Biological Assembly 1  

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

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

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

Macromolecule Content

• Total Structure Weight: 8.56 kDa 
• Atom Count: 632 
• Modelled Residue Count: 76 
• Deposited Residue Count: 76 
• Unique protein chains: 1

1QXX

CRYSTAL STRUCTURE OF THE C-TERMINAL DOMAIN OF TONB

• PDB DOI: 10.2210/pdb1QXX/pdb

• Classification: TRANSPORT PROTEIN
• Organism(s): Escherichia coli
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): No 


• Deposited: 2003-09-09 Released: 2004-04-06 
• Deposition Author(s): Koedding, J., Howard, P., Kaufmann, L., Polzer, P., Lustig, A., Welte, W.

---

Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.70 Å
• R-Value Free: 0.271 
• R-Value Work: 0.267 

Literature

Dimerization of TonB is not essential for its binding to the outer membrane siderophore receptor FhuA of Escherichia coli.

Koedding, J., Howard, P., Kaufmann, L., Polzer, P., Lustig, A., Welte, W.

(2004) J Biol Chem 279: 9978-9986

• PubMed: 14665631 
• DOI: 10.1074/jbc.M311720200
• Primary Citation of Related Structures:  
  1QXX


• PubMed Abstract: 
  

FhuA belongs to a family of specific siderophore transport systems located in the outer membrane of Escherichia coli. The energy required for the transport process is provided by the proton motive force of the cytoplasmic membrane and is transmitted to FhuA by the protein TonB. Although the structure of full-length TonB is not known, the structure of the last 77 residues of a fragment composed of the 86 C-terminal amino acids was recently solved and shows an intertwined dimer (Chang, C., Mooser, A., Pluckthun, A., and Wlodawer, A. (2001) J. Biol. Chem. 276, 27535-27540). We analyzed the ability of truncated C-terminal TonB fragments of different lengths (77, 86, 96, 106, 116, and 126 amino acid residues, respectively) to bind to the receptor FhuA. Only the shortest TonB fragment, TonB-77, could not effectively interact with FhuA. We have also observed that the fragments TonB-77 and TonB-86 form homodimers in solution, whereas the longer fragments remain monomeric. TonB fragments that bind to FhuA in vitro also inhibit ferrichrome uptake via FhuA in vivo and protect cells against attack by bacteriophage Phi80.

---

Organizational Affiliation: 

Fakultaet fuer Biologie, Universitaet Konstanz, Germany.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
TonB protein	A	76	Escherichia coli	Mutation(s): 0  Gene Names: tonB
UniProt
Find proteins for P02929 (Escherichia coli (strain K12)) Explore P02929  Go to UniProtKB:  P02929

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.70 Å
• R-Value Free: 0.271 
• R-Value Work: 0.267 
• Space Group: P 6₄ 2 2

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 61.58	α = 90
b = 61.58	β = 90
c = 121.95	γ = 120

Software Package:

Software Name	Purpose
XDS	data scaling
XDS	data reduction
MOLREP	phasing
REFMAC	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2003-09-09 
• Released Date: 2004-04-06 
Deposition Author(s): Koedding, J., Howard, P., Kaufmann, L., Polzer, P., Lustig, A., Welte, W.

Revision History  

• Version 1.0: 2004-04-06
  Type: Initial release
  
• Version 1.1: 2008-04-29
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Derived calculations, Version format compliance