1IHR

Crystal structure of the dimeric C-terminal domain of TonB

Summary for 1IHR

• Entry DOI: 10.2210/pdb1ihr/pdb
• Descriptor: TonB protein, BROMIDE ION (3 entities in total)
• Functional Keywords: novel fold, intertwined dimer, protein transport
• Biological source: Escherichia coli
• Cellular location: Cell inner membrane; Single-pass membrane protein; Periplasmic side: P02929
• Total number of polymer chains: 2
• Total formula weight: 17447.40

Authors

Chang, C.,Mooser, A.,Pluckthun, A.,Wlodawer, A. (deposition date: 2001-04-20, release date: 2001-08-01, Last modification date: 2024-02-07)

Primary citation

Chang, C.,Mooser, A.,Pluckthun, A.,Wlodawer, A.
Crystal structure of the dimeric C-terminal domain of TonB reveals a novel fold.
J.Biol.Chem., 276:27535-27540, 2001

PubMed Abstract: The TonB-dependent complex of Gram-negative bacteria couples the inner membrane proton motive force to the active transport of iron.siderophore and vitamin B(12) across the outer membrane. The structural basis of that process has not been described so far in full detail. The crystal structure of the C-terminal domain of TonB from Escherichia coli has now been solved by multiwavelength anomalous diffraction and refined at 1.55-A resolution, providing the first evidence that this region of TonB (residues 164-239) dimerizes. Moreover, the structure shows a novel architecture that has no structural homologs among any known proteins. The dimer of the C-terminal domain of TonB is cylinder-shaped with a length of 65 A and a diameter of 25 A. Each monomer contains three beta strands and a single alpha helix. The two monomers are intertwined with each other, and all six beta-strands of the dimer make a large antiparallel beta-sheet. We propose a plausible model of binding of TonB to FhuA and FepA, two TonB-dependent outer-membrane receptors.

PubMed: 11328822
DOI: 10.1074/jbc.M102778200

Experimental method

X-RAY DIFFRACTION (1.55 Å)