3PCR

Structure of EspG-Arf6 complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.326 
  • R-Value Work: 0.223 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The assembly of a GTPase-kinase signalling complex by a bacterial catalytic scaffold.

Selyunin, A.S.Sutton, S.E.Weigele, B.A.Reddick, L.E.Orchard, R.C.Bresson, S.M.Tomchick, D.R.Alto, N.M.

(2011) Nature 469: 107-111

  • DOI: 10.1038/nature09593
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The fidelity and specificity of information flow within a cell is controlled by scaffolding proteins that assemble and link enzymes into signalling circuits. These circuits can be inhibited by bacterial effector proteins that post-translationally mod ...

    The fidelity and specificity of information flow within a cell is controlled by scaffolding proteins that assemble and link enzymes into signalling circuits. These circuits can be inhibited by bacterial effector proteins that post-translationally modify individual pathway components. However, there is emerging evidence that pathogens directly organize higher-order signalling networks through enzyme scaffolding, and the identity of the effectors and their mechanisms of action are poorly understood. Here we identify the enterohaemorrhagic Escherichia coli O157:H7 type III effector EspG as a regulator of endomembrane trafficking using a functional screen, and report ADP-ribosylation factor (ARF) GTPases and p21-activated kinases (PAKs) as its relevant host substrates. The 2.5 Å crystal structure of EspG in complex with ARF6 shows how EspG blocks GTPase-activating-protein-assisted GTP hydrolysis, revealing a potent mechanism of GTPase signalling inhibition at organelle membranes. In addition, the 2.8 Å crystal structure of EspG in complex with the autoinhibitory Iα3-helix of PAK2 defines a previously unknown catalytic site in EspG and provides an allosteric mechanism of kinase activation by a bacterial effector. Unexpectedly, ARF and PAKs are organized on adjacent surfaces of EspG, indicating its role as a 'catalytic scaffold' that effectively reprograms cellular events through the functional assembly of GTPase-kinase signalling complex.


    Organizational Affiliation

    Department of Microbiology, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-8816, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
EspG
A
357Escherichia coli O157:H7Mutation(s): 0 
Gene Names: espG
Find proteins for Q7DB50 (Escherichia coli O157:H7)
Go to UniProtKB:  Q7DB50
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
ADP-ribosylation factor 6
B
162Homo sapiensMutation(s): 0 
Gene Names: ARF6
Find proteins for P62330 (Homo sapiens)
Go to Gene View: ARF6
Go to UniProtKB:  P62330
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GTP
Query on GTP

Download SDF File 
Download CCD File 
B
GUANOSINE-5'-TRIPHOSPHATE
C10 H16 N5 O14 P3
XKMLYUALXHKNFT-UUOKFMHZSA-N
 Ligand Interaction
MG
Query on MG

Download SDF File 
Download CCD File 
B
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.326 
  • R-Value Work: 0.223 
  • Space Group: P 43 21 2
Unit Cell:
Length (Å)Angle (°)
a = 104.566α = 90.00
b = 104.566β = 90.00
c = 98.238γ = 90.00
Software Package:
Software NamePurpose
HKL-3000data reduction
PHENIXrefinement
HKL-3000data collection
SCALEPACKdata scaling
MLPHAREphasing
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2011-01-05
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Source and taxonomy, Version format compliance