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PROSITE documentation PDOC00354 [for PROSITE entry PS01156] |
In Escherichia coli the tonB protein interacts with outer membrane receptor proteins that carry out high-affinity binding and energy-dependent uptake of specific substrates into the periplasmic space. These substrates are either poorly permeable through the porin channels or are encountered at very low concentrations. In the absence of tonB these receptors bind their substrates but do not carry out active transport. The tonB protein also interacts with some colicins. The proteins that are currently known or presumed to interact with tonB are:
Gene Function or name ---- ------------------------------------------------------------------- btuB Receptor for cobalamin. cirA Receptor for colicin I (exact substrate not known). fatA Receptor for ferric anguibactin (Vibrio anguillarum). fcuA Receptor for ferrichrome (Yersinia enterocolitica). fecA Receptor for iron dicitrate. fepA Receptor for ferrienterobactin (ferric enterochelin). fhuA Receptor for ferrichrome-iron. fhuE Receptor for ferric coprogen, ferrioxamine B, and rhodotrulic acid. foxA Receptor for ferrioxamine (Yersinia enterocolitica). fptA Receptor for Fe(III)-pyochelin (Pseudomonas aeruginosa). fpvA Receptor for ferripyoverdine (Pseudomonas aeruginosa). fyuA Receptor for pesticin and yersiniabactin (Yersinia). hemR Receptor for hemin (Yersinia enterocolitica). hxuC Receptor for heme/hemopexin (Haemophilus influenzae). irgA Receptor for ferric vibriobactin (Vibrio cholerae). iroA Receptor for a siderophore (Neisseria meningitidis). iutA Receptor for ferric aerobactin. pbuA Receptor for ferric pseudobactin M114 (Pseudomonas strain M114). pfeA Receptor for ferric enterobactin (Pseudomonas aeruginosa). pupA Receptor for ferric pseudobactin 358 (Pseudomonas putida). pupB Receptor for ferric pseudobactin BN7 and BN8 (Pseudomonas putida). tbp1 Receptor for transferrin (Neisseria and Haemophilus). Haemophilus influenzae hypothetical proteins HI0262, HI0661, HI0635, HI0712, HI1217, and HI1567. cba Colicin B, a channel forming colicin. cda Colicin D. cma Colicin M, inhibitor of murein biosynthesis.
Most of these proteins contain, at their N-terminus, a short conserved region [1,2,3], called the tonB-box, involved in the interaction of the protein with the tonB protein [4]. With the exception of the colicin B, D and M receptors they all also contain, in their C-terminal extremity a short conserved domain that contains two invariant residues.
Last update:December 2004 / Pattern and text revised.
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PROSITE methods (with tools and information) covered by this documentation:
1 | Authors | Lundrigan M.D. Kadner R.J. |
Title | Nucleotide sequence of the gene for the ferrienterochelin receptor FepA in Escherichia coli. Homology among outer membrane receptors that interact with TonB. | |
Source | J. Biol. Chem. 261:10797-10801(1986). | |
PubMed ID | 3015941 |
2 | Authors | Schramm E. Mende J. Braun V. Kamp R.M. |
Title | Nucleotide sequence of the colicin B activity gene cba: consensus pentapeptide among TonB-dependent colicins and receptors. | |
Source | J. Bacteriol. 169:3350-3357(1987). | |
PubMed ID | 2439491 |
3 | Authors | Nau C.D. Konisky J. |
Title | Evolutionary relationship between the TonB-dependent outer membrane transport proteins: nucleotide and amino acid sequences of the Escherichia coli colicin I receptor gene. | |
Source | J. Bacteriol. 171:1041-1047(1989). | |
PubMed ID | 2644220 |
4 | Authors | Gudmundsdottir A. Bell P.E. Lundrigan M.D. Bradbeer C. Kadner R.J. |
Title | Point mutations in a conserved region (TonB box) of Escherichia coli outer membrane protein BtuB affect vitamin B12 transport. | |
Source | J. Bacteriol. 171:6526-6533(1989). | |
PubMed ID | 2687240 |