4HFF

Crystal structure of the type VI effector-immunity complex Tae4-Tai4 from Salmonella Typhimurium


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.398 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.186 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure of the type VI effector-immunity complex (Tae4-Tai4) provides novel insights into the inhibition mechanism of the effector by its immunity protein

Zhang, H.Zhang, H.Gao, Z.Q.Wang, W.J.Liu, G.F.Xu, J.H.Su, X.D.Dong, Y.H.

(2013) J.Biol.Chem. 288: 5928-5939

  • DOI: 10.1074/jbc.M112.434357
  • Primary Citation of Related Structures:  4HFK, 4HFL

  • PubMed Abstract: 
  • The type VI secretion system (T6SS), a multisubunit needle-like apparatus, has recently been found to play a role in interspecies interactions. The gram-negative bacteria harboring T6SS (donor) deliver the effectors into their neighboring cells (reci ...

    The type VI secretion system (T6SS), a multisubunit needle-like apparatus, has recently been found to play a role in interspecies interactions. The gram-negative bacteria harboring T6SS (donor) deliver the effectors into their neighboring cells (recipient) to kill them. Meanwhile, the cognate immunity proteins were employed to protect the donor cells against the toxic effectors. Tae4 (type VI amidase effector 4) and Tai4 (type VI amidase immunity 4) are newly identified T6SS effector-immunity pairs. Here, we report the crystal structures of Tae4 from Enterobacter cloacae and Tae4-Tai4 complexes from both E. cloacae and Salmonella typhimurium. Tae4 acts as a DL-endopeptidase and displays a typical N1pC/P60 domain. Unlike Tsi1 (type VI secretion immunity 1), Tai4 is an all-helical protein and forms a dimer in solution. The small angle x-ray scattering study combined with the analytical ultracentrifugation reveal that the Tae4-Tai4 complex is a compact heterotetramer that consists of a Tai4 dimer and two Tae4 molecules in solution. Structure-based mutational analysis of the Tae4-Tai4 interface shows that a helix (α3) of one subunit in dimeric Tai4 plays a major role in binding of Tae4, whereas a protruding loop (L4) in the other subunit is mainly responsible for inhibiting Tae4 activity. The inhibition process requires collaboration between the Tai4 dimer. These results reveal a novel and unique inhibition mechanism in effector-immunity pairs and suggest a new strategy to develop antipathogen drugs.


    Organizational Affiliation

    State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, No. 5 Yiheyuan Road, Beijing 100871, China.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Putative cytoplasmic protein
A
175Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)N/A
Find proteins for Q93IS4 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  Q93IS4
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Putative periplasmic protein
B
104Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)N/A
Find proteins for Q8ZRL5 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  Q8ZRL5
Small Molecules
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: 2.398 Å
  • R-Value Free: 0.226 
  • R-Value Work: 0.186 
  • Space Group: P 61 2 2
Unit Cell:
Length (Å)Angle (°)
a = 63.903α = 90.00
b = 63.903β = 90.00
c = 365.916γ = 120.00
Software Package:
Software NamePurpose
SOLVEphasing
MAR345dtbdata collection
PHENIXrefinement
HKL-2000data scaling
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-01-16
    Type: Initial release
  • Version 1.1: 2013-07-24
    Type: Database references