Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 16.10 kDa 
• Atom Count: 1048 
• Modelled Residue Count: 125 
• Deposited Residue Count: 144 
• Unique protein chains: 1

4LQD

The crystal structures of the Brucella protein TcpB and the TLR adaptor protein TIRAP show structural differences in microbial TIR mimicry

• PDB DOI: 10.2210/pdb4LQD/pdb

• Classification: IMMUNE SYSTEM
• Organism(s): Homo sapiens
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 2013-07-17 Released: 2013-12-04 
• Deposition Author(s): Snyder, G.A., Smith, P., Jiang, J., Xiao, T.S.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.45 Å
• R-Value Free: 0.218 
• R-Value Work: 0.207 
• R-Value Observed: 0.208 

Literature

Crystal structures of the Toll/Interleukin-1 receptor (TIR) domains from the Brucella protein TcpB and host adaptor TIRAP reveal mechanisms of molecular mimicry.

Snyder, G.A., Deredge, D., Waldhuber, A., Fresquez, T., Wilkins, D.Z., Smith, P.T., Durr, S., Cirl, C., Jiang, J., Jennings, W., Luchetti, T., Snyder, N., Sundberg, E.J., Wintrode, P., Miethke, T., Xiao, T.S.

(2014) J Biol Chem 289: 669-679

• PubMed: 24275656 
• DOI: 10.1074/jbc.M113.523407
• Primary Citation of Related Structures:  
  4LQC, 4LQD


• PubMed Abstract: 
  

The Toll/IL-1 receptor (TIR) domains are crucial innate immune signaling modules. Microbial TIR domain-containing proteins inhibit Toll-like receptor (TLR) signaling through molecular mimicry. The TIR domain-containing protein TcpB from Brucella inhibits TLR signaling through interaction with host adaptor proteins TIRAP/Mal and MyD88. To characterize the microbial mimicry of host proteins, we have determined the X-ray crystal structures of the TIR domains from the Brucella protein TcpB and the host adaptor protein TIRAP. We have further characterized homotypic interactions of TcpB using hydrogen/deuterium exchange mass spectrometry and heterotypic TcpB and TIRAP interaction by co-immunoprecipitation and NF-κB reporter assays. The crystal structure of the TcpB TIR domain reveals the microtubule-binding site encompassing the BB loop as well as a symmetrical dimer mediated by the DD and EE loops. This dimerization interface is validated by peptide mapping through hydrogen/deuterium exchange mass spectrometry. The human TIRAP TIR domain crystal structure reveals a unique N-terminal TIR domain fold containing a disulfide bond formed by Cys(89) and Cys(134). A comparison between the TcpB and TIRAP crystal structures reveals substantial conformational differences in the region that encompasses the BB loop. These findings underscore the similarities and differences in the molecular features found in the microbial and host TIR domains, which suggests mechanisms of bacterial mimicry of host signaling adaptor proteins, such as TIRAP.

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Organizational Affiliation: 

From the Laboratory of Immunology, NIAID, National Institutes of Health, Bethesda, Maryland 20892.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Toll/interleukin-1 receptor domain-containing adapter protein	A	144	Homo sapiens	Mutation(s): 0  Gene Names: TIRAP, MAL
UniProt & NIH Common Fund Data Resources
Find proteins for P58753 (Homo sapiens) Explore P58753  Go to UniProtKB:  P58753
PHAROS:  P58753 GTEx:  ENSG00000150455

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
GOL	B [auth A]	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N

Modified Residues  1 Unique
ID	Chains	Type	Formula	2D Diagram	Parent
CME	A	L-PEPTIDE LINKING	C5 H11 N O3 S2		CYS

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.45 Å
• R-Value Free: 0.218 
• R-Value Work: 0.207 
• R-Value Observed: 0.208 
• Space Group: P 4₃ 2₁ 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 87.57	α = 90
b = 87.57	β = 90
c = 80.65	γ = 90

Software Package:

Software Name	Purpose
HKL-2000	data collection
SHELXS	phasing
PHENIX	refinement
HKL-2000	data reduction
HKL-2000	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2013-07-17 
• Released Date: 2013-12-04 
Deposition Author(s): Snyder, G.A., Smith, P., Jiang, J., Xiao, T.S.

Revision History  

• Version 1.0: 2013-12-04
  Type: Initial release
  
• Version 1.1: 2014-04-09
  Changes: Database references