Skip to main content
PMC home page
Journal of Bacteriology logoLink to Journal of Bacteriology
. 1997 Jul;179(13):4123–4128. doi: 10.1128/jb.179.13.4123-4128.1997

The MtrR repressor binds the DNA sequence between the mtrR and mtrC genes of Neisseria gonorrhoeae.

C E Lucas 1, J T Balthazar 1, K E Hagman 1, W M Shafer 1
PMCID: PMC179230  PMID: 9209024

Abstract

Gonococcal resistance to antimicrobial hydrophobic agents (HAs) is due to energy-dependent removal of HAs from the bacterial cell by the MtrCDE membrane-associated efflux pump. The mtrR (multiple transferrable resistance Regulator) gene encodes a putative transcriptional repressor protein (MtrR) believed to be responsible for regulation of mtrCDE gene expression. Gel mobility shift and DNase I footprint assays that used a maltose-binding protein (MBP)-MtrR fusion protein demonstrated that the MtrR repressor is capable of specifically binding the DNA sequence between the mtrR and mtrC genes. This binding site was localized to a 26-nucleotide stretch that includes the promoter utilized for mtrCDE transcription and, on the complementary strand, a 22-nucleotide stretch that contains the -35 region of the mtrR promoter. A single transition mutation (A-->G) within the MtrR-binding site decreased the affinity of the target DNA for MtrR and enhanced gonococcal resistance to HAs when introduced into HA-susceptible strain FA19 by transformation. Since this mutation enhanced expression of the mtrCDE gene complex but decreased expression of the mtrR gene, the data are consistent with the notion that MtrR acts as a transcriptional repressor of the mtrCDE efflux pump protein genes.

