Cytoplasmic membrane protonmotive force energizes periplasmic interactions between ExbD and TonB
نویسندگان
چکیده
منابع مشابه
The same periplasmic ExbD residues mediate in vivo interactions between ExbD homodimers and ExbD-TonB heterodimers.
The TonB system couples cytoplasmic membrane proton motive force to TonB-gated outer membrane transporters for active transport of nutrients into the periplasm. In Escherichia coli, cytoplasmic membrane proteins ExbB and ExbD promote conformational changes in TonB, which transmits this energy to the transporters. The only known energy-dependent interaction occurs between the periplasmic domains...
متن کاملThe ExbD periplasmic domain contains distinct functional regions for two stages in TonB energization.
The TonB system of gram-negative bacteria energizes the active transport of diverse nutrients through high-affinity TonB-gated outer membrane transporters using energy derived from the cytoplasmic membrane proton motive force. Cytoplasmic membrane proteins ExbB and ExbD harness the proton gradient to energize TonB, which directly contacts and transmits this energy to ligand-loaded transporters....
متن کاملIdentification of functionally important TonB-ExbD periplasmic domain interactions in vivo.
In gram-negative bacteria, the cytoplasmic membrane proton-motive force energizes the active transport of TonB-dependent ligands through outer membrane TonB-gated transporters. In Escherichia coli, cytoplasmic membrane proteins ExbB and ExbD couple the proton-motive force to conformational changes in TonB, which are hypothesized to form the basis of energy transduction through direct contact wi...
متن کاملThe TonB Dimeric Crystal Structures Do Not Exist In Vivo
The TonB system energizes transport of nutrients across the outer membrane of Escherichia coli using cytoplasmic membrane proton motive force (PMF) for energy. Integral cytoplasmic membrane proteins ExbB and ExbD appear to harvest PMF and transduce it to TonB. The carboxy terminus of TonB then physically interacts with outer membrane transporters to allow translocation of ligands into the perip...
متن کاملExbB protein in the cytoplasmic membrane of Escherichia coli forms a stable oligomer.
In Gram-negative bacteria like Escherichia coli the ExbB-ExbD-TonB protein complex is anchored to the cytoplasmic membrane and is involved in energization of outer membrane transport. Outer membrane proteins catalyze energy-coupled transport of scarce nutrients. Energy is derived from the protonmotive force of the cytoplasmic membrane which is transferred through ExbB-ExbD-TonB to the outer mem...
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ژورنال
عنوان ژورنال: Molecular Microbiology
سال: 2009
ISSN: 0950-382X,1365-2958
DOI: 10.1111/j.1365-2958.2009.06785.x