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

• Florence Husada ^[1] ; Kiran Bountra ^[2] ; Konstantinos Tassis ^[1] ; Marijn de Boer ^[1] ; Maria Romano ^[2] ; Sylvie Rebuffat ^[3] ; Konstantinos Beis ^[2] ; Thorben Cordes ^[4]
  1. [1] 1 Molecular Microscopy Research Group Zernike Institute for Advanced Materials University of Groningen Groningen The Netherlands
  2. [2] 2 Department of Life Sciences Imperial College London London UK; 3 Rutherford Appleton Laboratory Research Complex at Harwell Didcot UK
  3. [3] 4 Communication Molecules and Adaptation of Microorganisms Laboratory, (MCAM, UMR 7245 CNRS‐MNHN) Muséum National d'Histoire Naturelle Centre National de la Recherche Scientifique Sorbonne Universités Paris France
  4. [4] 1 Molecular Microscopy Research Group Zernike Institute for Advanced Materials University of Groningen Groningen The Netherlands; 5 Physical and Synthetic Biology Faculty of Biology Ludwig‐Maximilians‐Universität München Planegg‐Martinsried Germany

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• Localización: EMBO journal: European Molecular Biology Organization, ISSN 0261-4189, Vol. 37, Nº. 21, 2018, pág. 1
• Idioma: inglés
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  • 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.