Differential substrate-induced signaling through the TonB-dependent transporter BtuB
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چکیده
منابع مشابه
Differential substrate-induced signaling through the TonB-dependent transporter BtuB.
The BtuB transporter mediates high-affinity binding and TonB-dependent active transport of vitamin B12 [cyanocobalamin (CNCbl)] across the outer membrane of Escherichia coli. A characteristic feature of TonB-dependent transporters is the Ton box, a conserved sequence near the N terminus and exposed to the periplasm. Crosslinking to TonB and site-directed spin labeling indicated that the Ton box...
متن کاملAllosteric Signaling Is Bidirectional in an Outer-Membrane Transport Protein.
In BtuB, the Escherichia coli TonB-dependent transporter for vitamin B12, substrate binding to the extracellular surface unfolds a conserved energy coupling motif termed the Ton box into the periplasm. This transmembrane signaling event facilitates an interaction between BtuB and the inner-membrane protein TonB. In this study, continuous-wave and pulse electron paramagnetic resonance in a nativ...
متن کاملSubstrate-dependent transmembrane signaling in TonB-dependent transporters is not conserved.
Site-directed spin labeling (SDSL) was used to examine and compare transmembrane signaling events in the bacterial outer-membrane transport proteins BtuB, FecA, and FhuA. These proteins extract energy for transport by coupling to the transperiplasmic protein TonB, an interaction that is thought to be mediated by the Ton box, a highly conserved energy-coupling motif in these transporters. In the...
متن کاملSite-directed disulfide bonding reveals an interaction site between energy-coupling protein TonB and BtuB, the outer membrane cobalamin transporter.
Transport of vitamin B(12) across the outer membrane of Escherichia coli, like that of iron-siderophore complexes, is an active transport process requiring a specific outer membrane transporter BtuB, the proton motive force, and the trans-periplasmic energy coupling protein TonB. Interaction between TonB and two of the TonB-dependent siderophore transporters has been detected previously by form...
متن کاملGating of TonB-dependent transporters by substrate-specific forced remodelling
Membrane proteins play vital roles in inside-out and outside-in signal transduction by responding to inputs that include mechanical stimuli. Mechanical gating may be mediated by the membrane or by protein(s) but evidence for the latter is scarce. Here we use force spectroscopy, protein engineering and bacterial growth assays to investigate the effects of force on complexes formed between TonB a...
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ژورنال
عنوان ژورنال: Proceedings of the National Academy of Sciences
سال: 2003
ISSN: 0027-8424,1091-6490
DOI: 10.1073/pnas.1932538100