Full Text

The Full Text of this article is available as a PDF (986.5 KB).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bertrand K. P., Postle K., Wray L. V., Jr, Reznikoff W. S. Overlapping divergent promoters control expression of Tn10 tetracycline resistance. Gene. 1983 Aug;23(2):149–156. doi: 10.1016/0378-1119(83)90046-x. [DOI] [PubMed] [Google Scholar]
  2. Brennan R. G., Matthews B. W. Structural basis of DNA-protein recognition. Trends Biochem Sci. 1989 Jul;14(7):286–290. doi: 10.1016/0968-0004(89)90066-2. [DOI] [PubMed] [Google Scholar]
  3. Guymon L. F., Sparling P. F. Altered crystal violet permeability and lytic behavior in antibiotic-resistant and -sensitive mutants of Neisseria gonorrhoeae. J Bacteriol. 1975 Nov;124(2):757–763. doi: 10.1128/jb.124.2.757-763.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Guymon L. F., Walstad D. L., Sparling P. F. Cell envelope alterations in antibiotic-sensitive and-resistant strains of Neisseria gonorrhoeae. J Bacteriol. 1978 Oct;136(1):391–401. doi: 10.1128/jb.136.1.391-401.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Hagman K. E., Pan W., Spratt B. G., Balthazar J. T., Judd R. C., Shafer W. M. Resistance of Neisseria gonorrhoeae to antimicrobial hydrophobic agents is modulated by the mtrRCDE efflux system. Microbiology. 1995 Mar;141(Pt 3):611–622. doi: 10.1099/13500872-141-3-611. [DOI] [PubMed] [Google Scholar]
  6. Hagman K. E., Shafer W. M. Transcriptional control of the mtr efflux system of Neisseria gonorrhoeae. J Bacteriol. 1995 Jul;177(14):4162–4165. doi: 10.1128/jb.177.14.4162-4165.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Hillen W., Berens C. Mechanisms underlying expression of Tn10 encoded tetracycline resistance. Annu Rev Microbiol. 1994;48:345–369. doi: 10.1146/annurev.mi.48.100194.002021. [DOI] [PubMed] [Google Scholar]
  8. Levy S. B. Active efflux mechanisms for antimicrobial resistance. Antimicrob Agents Chemother. 1992 Apr;36(4):695–703. doi: 10.1128/aac.36.4.695. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Lu F., Churchward G. Conjugative transposition: Tn916 integrase contains two independent DNA binding domains that recognize different DNA sequences. EMBO J. 1994 Apr 1;13(7):1541–1548. doi: 10.1002/j.1460-2075.1994.tb06416.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Lucas C. E., Hagman K. E., Levin J. C., Stein D. C., Shafer W. M. Importance of lipooligosaccharide structure in determining gonococcal resistance to hydrophobic antimicrobial agents resulting from the mtr efflux system. Mol Microbiol. 1995 Jun;16(5):1001–1009. doi: 10.1111/j.1365-2958.1995.tb02325.x. [DOI] [PubMed] [Google Scholar]
  11. Ma D., Alberti M., Lynch C., Nikaido H., Hearst J. E. The local repressor AcrR plays a modulating role in the regulation of acrAB genes of Escherichia coli by global stress signals. Mol Microbiol. 1996 Jan;19(1):101–112. doi: 10.1046/j.1365-2958.1996.357881.x. [DOI] [PubMed] [Google Scholar]
  12. Ma D., Cook D. N., Alberti M., Pon N. G., Nikaido H., Hearst J. E. Genes acrA and acrB encode a stress-induced efflux system of Escherichia coli. Mol Microbiol. 1995 Apr;16(1):45–55. doi: 10.1111/j.1365-2958.1995.tb02390.x. [DOI] [PubMed] [Google Scholar]
  13. Maness M. J., Sparling P. F. Multiple antibiotic resistance due to a single mutation in Neisseria gonorrhoeae. J Infect Dis. 1973 Sep;128(3):321–330. doi: 10.1093/infdis/128.3.321. [DOI] [PubMed] [Google Scholar]
  14. McAllister C. F., Stephens D. S. Analysis in Neisseria meningitidis and other Neisseria species of genes homologous to the FKBP immunophilin family. Mol Microbiol. 1993 Oct;10(1):13–23. doi: 10.1111/j.1365-2958.1993.tb00899.x. [DOI] [PubMed] [Google Scholar]
  15. McIver K. S., Heath A. S., Green B. D., Scott J. R. Specific binding of the activator Mga to promoter sequences of the emm and scpA genes in the group A streptococcus. J Bacteriol. 1995 Nov;177(22):6619–6624. doi: 10.1128/jb.177.22.6619-6624.1995. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Morse S. A., Lysko P. G., McFarland L., Knapp J. S., Sandstrom E., Critchlow C., Holmes K. K. Gonococcal strains from homosexual men have outer membranes with reduced permeability to hydrophobic molecules. Infect Immun. 1982 Aug;37(2):432–438. doi: 10.1128/iai.37.2.432-438.1982. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Nikaido H. Prevention of drug access to bacterial targets: permeability barriers and active efflux. Science. 1994 Apr 15;264(5157):382–388. doi: 10.1126/science.8153625. [DOI] [PubMed] [Google Scholar]
  18. Okusu H., Ma D., Nikaido H. AcrAB efflux pump plays a major role in the antibiotic resistance phenotype of Escherichia coli multiple-antibiotic-resistance (Mar) mutants. J Bacteriol. 1996 Jan;178(1):306–308. doi: 10.1128/jb.178.1.306-308.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Orchard K., May G. E. An EMSA-based method for determining the molecular weight of a protein--DNA complex. Nucleic Acids Res. 1993 Jul 11;21(14):3335–3336. doi: 10.1093/nar/21.14.3335. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Pan W., Spratt B. G. Regulation of the permeability of the gonococcal cell envelope by the mtr system. Mol Microbiol. 1994 Feb;11(4):769–775. doi: 10.1111/j.1365-2958.1994.tb00354.x. [DOI] [PubMed] [Google Scholar]
  21. Poole K., Heinrichs D. E., Neshat S. Cloning and sequence analysis of an EnvCD homologue in Pseudomonas aeruginosa: regulation by iron and possible involvement in the secretion of the siderophore pyoverdine. Mol Microbiol. 1993 Nov;10(3):529–544. doi: 10.1111/j.1365-2958.1993.tb00925.x. [DOI] [PubMed] [Google Scholar]
  22. Scudamore R. A., Beveridge T. J., Goldner M. Penetrability of the outer membrane of Neisseria gonorrhoeae in relation to acquired resistance to penicillin and other antibiotics. Antimicrob Agents Chemother. 1979 Jun;15(6):820–827. doi: 10.1128/aac.15.6.820. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Shafer W. M., Balthazar J. T., Hagman K. E., Morse S. A. Missense mutations that alter the DNA-binding domain of the MtrR protein occur frequently in rectal isolates of Neisseria gonorrhoeae that are resistant to faecal lipids. Microbiology. 1995 Apr;141(Pt 4):907–911. doi: 10.1099/13500872-141-4-907. [DOI] [PubMed] [Google Scholar]
  24. Sparling P. F., Sarubbi F. A., Jr, Blackman E. Inheritance of low-level resistance to penicillin, tetracycline, and chloramphenicol in Neisseria gonorrhoeae. J Bacteriol. 1975 Nov;124(2):740–749. doi: 10.1128/jb.124.2.740-749.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Suzuki M., Yagi N., Gerstein M. DNA recognition and superstructure formation by helix-turn-helix proteins. Protein Eng. 1995 Apr;8(4):329–338. doi: 10.1093/protein/8.4.329. [DOI] [PubMed] [Google Scholar]

Articles from Journal of Bacteriology are provided here courtesy of American Society for Microbiology (ASM)

RESOURCES