Type of Publication: | Journal article |
Publication status: | Published |
Author: | Anselmi, Claudio; Zhou, Wenchang; Diederichs, Kay; Pos, Klaas M.; Faraldo-Gómez, José D. |
Year of publication: | 2011 |
Published in: | Biophysical Journal ; 100 (2011), 3. - pp. 412a. - ISSN 0006-3495. - eISSN 1542-0086 |
DOI (citable link): | https://dx.doi.org/10.1016/j.bpj.2010.12.2442 |
Summary: |
The AcrA/AcrB/TolC multidrug efflux pump confers Escherichia coli with antibiotic
resistance by sequestering toxic compounds found within the periplasm
and inner membrane and extruding them into the extracellular space. The AcrB
trimer is the central component of this efflux complex; anchored in the inner
membrane, it forms an asymmetric assembly that undergoes a conformational
cycle in which each protomer adopts three different structures. As a result, substrates
bound in the periplasmic domain of AcrB are projected into the TolC
channel, which reaches beyond the outer membrane. Crucially, the conformational
cycle within AcrB is driven by the translocation of protons down the gradient
sustained by the inner membrane, through a mechanism that has not been
characterized so far.
Here, we investigate this microscopic mechanism through atomistic freeenergy
molecular dynamics simulations and electrostatic calculations, based
upon novel high-resolution structural data for wild-type and mutagenized
AcrB. Specifically, we assess the events associated with binding and release
of protons within the membrane domain, and determine the mechanism by
which these events are coupled to the reorganization of key transmembrane helices
within each protomer. This investigation reveals how proton translocation
influences both local and remote interactions within the protein, thereby modulating
its structure.
|
Subject (DDC): | 570 Biosciences, Biology |
Bibliography of Konstanz: | Yes |
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ANSELMI, Claudio, Wenchang ZHOU, Kay DIEDERICHS, Klaas M. POS, José D. FARALDO-GÓMEZ, 2011. On How the Conformational Cycle of the AcrB Efflux Pump is Coupled to Proton Translocation : a Theoretical Study Based on High-Resolution Structural Data. In: Biophysical Journal. 100(3), pp. 412a. ISSN 0006-3495. eISSN 1542-0086. Available under: doi: 10.1016/j.bpj.2010.12.2442
@article{Anselmi2011-02Confo-38196, title={On How the Conformational Cycle of the AcrB Efflux Pump is Coupled to Proton Translocation : a Theoretical Study Based on High-Resolution Structural Data}, year={2011}, doi={10.1016/j.bpj.2010.12.2442}, number={3}, volume={100}, issn={0006-3495}, journal={Biophysical Journal}, author={Anselmi, Claudio and Zhou, Wenchang and Diederichs, Kay and Pos, Klaas M. and Faraldo-Gómez, José D.} }