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An ABC transporter with a secondary-active multidrug translocator domain


Multidrug resistance, by which cells become resistant to multiple unrelated pharmaceuticals, is due to the extrusion of drugs from the cell's interior by active transporters such as the human multidrug resistance P-glycoprotein1. Two major classes of transporters mediate this extrusion2,3. Primary-active transporters are dependent on ATP hydrolysis, whereas secondary-active transporters are driven by electrochemical ion gradients that exist across the plasma membrane. The ATP-binding cassette (ABC) transporter LmrA4 is a primary drug transporter in Lactococcus lactis that can functionally substitute for P-glycoprotein in lung fibroblast cells5. Here we have engineered a truncated LmrA protein that lacks the ATP-binding domain. Surprisingly, this truncated protein mediates a proton–ethidium symport reaction without the requirement for ATP. In other words, it functions as a secondary-active multidrug uptake system. These findings suggest that the evolutionary precursor of LmrA was a secondary-active substrate translocator that acquired an ATP-binding domain to enable primary-active multidrug efflux in L. lactis.

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Figure 1: Structural properties of LmrA are maintained in LmrA-MD.
Figure 2: LmrA-MD mediates multidrug uptake in L. lactis.
Figure 3: Ethidium transport by LmrA-MD is coupled to Δp.
Figure 4: Coupled efflux of ethidium and protons by LmrA in L. lactis cells.


  1. Ambudkar, S. V. et al. Biochemical, cellular and pharmacological aspects of the multidrug transporter. Annu. Rev. Pharmacol. Toxicol. 39, 361–398 (1999)

    Article  CAS  Google Scholar 

  2. Higgins, C. F. ABC transporters: from microorganisms to man. Annu. Rev. Cell Biol. 8, 67–113 (1992)

    Article  CAS  Google Scholar 

  3. Paulsen, I. T., Brown, M. H. & Skurray, R. A. Proton-dependent multidrug efflux systems. Microbiol. Rev. 60, 575–608 (1996)

    CAS  PubMed  PubMed Central  Google Scholar 

  4. Van Veen, H. W. et al. Multidrug resistance mediated by a bacterial homolog of the human drug transporter MDR1. Proc. Natl Acad. Sci. USA 93, 10668–10672 (1996)

    Article  ADS  CAS  Google Scholar 

  5. Van Veen, H. W. et al. A bacterial antibiotic-resistance gene that complements the human multidrug-resistance P-glycoprotein gene. Nature 391, 291–295 (1998)

    Article  ADS  CAS  Google Scholar 

  6. Van Veen, H. W. et al. The homodimeric ATP-binding cassette transporter LmrA mediates multidrug transport by an alternating two-site (two-cylinder engine) mechanism. EMBO J. 19, 2503–2514 (2000)

    Article  CAS  Google Scholar 

  7. Chang, G. & Roth, C. B. The structure of MsbA from E. coli: a homolog of the multidrug resistance ATP binding cassette (ABC) transporters. Science 293, 1793–1800 (2001)

    Article  ADS  CAS  Google Scholar 

  8. Chang, G. Structure of MsbA from Vibrio cholera: a multidrug resistance ABC transporter homolog in a closed conformation. J. Mol. Biol. 330, 419–430 (2003)

    Article  CAS  Google Scholar 

  9. Putman, M., Van Veen, H. W., Degener, J. E. & Konings, W. N. Antibiotic resistance: era of the multidrug pump. Mol. Microbiol. 36, 772–774 (2000)

    Article  CAS  Google Scholar 

  10. Kaback, H. R. in The Bacteria Vol. 12 (Bacterial Energetics) (ed. Krulwich, T. A.) 151–193 (Academic, London, 1990)

    Book  Google Scholar 

  11. Sharom, F. J., Yu, X. & Doige, C. A. Functional reconstitution of drug transport and ATPase activity in proteoliposomes containing partially purified P-glycoprotein. J. Biol. Chem. 268, 24197–24202 (1993)

    CAS  PubMed  Google Scholar 

  12. Eytan, G. D., Regev, R. & Assaraf, Y. G. Functional reconstitution of P-glycoprotein reveals an apparent near stoichiometric drug transport to ATP hydrolysis. J. Biol. Chem. 271, 3172–3178 (1996)

