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Showing 1 to 15 of 15 for “"TonB"”.
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Studies of the structure, evolution, and TonB-dependence of the colicin I receptor of Escherichia coli
The colicin I receptor (Cir) is an outer membrane protein, the expression of which is iron regulated. The DNA downstream of the cloned cir gene, when expressed in a maxicell system, encoded a protein of molecular weight 32,000. The expression of this protein was determined to be directed toward the …
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Characterization of the Burkholderia mallei ∆tonB Mutant and its Potential as a Backbone Attenuated Strain for Vaccine Development
In this study, a Burkholderia mallei ∆tonB mutant deficient in iron acquisition was constructed, characterized and evaluated for its protective properties in acute inhalational mouse models of glanders and melioidosis infection. Compared to wild type, the B. mallei ΔtonB exhibits slower growth …
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Characterization of FhuA 104/149C: a Double Cysteine FhuA Mutant with Normal Binding and Diminished Transport
… by an N-terminal plug domain. The cell membrane TonB/ExbB/ExbD complex presumably supplies energy via interaction between the FhuA N-terminal TonB box and the C-terminal domain of TonB. In order to better understand the mechanism of action the FhuA mutant 104/149C, tethering the central β-strands …
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Mechanisms of Iron Acquisition Employed by Neisseria Gonorrhoeae for Survival within Cervical Epithelial Cells
… energy-harnessing cytoplasmic membrane protein, TonB, as well as specific outer membrane TonB-dependent transporters (TdTs). The overall goal of this study was to investigate the extra- and intracellular iron acquisition mechanisms of N. gonorrhoeae and determine the role of the TonB and TdTs in …
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Interaction of Colicin Ia With Escherichia Coli: I. Mechanisms of Colicin Insensitivity. Ii. Inhibition of Colicin Binding by Phenolic Uncouplers
… coli were examined. Although whole cells of TonB strains are insensitive to colicin Ia, cytoplasmic membrane vesicles prepared from a TonB strain are sensitive to colicin-induced membrane depolarization. This finding shows that the TonB function is not required for channel formation and …
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Investigating Iron Transport and Utilization Features of Acinetobacter baumannii
… three gene loci encoding functions in the TonB energy-transducing complex to provide the energy needed for iron transport. Transformation of <i>Escherichia coli</i> KP1344 with plasmids harboring the TonB components of these <i>A. baumannii</i> TonB systems promoted cell growth under …
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Decomposition of Proteins into Functionally and Evolutionarily Independent Cooperative Units
… were used to analyze two protein families - the TonB dependent receptors and the S1A serine proteases. The TonB dependent receptor family members are membrane bound siderophore transporters. Ligand binding on the extracellular side of the transporter transmits a signal to the periplasmic side …
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Hemin Acquisition in Bartonella quintana
… in <i>E. coli </i>EB53 and was shown to be TonB-dependent using an isogenic <i>E. coli hemA tonB</i> strain.</p> <p>Fur (ferric uptake regulator) has been described as a global iron-responsive regulator in &gamma-proteobacteria. If expression is forced, <i>B. quintana fur</i> is able to …
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Hemin Acquisition in Bartonella quintana
… in <i>E. coli </i>EB53 and was shown to be TonB-dependent using an isogenic <i>E. coli hemA tonB</i> strain.</p> <p>Fur (ferric uptake regulator) has been described as a global iron-responsive regulator in &gamma-proteobacteria. If expression is forced, <i>B. quintana fur</i> is able to …
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Genetic and biochemical analysis of the colicin I receptor gene of Escherichia coli: Structural organization and transcriptional control mechanisms
… sequence which closely resembled that of other TonB-dependent proteins.
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<i>Haemophilus influenzae</i> modulins in chronic obstructive pulmonary disease airway inflammation
… Further analysis of four proteins, ClpB, OmpP2, TonB, and RelA, suggested a potential role in the IL-8 response. A fifth protein, FtsH, showed no such response. Study of the other 22 proteins is required to understand their role in cytokine induction. These results suggest that factors other than …
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Transferrin binding protein B structure, function, and export in Neisseria gonorrhoeae
… binding proteins: TbpA and TbpB. TbpA is a TonB-dependent, outer membrane transporter and TbpB is a bilobed, surface exposed lipoprotein. TbpB can distinguish between apo- and holo-transferrin which is involved in increasing the efficiency of iron uptake through the Tbps. It is anchored in …
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Construction, characterization, and evaluation of CLH001 as a vaccine candidate against respiratory glanders
… we constructed and characterized B. mallei ∆tonB ∆hcp1 (CLH001), a strain deficient in iron uptake and type six secretion functions, and investigated its ability to protect against acute respiratory glanders infection. When compared to wild-type (wt), CLH001 exhibited decreased growth …
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Iron and Manganese Homeostasis in Marine Bacteria
… most of the known Fe uptake systems, including TonB and outer‐membrane receptors, but has a predicted, but incomplete iron uptake ABC‐class transporter operon, whose expression is much enhanced in Fe‐depleted conditions, although a strain lacking these genes was unaffected in growth. The …
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Thermodynamic Investigations of Metalloproteins: Metal as Probe and Protein as Probe
… can deferrate Tf without energy supplied from TonB, resulting in sequestration by apo-FbpA.</p> <p>In Chapter 5, we extend our investigation of the <italic>N. gonorrhoeae</italic> iron uptake system by using the metal as the probe in one case and the protein as the probe in another case. TbpA, …