Conformational dynamics of the ABC transporter McjD seen by single-molecule FRET
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Published version
Author(s)
Type
Journal Article
Abstract
ABC transporters utilize ATP for export processes to provide cellular resistance against toxins, antibiotics, and harmful metabolites in eukaryotes and prokaryotes. Based on static structure snapshots, it is believed that they use an alternating access mechanism, which couples conformational changes to ATP binding (outward‐open conformation) and hydrolysis (inward‐open) for unidirectional transport driven by ATP. Here, we analyzed the conformational states and dynamics of the antibacterial peptide exporter McjD from Escherichia coli using single‐molecule Förster resonance energy transfer (smFRET). For the first time, we established smFRET for an ABC exporter in a native‐like lipid environment and directly monitor conformational dynamics in both the transmembrane‐ (TMD) and nucleotide‐binding domains (NBD). With this, we unravel the ligand dependences that drive conformational changes in both domains. Furthermore, we observe intrinsic conformational dynamics in the absence of ATP and ligand in the NBDs. ATP binding and hydrolysis on the other hand can be observed via NBD conformational dynamics. We believe that the progress made here in combination with future studies will facilitate full understanding of ABC transport cycles.
Date Issued
2018-11-02
Date Acceptance
2018-09-05
Citation
EMBO Journal, 2018, 37 (21)
ISSN
0261-4189
Publisher
EMBO Press
Journal / Book Title
EMBO Journal
Volume
37
Issue
21
Copyright Statement
© 2018 The Authors. Published under the terms of the CC BY 4.0 license. This is an open access article under the terms of the Creative Commons Attribution 4.0 License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Sponsor
Medical Research Council (MRC)
Grant Number
MR/N020103/1
Subjects
ABC transporter
FRET
conformational dynamics
single‐molecule studies
06 Biological Sciences
08 Information And Computing Sciences
11 Medical And Health Sciences
Developmental Biology
Publication Status
Published
Article Number
e100056