TonB protein of Salmonella typhimurium

Hannavy, Kevin; Barr, Gordon; Dorman, Charles J.; Adamson, J G; Mazengera, L.R.; Gallagher, Maurice P.; Evans, James S.; Levine, Barry A.; Trayer, Ian P.; Higgins, Christopher F.

doi:10.1016/s0022-2836(99)80009-6

Cited by 122 publications

(18 citation statements)

References 55 publications

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“…This finding substantiated genetic analyses that suggested interactions between TonB and other outer membrane transporters, namely the ferrichrome-iron receptor FhuA (18,19) and the vitamin B 12 receptor BtuB (20 -22). However, formation of the FepA-TonB complex appeared to be independent of the presence of ferric enterobactin, since the strains used carried mutations in the enterobactin biosynthetic genes and were negative on chrome azurol S plates used for detecting siderophore excretion (23).…”

supporting

confidence: 72%

“…2 and 11). TonB homologues have been identified in many Gram-negative bacteria, including Salmonella enterica serovar Typhimurium (12), Yersinia enterocolitica (13), Haemophilus influenzae (14), and Pseudomonas aeruginosa (15). In addition, complexes between TonB or its homologues and other proteins (ExbB, ExbD, and as yet unidentified proteins) were detected with anti-E. coli TonB monoclonal antibodies (mAbs 1 ; Ref.…”

mentioning

confidence: 99%

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Cell Envelope Signaling in Escherichia coli

Moeck

Coulton

Postle

1997

Journal of Biological Chemistry

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The ferrichrome-iron receptor of Escherichia coli is FhuA, an outer membrane protein that is dependent upon the energy-coupling protein TonB to enable active transport of specific hydroxamate siderophores, infection by certain phages, and cell killing by the protein antibiotics colicin M and microcin 25. In vivo cross-linking studies were performed to establish at the biochemical level the interaction between FhuA and TonB. In an E. coli strain in which both proteins were expressed from the chromosome, a high molecular mass complex was detected when the ferrichrome homologue ferricrocin was added immediately prior to addition of crosslinker. The complex included both proteins; it was absent from strains of E. coli that were devoid of either FhuA or TonB, and it was detected with anti-FhuA and anti-TonB monoclonal antibodies. These results indicate that, in vivo, the binding of ferricrocin to FhuA enhances complex formation between the receptor and TonB. An in vitro system was established with which to examine the FhuA-TonB interaction. Incubation of TonB with histidine-tagged FhuA followed by addition of Ni 2؉ -nitrilotriacetate-agarose led to the specific recovery of both TonB and FhuA. Addition of ferricrocin or colicin M to FhuA in this system greatly increased the coupling between FhuA and TonB. Conversely, a monoclonal antibody that binds near the N terminus of FhuA reduced the retention of TonB by histidine-tagged FhuA. These studies demonstrate the significance of ligand binding at the external surface of the cell to mediate signal transduction across the outer membrane.

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confidence: 72%

mentioning

confidence: 99%

Cell Envelope Signaling in Escherichia coli

Moeck

Coulton

Postle

1997

Journal of Biological Chemistry

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“…TonB transduces the energy that is needed for active transport of siderophores and vitamin B 12 through its cognate outer membrane receptors. The low copy number of TonB molecules compared with the number of TonB-dependent receptors (1) suggests that TonB probes many receptors and transduces energy only to ligand-loaded ones. Transport is initiated by binding of the ligand to the receptor binding site with submicromolar affinity.…”

Section: Discussionmentioning

confidence: 99%

“…Most substances are translocated through the outer membrane by diffusion porins using a concentration gradient. However, substances occurring at very low concentrations like iron siderophores and vitamin B 12 use specific, active, high affinity uptake systems that are driven by chemiosmotic energy transduced to the outer membrane by the TonB protein (1). Three-dimensional structures of the following TonBdependent receptors have been determined by x-ray crystallography: FhuA (2, 3), FepA (4), FecA (5), and BtuB (6).…”

mentioning

confidence: 99%

Crystal Structure of a 92-Residue C-terminal Fragment of TonB from Escherichia coli Reveals Significant Conformational Changes Compared to Structures of Smaller TonB Fragments

Ködding

Killig

Polzer

et al. 2005

Journal of Biological Chemistry

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Uptake of siderophores and vitamin B 12 through the outer membrane of Escherichia coli is effected by an active transport system consisting of several outer membrane receptors and a protein complex of the inner membrane. The link between these is TonB, a protein associated with the cytoplasmic membrane, which forms a large periplasmic domain capable of interacting with several outer membrane receptors, e.g.

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“…The majority of identified TonB proteins contain Pro-Glu and Pro-Lys repeat domains in close proximity, upon which we relied for our strategy in cloning tonB Bb . The region encompassing these domains is thought to allow TonB to physically extend through the periplasm, allowing contact with outer-membrane receptors (Evans et al, 1986 ;Hannavy et al, 1990 ;Larsen et al, 1993). The histidine at residue 20 and neighbouring residues conserved among other TonB residues are believed to be important in the E. coli TonB function (Karlsson et al, 1993 ;Jaskula et al, 1994).…”

Section: Discussionmentioning

confidence: 99%

Disruption of tonB in Bordetella bronchiseptica and Bordetella pertussis prevents utilization of ferric siderophores, haemin and haemoglobin as iron sources The GenBank accession number for the sequence reported in this paper is AF087669.

Nicholson

Beall

1999

Microbiology

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The Bordetella bronchiseptica tonB gene was cloned by detection of a chromosomal restriction fragment hybridizing with each of two degenerate oligonucleotides that corresponded to Pro-Glu and Pro-Lys repeats characteristic of known TonB proteins. The tonB Bb gene was situated upstream of exbB and exbD homologues and downstream of a putative Fur-regulated promoter. Hybridization results indicated that the tonB operon and flanking regions were highly conserved between B. bronchiseptica, Bordetella pertussis and Bordetella parapertussis. Disruption of tonB in B. bronchiseptica resulted in inability to grow in iron-limiting media, and inability to utilize alcaligin, enterobactin, ferrichrome, desferroxamine B, haemin and haemoglobin. Although it was not possible to inactivate tonB in a clinical B. pertussis isolate, tonB was disrupted in a laboratory B. pertussis strain previously selected for the ability to grow on Luria-Bertani medium. This B. pertussis tonB mutant shared a similar iron complex utilization deficient phenotype with the B. bronchiseptica tonB mutant. The B. bronchiseptica tonB operon present on a plasmid did not complement an Escherichia coli tonB mutant, but inefficient reconstitution of enterobactin utilization was observed in one fepA mutant harbouring plasmid copies of the B. pertussis fepA homologue and tonB Bb operon.

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TonB protein of Salmonella typhimurium

Cited by 122 publications

References 55 publications

Cell Envelope Signaling in Escherichia coli

Cell Envelope Signaling in Escherichia coli

Crystal Structure of a 92-Residue C-terminal Fragment of TonB from Escherichia coli Reveals Significant Conformational Changes Compared to Structures of Smaller TonB Fragments

Disruption of tonB in Bordetella bronchiseptica and Bordetella pertussis prevents utilization of ferric siderophores, haemin and haemoglobin as iron sources The GenBank accession number for the sequence reported in this paper is AF087669.

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