    Article  CAS  Google Scholar 

  13. Booth, I. R. Regulation of cytoplasmic pH in bacteria. Microbiol. Rev. 49, 359–378 (1985)

    CAS  PubMed  PubMed Central  Google Scholar 

  14. Kroll, R. G. & Booth, I. R. The relationship between intracellular pH, the pH gradient and potassium-transport in Escherichia coli. Biochem. J. 216, 709–716 (1983)

    Article  CAS  Google Scholar 

  15. Bakker, E. P. Alkali Cation Transport Systems in Prokaryotes (CRC Press, Florida, 1993)

    Google Scholar 

  16. Thiebaut, F. et al. Activity of the multidrug transporter results in alkalinization of the cytosol: measurement of cytosolic pH by microinjection of a pH-sensitive dye. J. Histochem. Cytochem. 38, 685–690 (1990)

    Article  CAS  Google Scholar 

  17. Landwojtowicz, E., Nervi, P. & Seelig, A. Real-time monitoring of P-glycoprotein activation in living cells. Biochemistry 41, 8050–8057 (2002)

    Article  CAS  Google Scholar 

  18. Santai, C. T., Fritz, F. & Roepe, P. D. Effects of ion gradients on H+transport mediated by human MDR1 protein. Biochemistry 38, 4227–4234 (1999)

    Article  CAS  Google Scholar 

  19. Howard, E. M. & Roepe, P. D. Purified human MDR1 modulates membrane potential in reconstituted proteoliposomes. Biochemistry 42, 3544–3555 (2003)

    Article  CAS  Google Scholar 

  20. Kuroda, M., Dey, S., Sanders, O. I. & Rosen, B. P. Alternate energy coupling of ArsB, the membrane subunit of the Ars anion-translocating ATPase. J. Biol. Chem. 272, 326–331 (1997)

    Article  CAS  Google Scholar 

  21. Margolles, A., Putman, M., Van Veen, H. W. & Konings, W. N. The purified and functionally reconstituted multidrug transporter LmrA of Lactococcus lactis mediates the transbilayer movement of specific fluorescent phospholipids. Biochemistry 38, 16298–16306 (1999)

    Article  CAS  Google Scholar 

  22. Reuter, G. et al. The ATP-binding cassette multidrug transporter LmrA and lipid transporter MsbA have overlapping substrate specificities. J. Biol. Chem. 278, 35193–35198 (2003)

    Article  CAS  Google Scholar 

  23. Janvilisri, T. et al. Sterol transport by the human breast cancer resistance protein (ABCG2) expressed in Lactococcus lactis. J. Biol. Chem. 278, 20645–20651 (2003)

    Article  CAS  Google Scholar 

  24. Breeuwer, P., Drocourt, J., Rombouts, F. M. & Abee, T. A novel method for continuous determination of the intracellular pH in bacteria with the internally conjugated fluorescent probe 5 (and 6-)-carboxyfluorescein succinimidyl ester. Appl. Environ. Microbiol. 62, 178–183 (1996)

    CAS  PubMed  PubMed Central  Google Scholar 

  25. Novo, D., Perlmutter, N. G., Hunt, R. H. & Shapiro, H. M. Accurate flow cytometric membrane potential measurement in bacteria using diethyloxacarbocyanine and a ratiometric technique. Cytometry 35, 55–63 (1999)

    Article  CAS  Google Scholar 

  26. Van Veen, H. W., Abee, T., Kortstee, G. J. J., Konings, W. N. & Zehnder, A. J. B. Mechanism and energetics of the secondary phosphate transport system of Acinetobacter johnsonii 210A. J. Biol. Chem. 268, 19377–19383 (1993)

    CAS  PubMed  Google Scholar 

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We thank Chris Higgins, Peter McNaughton, Ben Luisi, and Ian Booth for stimulating discussions. This research was funded by Cancer Research UK, the Association of International Cancer Research (AICR), the Biotechnology and Biological Sciences Research Council (BBSRC), the Medical Research Council (MRC), the Royal Society, and Molecular Devices Ltd. S.V. was the recipient of a Cambridge Nehru Scholarship.

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Correspondence to Hendrik W. van Veen.

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Venter, H., Shilling, R., Velamakanni, S. et al. An ABC transporter with a secondary-active multidrug translocator domain. Nature 426, 866–870 (2003).

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