1887

Abstract

Multidrug resistance (MDR) genes are abundant in genomes, and yet these bacteria are generally drug sensitive under routine laboratory conditions, indicating low or no expression of these genes. Drug-resistant mutations have been isolated that lie in regulatory genes adjacent to the MDR genes, suggesting that resistance arises by derepression. This study identified a divergently oriented pair consisting of a TetR-family regulator () and a major facilitator-family MDR pump () gene in , which is widely conserved in species. EbrS represses transcription of as well as its own transcription. Deletion of causes overexpression of , resulting in elevated resistance to many drugs. The and promoters were used in a reporter system to test inducibility by various chemicals. Among the 15 compounds (including five EbrC target drugs) tested, none induced transcription. On the other hand, the promoter was induced by rifampicin and high concentrations of calcium and magnesium. Deletion of did not change rifampicin sensitivity, indicating that the EbrC pump is not involved in rifampicin efflux. Moreover, deletion of caused retardation of colony growth on selected media, and the defect could be suppressed by supplementation with high concentrations of Ca, Mg, Na or K. Based on these results, it is proposed that the primary biological role of most MDR systems in species is not removal of extrinsic drugs, but rather export of specific toxic compounds endogenously synthesized during growth.

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2007-04-01
2019-11-19
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References

  1. August, P. R., Tang, L., Yoon, Y. J., Ning, S., Muller, R., Yu, T. W., Taylor, M., Hoffmann, D., Kim, C. G. & other authors ( 1998; ). Biosynthesis of the ansamycin antibiotic rifamycin: deductions from the molecular analysis of the rif biosynthetic gene cluster of Amycolatopsis mediterranei S699. Chem Biol 5, 69–79.[CrossRef]
    [Google Scholar]
  2. Bentley, S. D., Chater, K. F., Cerdeño-Tárraga, A.-M., Challis, G. L., Thomson, N. R., James, K. D., Harris, D. E., Quail, M. A., Kieser, H. & other authors ( 2002; ). Complete genome sequence of the model actinomycete Streptomyces coelicolor A3(2). Nature 417, 141–147.[CrossRef]
    [Google Scholar]
  3. Cho, Y. H., Kim, E. J., Chung, H. J., Choi, J. H., Chater, K. F., Ahn, B. E., Shin, J. H. & Roe, J. H. ( 2003; ). The pqrAB operon is responsible for paraquat resistance in Streptomyces coelicolor. J Bacteriol 185, 6756–6763.[CrossRef]
    [Google Scholar]
  4. Crameri, R., Davies, J. E. & Hütter, R. ( 1986; ). Plasmid curing and generation of mutations induced with ethidium bromide in streptomycetes. J Gen Microbiol 132, 819–824.
    [Google Scholar]
  5. Dominguez, D. C. ( 2004; ). Calcium signalling in bacteria. Mol Microbiol 54, 291–297.[CrossRef]
    [Google Scholar]
  6. Dyson, P. & Schrempf, H. ( 1987; ). Genetic instability and DNA amplifications in Streptomyces lividans 66. J Bacteriol 169, 4796–4803.
    [Google Scholar]
  7. Eisen, M. B., Spellman, P. T., Brown, P. O. & Botstein, D. ( 1998; ). Cluster analysis and display of genome-wide expression patterns. Proc Natl Acad Sci U S A 95, 14863–14868.[CrossRef]
    [Google Scholar]
  8. Fernandez-Moreno, M. A., Caballero, J. L., Hopwood, D. A. & Malpartida, F. ( 1991; ). The act cluster contains regulatory and antibiotic export genes, direct targets for translational control by the bldA tRNA gene of Streptomyces. Cell 66, 769–780.[CrossRef]
    [Google Scholar]
  9. Gollub, J., Ball, C. A., Binkley, G., Demeter, J., Finkelstein, D. B., Hebert, J. M., Hernandez-Boussard, T., Jin, H., Kaloper, M. & other authors ( 2003; ). The Stanford Microarray Database: data access and quality assessment tools. Nucleic Acids Res 31, 94–96.[CrossRef]
    [Google Scholar]
  10. Grkovic, S., Brown, M. H. & Skurray, R. A. ( 2002; ). Regulation of bacterial drug export systems. Microbiol Mol Biol Rev 66, 671–701.[CrossRef]
    [Google Scholar]
  11. Guilfoile, P. G. & Hutchinson, C. R. ( 1992; ). Sequence and transcriptional analysis of the Streptomyces glaucescens tcmAR tetracenomycin C resistance and repressor gene loci. J Bacteriol 174, 3651–3658.
