Molecular basis for multidrug efflux by an anaerobic-associated RND transporter
Bacteria can resist antibiotics and toxic substances within demanding ecological settings, such as low oxygen, extreme acid, and during nutrient starvation. MdtEF, a proton motive force-driven efflux pump from the resistance-nodulation-cell division (RND) superfamily, is upregulated in these conditions but its molecular mechanism is unknown. Here, we report cryo-electron microscopy structures of Escherichia coli multidrug transporter MdtF within native-lipid nanodiscs, including a single-point mutant with an altered multidrug phenotype and associated substrate-bound form. Drug binding domain and channel conformational plasticity likely governs substrate polyspecificity, analogous to closely related, constitutively expressed counterpart, AcrB. Whereas we discover distinct transmembrane state transitions within MdtF, which create a more engaged proton relay network, altered drug transport allostery and an acid-responsive increase in efflux efficiency. Our findings provide mechanistic insights necessary to understand bacterial xenobiotic and toxin removal by MdtF and its role within nutrient-depleted and acid stress settings, as endured in the gastrointestinal tract.
Authors
- Mohd Athar (ORCID: https://orcid.org/0000-0001-6337-1026)
- C. W. Keevil (ORCID: https://orcid.org/0000-0003-1917-7706)
- Attilio Vittorio Vargiu (ORCID: https://orcid.org/0000-0003-4013-8867)
- Christopher Adams (ORCID: https://orcid.org/0000-0003-1959-7217)
- Oliver Durrant (ORCID: https://orcid.org/0000-0003-3183-7025)
- Eamonn Reading (ORCID: https://orcid.org/0000-0001-8219-0052)
- Nisha Patel (ORCID: https://orcid.org/0000-0002-5809-8683)
- Helen I. Zgurskaya (ORCID: https://orcid.org/0000-0001-8929-4727)
- Christine E. Prosser
- Zainab Ahdash (ORCID: https://orcid.org/0000-0002-4495-8689)
- Muhammad Ramiz Uddin (ORCID: https://orcid.org/0000-0002-2337-7383)
- Joana S. Sousa (ORCID: https://orcid.org/0000-0001-5325-060X)
- Ryan Lawrence (ORCID: https://orcid.org/0000-0003-1232-3627)
- David McMillan (ORCID: https://orcid.org/0000-0001-9376-0284)
- L. Sutton
- Sophie Lellman (ORCID: https://orcid.org/0000-0002-1208-8260)
Institutions
- King's College London (GB)
- Istituto Nazionale di Fisica Nucleare, Sezione di Cagliari (IT)
- UCB Pharma (United Kingdom) (GB)
- Biopharma Technology (United Kingdom) (GB)
- University of Southampton (GB)
- University of Oklahoma (US)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-12-03
- DOI
- https://doi.org/10.1038/s41467-025-65565-7
- Primary Topic
- Bacterial Genetics and Biotechnology
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- University of Oklahoma
- Università degli Studi di Cagliari
- UK Research and Innovation
- University of Southampton
- King's College London
- National Institutes of Health
- Biotechnology and Biological Sciences Research Council
- National Institute of Allergy and Infectious Diseases
- UCB Pharma