Multidrug resistance transporter BmrA mutant E504A bound with ATP, Mg, and Rhodamine 6G solved by Cryo-EM

Experimental Data Snapshot

  • Resolution: 4.20 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

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Substrate-bound and substrate-free outward-facing structures of a multidrug ABC exporter.

Chaptal, V.Zampieri, V.Wiseman, B.Orelle, C.Martin, J.Nguyen, K.A.Gobet, A.Di Cesare, M.Magnard, S.Javed, W.Eid, J.Kilburg, A.Peuchmaur, M.Marcoux, J.Monticelli, L.Hogbom, M.Schoehn, G.Jault, J.M.Boumendjel, A.Falson, P.

(2022) Sci Adv 8: eabg9215-eabg9215

  • DOI: https://doi.org/10.1126/sciadv.abg9215
  • Primary Citation of Related Structures:  
    6R72, 6R81, 7BG4, 7OW8

  • PubMed Abstract: 

    Multidrug ABC transporters translocate drugs across membranes by a mechanism for which the molecular features of drug release are so far unknown. Here, we resolved three ATP-Mg 2+ -bound outward-facing conformations of the Bacillus subtilis (homodimeric) BmrA by x-ray crystallography and single-particle cryo-electron microscopy (EM) in detergent solution, one of them with rhodamine 6G (R6G), a substrate exported by BmrA when overexpressed in B. subtilis . Two R6G molecules bind to the drug-binding cavity at the level of the outer leaflet, between transmembrane (TM) helices 1-2 of one monomer and TM5'-6' of the other. They induce a rearrangement of TM1-2, highlighting a local flexibility that we confirmed by hydrogen/deuterium exchange and molecular dynamics simulations. In the absence of R6G, simulations show a fast postrelease occlusion of the cavity driven by hydrophobicity, while when present, R6G can move within the cavity, maintaining it open.

  • Organizational Affiliation

    Drug Resistance and Membrane Proteins Group, Molecular Microbiology and Structural Biochemistry Laboratory, CNRS UMR 5086, University of Lyon, IBCP, 7, passage du Vercors, 69367 Lyon, France.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Lipid A export ATP-binding/permease protein MsbA
A, B
599Bacillus subtilisMutation(s): 1 
Gene Names: B4417_3307
EC: 3.6.3
Membrane Entity: Yes 
Find proteins for O06967 (Bacillus subtilis (strain 168))
Explore O06967 
Go to UniProtKB:  O06967
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO06967
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 4.20 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion

Structure Validation

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Entry History & Funding Information

Deposition Data

Funding OrganizationLocationGrant Number
French National Research AgencyFranceANR-17-CE11-0015-03
Knut and Alice Wallenberg FoundationSweden--
Swedish Research CouncilSweden--

Revision History  (Full details and data files)

  • Version 1.0: 2022-01-12
    Type: Initial release
  • Version 1.1: 2022-02-02
    Changes: Advisory, Database references, Derived calculations