    [Google Scholar]
  12. Hinrichs, W., Kisker, C., Duvel, M., Muller, A., Tovar, K., Hillen, W. & Saenger, W. ( 1994; ). Structure of the Tet repressor-tetracycline complex and regulation of antibiotic resistance. Science 264, 418–420.[CrossRef]
    [Google Scholar]
  13. Hopwood, D. A., Kieser, T., Wright, H. M. & Bibb, M. J. ( 1983; ). Plasmids, recombination and chromosome mapping in Streptomyces lividans 66. J Gen Microbiol 129, 2257–2269.
    [Google Scholar]
  14. Ikeda, H., Ishikawa, J., Hanamoto, A., Shinose, M., Kikuchi, H., Shiba, T., Sakaki, Y., Hattori, M. & Omura, S. ( 2003; ). Complete genome sequence and comparative analysis of the industrial microorganism Streptomyces avermitilis. Nat Biotechnol 21, 526–531.[CrossRef]
    [Google Scholar]
  15. Jack, D. L., Storms, M. L., Tchieu, J. H., Paulsen, I. T. & Saier, M. H. J. ( 2000; ). A broad-specificity multidrug efflux pump requiring a pair of homologous SMR-type proteins. J Bacteriol 182, 2311–2313.[CrossRef]
    [Google Scholar]
  16. Katz, E., Thompson, C. J. & Hopwood, D. A. ( 1983; ). Cloning and expression of the tyrosinase gene from Streptomyces antibioticus in Streptomyces lividans. J Gen Microbiol 129, 2703–2714.
    [Google Scholar]
  17. Kieser, T., Hopwood, D. A., Wright, H. M. & Thompson, C. J. ( 1982; ). pIJ101, a multi-copy broad host-range Streptomyces plasmid: functional analysis and development of DNA cloning vectors. Mol Gen Genet 185, 223–228.[CrossRef]
    [Google Scholar]
  18. Kieser, T., Bibb, M., Buttner, M. J., Chater, K. F. & Hopwood, D. A. ( 2000; ). Practical Streptomyces Genetics. Norwich: The John Innes Foundation.
  19. Köhler, T., Pechere, J. C. & Plesiat, P. ( 1999; ). Bacterial antibiotic efflux systems of medical importance. Cell Mol Life Sci 56, 771–778.[CrossRef]
    [Google Scholar]
  20. Lee, L.-F., Huang, Y.-J. & Chen, C. W. ( 1996; ). Two classes of ethidium-bromide-resistant mutants of Streptomyces lividans 66. Microbiology 142, 1041–1047.[CrossRef]
    [Google Scholar]
  21. Lee, C. K., Kamitani, Y., Nihira, T. & Yamada, Y. ( 1999; ). Identification and in vivo functional analysis of a virginiamycin S resistance gene (varS) from Streptomyces virginiae. J Bacteriol 181, 3293–3297.
    [Google Scholar]
  22. Lee, L. F., Huang, Y. J. & Chen, C. W. ( 2003; ). Repressed multidrug resistance genes in Streptomyces lividans. Arch Microbiol 180, 176–184.[CrossRef]
    [Google Scholar]
  23. Liu, W. & Shen, B. ( 2000; ). Genes for production of the enediyne antitumor antibiotic C-1027 in Streptomyces globisporus are clustered with the cagA gene that encodes the C-1027 apoprotein. Antimicrob Agents Chemother 44, 382–392.[CrossRef]
    [Google Scholar]
  24. Neyfakh, A. A. ( 1997; ). Natural functions of bacterial multidrug transporters. Trends Microbiol 5, 309–313.[CrossRef]
    [Google Scholar]
  25. Neyfakh, A. A., Bidnenko, V. E. & Chen, L. B. ( 1991; ). Efflux-mediated multidrug resistance in Bacillus subtilis: similarities and dissimilarities with the mammalian system. Proc Natl Acad Sci U S A 88, 4781–4785.[CrossRef]
    [Google Scholar]
  26. Oh, S. H. & Chater, K. F. ( 1997; ). Denaturation of circular or linear DNA facilitates targeted integrative transformation of Streptomyces coelicolor A3(2): possible relevance to other organisms. J Bacteriol 179, 122–127.
