Research data supporting “Relocation of active site carboxylates in major facilitator superfamily multidrug transporter LmrP reveals plasticity in proton interactions”
Nair, Asha V.
University of Cambridge
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Nair, A. V., Singh, H., Raturi, S., Neuberger, A., Tong, Z., Ding, N., Agboh, K., & et al. (2016). Research data supporting “Relocation of active site carboxylates in major facilitator superfamily multidrug transporter LmrP reveals plasticity in proton interactions” [Dataset]. https://doi.org/10.17863/CAM.6219
The expression of polyspecific membrane transporters is one important mechanism by which cells can obtain resistance to structurally different antibiotics and cytotoxic agents. These transporters reduce intracellular drug concentrations to subtoxic levels by mediating drug efflux across the cell envelope. The major facilitator superfamily multidrug transporter LmrP from Lactococcus lactis catalyses drug efflux in a membrane potential and chemical proton gradient-dependent fashion. To enable the interaction with protons and cationic substrates, LmrP contains catalytic carboxyl residues on the surface of a large interior chamber that is formed by transmembrane helices. These residues co-localise together with polar and aromatic residues, and are predicted to be present in two clusters. To investigate the functional role of the catalytic carboxylates, we generated mutant proteins catalysing membrane potential-independent dye efflux by removing one of the carboxyl residues in Cluster 1. We then relocated this carboxyl residue to six positions on the surface of the interior chamber, and tested for restoration of wildtype energetics. The reinsertion at positions towards Cluster 2 reinstated the membrane potential dependence of dye efflux. Our data uncover a remarkable plasticity in proton interactions in LmrP, which is a consequence of the flexibility in the location of key residues that are responsible for proton/multidrug antiport. This repository contains the data sets that were used to prepare the figures.
A previous version of this manuscript and these data was withdrawn by the authors from publication in the Journal of Biological Chemistry (jbc.M115.694901). The figures in the current publication in Scientific Reports are based on new and original data which were generated in triplicate or more, and which are archived in this data repository.
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energetics, enzyme mechanism, membrane protein, membrane transport, multidrug transporter, LmrP, drug/proton antiport, ligand binding, major facilitator superfamily
Publication Reference: https://doi.org/10.1038/srep38052
This record's DOI: https://doi.org/10.17863/CAM.6219
Attribution 4.0 International
Licence URL: http://creativecommons.org/licenses/by/4.0/
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