  • DOI: 10.1074/jbc.M113.517920

  • PubMed Abstract: 
  • The type III secretion system is a widespread apparatus used by pathogenic bacteria to inject effectors directly into the cytoplasm of eukaryotic cells. A key component of this highly conserved system is the translocon, a pore formed in the host memb ...

    The type III secretion system is a widespread apparatus used by pathogenic bacteria to inject effectors directly into the cytoplasm of eukaryotic cells. A key component of this highly conserved system is the translocon, a pore formed in the host membrane that is essential for toxins to bypass this last physical barrier. In Pseudomonas aeruginosa the translocon is composed of PopB and PopD, both of which before secretion are stabilized within the bacterial cytoplasm by a common chaperone, PcrH. In this work we characterize PopB, the major translocator, in both membrane-associated and PcrH-bound forms. By combining sucrose gradient centrifugation experiments, limited proteolysis, one-dimensional NMR, and β-lactamase reporter assays on eukaryotic cells, we show that PopB is stably inserted into bilayers with its flexible N-terminal domain and C-terminal tail exposed to the outside. In addition, we also report the crystal structure of the complex between PcrH and an N-terminal region of PopB (residues 51-59), which reveals that PopB lies within the concave face of PcrH, employing mostly backbone residues for contact. PcrH is thus the first chaperone whose structure has been solved in complex with both type III secretion systems translocators, revealing that both molecules employ the same surface for binding and excluding the possibility of formation of a ternary complex. The characterization of the major type III secretion system translocon component in both membrane-bound and chaperone-bound forms is a key step for the eventual development of antibacterials that block translocon assembly.


    Organizational Affiliation

    From the Institut de Biologie Structurale, Université Grenoble Alpes, 6 rue Jules Horowitz, 38000 Grenoble, France.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Regulatory protein PcrH
A, B
142Pseudomonas aeruginosaMutation(s): 0 
Gene Names: pcrH (ipgC)
Find proteins for O30528 (Pseudomonas aeruginosa)
Go to UniProtKB:  O30528
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
PopB
C, D
9Pseudomonas aeruginosaMutation(s): 0 
Gene Names: popB
Find proteins for Q840U9 (Pseudomonas aeruginosa)
Go to UniProtKB:  Q840U9
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
TRS
Query on TRS

Download SDF File 
Download CCD File 
A
2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL
TRIS BUFFER
C4 H12 N O3
LENZDBCJOHFCAS-UHFFFAOYSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.22 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.214 
  • Space Group: P 21 2 21
Unit Cell:
Length (Å)Angle (°)
a = 45.100α = 90.00
b = 73.290β = 90.00
c = 98.940γ = 90.00
Software Package:
Software NamePurpose
XSCALEdata scaling
XDSdata reduction
PDB_EXTRACTdata extraction
PHASERphasing
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-12-11
    Type: Initial release
  • Version 1.1: 2014-01-15
    Type: Database references
  • Version 1.2: 2014-03-05
    Type: Database references