    [Google Scholar]
  27. Ohki, R. & Murata, M. ( 1997; ). bmr3, a third multidrug transporter gene of Bacillus subtilis. J Bacteriol 179, 1423–1427.
    [Google Scholar]
  28. Paulsen, I. T., Brown, M. H., Littlejohn, T. G., Mitchell, B. A. & Skurray, R. A. ( 1996; ). Multidrug resistance proteins QacA and QacB from Staphylococcus aureus: membrane topology and identification of residues involved in substrate specificity. Proc Natl Acad Sci U S A 93, 3630–3635.[CrossRef]
    [Google Scholar]
  29. Pospiech, A. & Neumann, B. ( 1995; ). A versatile quick-prep of genomic DNA from gram-positive bacteria. Trends Genet 11, 217–218.[CrossRef]
    [Google Scholar]
  30. Putman, M., van Veen, H. W. & Konings, W. N. ( 2000; ). Molecular properties of bacterial multidrug transporters. Microbiol Mol Biol Rev 64, 672–693.[CrossRef]
    [Google Scholar]
  31. Qin, Z., Peng, K., Zhou, X., Liang, R., Zhou, Q., Chen, H., Hopwood, D. A., Kieser, T. & Deng, Z. ( 1994; ). Development of a gene cloning system for Streptomyces hygroscopicus subsp. yingchengensis, a producer of three useful antifungal compounds, by elimination of three barriers to DNA transfer. J Bacteriol 176, 2090–2095.
    [Google Scholar]
  32. Salah-Bey, K. & Thompson, C. J. ( 1995; ). Unusual regulatory mechanism for a Streptomyces multidrug resistance gene, ptr, involving three homologous protein-binding sites overlapping the promoter region. Mol Microbiol 17, 1109–1119.[CrossRef]
    [Google Scholar]
  33. Salah-Bey, K., Blanc, V. & Thompson, C. J. ( 1995; ). Stress-activated expression of a Streptomyces pristinaespiralis multidrug resistance gene (ptr) in various Streptomyces spp. and Escherichia coli. Mol Microbiol 17, 1001–1012.[CrossRef]
    [Google Scholar]
  34. Takiff, H. E., Cimino, M., Musso, M. C., Weisbrod, T., Martinez, R., Delgado, M. B., Salazar, L., Bloom, B. R. & Jacobs, J. W. R. ( 1996; ). Efflux pump of the proton antiporter family confers low-level fluoroquinolone resistance in Mycobacterium smegmatis. Proc Natl Acad Sci USA 93, 362–366.[CrossRef]
    [Google Scholar]
  35. Thiara, A. S. & Cundliffe, E. ( 1995; ). Analysis of two capreomycin-resistance determinants from Streptomyces capreolus and characterization of the action of their products. Gene 167, 121–126.[CrossRef]
    [Google Scholar]
  36. Ward, J. M., Janssen, G. R., Kieser, T., Bibb, M. J., Buttner, M. J. & Bibb, M. J. ( 1986; ). Construction and characterisation of a series of multi-copy promoter-probe plasmid vectors for Streptomyces using the aminoglycoside phosphotransferase gene from Tn5 as indicator. Mol Gen Genet 203, 468–478.[CrossRef]
    [Google Scholar]
  37. Westrich, L., Domann, S., Faust, B., Bedford, D., Hopwood, D. A. & Bechthold, A. ( 1999; ). Cloning and characterization of a gene cluster from Streptomyces cyanogenus S136 probably involved in landomycin biosynthesis. FEMS Microbiol Lett 170, 381–387.[CrossRef]
    [Google Scholar]
  38. Yonekawa, T., Ohnishi, Y. & Horinouchi, S. ( 2001; ). A calcium-binding protein with four EF-hand motifs in Streptomyces ambofaciens. Biosci Biotechnol Biochem 65, 156–160.[CrossRef]
    [Google Scholar]
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