Conformational dynamics of the ABC transporter McjD seen by single-molecule FRET

Florence Husada, Kiran Bountra, Konstantinos Tassis, Marijn de Boer, Maria Romano, Sylvie Rebuffat, Konstantinos Beis, Thorben Cordes

Research output: Contribution to journalArticleAcademicpeer-review

27 Citations (Scopus)
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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 Forster 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.

Original languageEnglish
Article number100056
Number of pages13
JournalEMBO Journal
Volume37
Issue number21
DOIs
Publication statusPublished - 2-Nov-2018

Keywords

  • ABC transporter
  • conformational dynamics
  • FRET
  • single-molecule studies
  • STRUCTURAL BASIS
  • CRYSTAL-STRUCTURE
  • BINDING DOMAINS
  • MSBA
  • MECHANISM
  • HOMOLOG
  • FLUORESCENCE
  • SPECTROSCOPY
  • CYCLE

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