4WJ1

Crystal structure of EspB from the ESX-1 type VII secretion system


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.415 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.175 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of EspB from the ESX-1 type VII secretion system and insights into its export mechanism.

Solomonson, M.Setiaputra, D.Makepeace, K.A.Lameignere, E.Petrotchenko, E.V.Conrady, D.G.Bergeron, J.R.Vuckovic, M.DiMaio, F.Borchers, C.H.Yip, C.K.Strynadka, N.C.

(2015) Structure 23: 571-583

  • DOI: 10.1016/j.str.2015.01.002
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Mycobacterium tuberculosis (Mtb) uses the ESX-1 type VII secretion system to export virulence proteins across its lipid-rich cell wall, which helps permeabilize the host's macrophage phagosomal membrane, facilitating the escape and cell-to-cell sprea ...

    Mycobacterium tuberculosis (Mtb) uses the ESX-1 type VII secretion system to export virulence proteins across its lipid-rich cell wall, which helps permeabilize the host's macrophage phagosomal membrane, facilitating the escape and cell-to-cell spread of Mtb. ESX-1 membranolytic activity depends on a set of specialized secreted Esp proteins, the structure and specific roles of which are not currently understood. Here, we report the X-ray and electron microscopic structures of the ESX-1-secreted EspB. We demonstrate that EspB adopts a PE/PPE-like fold that mediates oligomerization with apparent heptameric symmetry, generating a barrel-shaped structure with a central pore that we propose contributes to the macrophage killing functions of EspB. Our structural data also reveal unexpected direct interactions between the EspB bipartite secretion signal sequence elements that form a unified aromatic surface. These findings provide insight into how specialized proteins encoded within the ESX-1 locus are targeted for secretion, and for the first time indicate an oligomerization-dependent role for Esp virulence factors.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, Life Sciences Centre, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada; Centre for Blood Research, Life Sciences Centre, The University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z3, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Antigen MTB48, Mycobacterial protein
A
291Mycobacterium smegmatis (strain ATCC 700084 / mc(2)155)Mutation(s): 0 
Find proteins for A0QNK4 (Mycobacterium smegmatis (strain ATCC 700084 / mc(2)155))
Go to UniProtKB:  A0QNK4
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.415 Å
  • R-Value Free: 0.201 
  • R-Value Work: 0.175 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 125.749α = 90.00
b = 125.749β = 90.00
c = 75.061γ = 120.00
Software Package:
Software NamePurpose
Aimlessdata scaling
PHENIXrefinement
PDB_EXTRACTdata extraction
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2015-02-25
    Type: Initial release
  • Version 1.1: 2015-08-19
    Type: Database references
  • Version 1.2: 2017-11-22
    Type: Database references, Derived calculations, Refinement description