Involvement of the gonococcal MtrE protein in the resistance of Neisseria gonorrhoeae to toxic hydrophobic agents
R. M. Delahay1, B. D. Robertson1, J. T. Balthazar2, W. M. Shafer1,2,3, C. A. Ison1
Affiliations: 1 Department of Medical Microbiology, Imperial College School of Medicine at St Mary's, Norfolk Place, London W2 1PG, UK 2 Laboratories of Microbial Pathogenesis, Medical Research Service, VA Medical Center (Atlanta), Decatur, GA 30033, USA 3 Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, GA 30322, USA
*Author for correspondence: C. A. Ison. Tel: + 44 171 594 3965. Fax: +44 171 262 6299. e-mail: [email protected]
Published: 01 July 1997 https://doi.org/10.1099/00221287-143-7-2127
Summary: Low-level resistance of Neisseria gonorrhoeae to toxic hydrophobic agents (HAs), including some antibiotics, is chromosomally mediated via the multiple transferable resistance (mtr) efflux system. The gene encoding the 48.3 kDa outer-membrane protein MtrE, which is associated with the mtr phenotype, was identified and is homologous to export-associated outer-membrane proteins, including the OprM (formerly OprK) lipoprotein of Pseudomonas aeruginosa. Insertional inactivation of the mtrE gene in N. gonorrhoeae strain FA19 resulted in the loss of the outer-membrane protein, with concomitant hypersusceptibility of the mutant strain to a range of HAs. The properties of this mutant confirmed the role of MtrE in multidrug resistance mediated by an active efflux mechanism. Secondary structure predictions for MtrE indicated a largely hydrophilic protein with a single α-helical transmembrane region. A transposon-like element, similar to that found downstream of the region containing the promoters for mtrR and mtrC in Neisseria meningitidis, was identified 63 bp downstream of the mtrE gene.
Keyword(s): antimicrobial resistance , efflux , hydrophobic agents , MtrE and Neisseria gonorrhoeae
This study was supported by the:
Joint Standing Research Committee, St Mary's Hospital (C.A.I.) and NIH (Award AI-21150)
© Society for General Microbiology 1997
/content/journal/micro/10.1099/00221287-143-7-2127
/deliver/fulltext/micro/143/7/mic-143-7-2127.html?itemId=/content/journal/micro/10.1099/00221287-143-7-2127&mimeType=html&fmt=ahah
Abadi F. J. R., Carter P. E., Cash P., Pennington T. H. 1996; Rifampin resistance in Neisseria meningitidis due to alterations in membrane permeability. Antimicrob Agents Chemother 40:646–651
Brendel V., Bucher P., Nourbakhsh I. R., Blaisdell E., Karlin S. 1992; Methods and algorithms for statistical analysis of protein sequences. Proc Natl Acad Sci USA 89:2002–2006
Burns J. L., Wadsworth C. D., Barry J. J., Goodall C. P. 1996; Nucleotide sequence analysis of a gene from Burkholderia (Pseudomonas) cepacia encoding an outer membrane lipoprotein involved in multiple antibiotic resistance. Antimicrob Agents Chemother 40:307–313
Chou P. Y., Fasman G. D. 1978; Empirical prediction of protein conformation. Annu Rev Biochem 47:251–276
Correia F. F., Inouye S., Inouye M. 1988; A family of small repeated elements with some transposon-like properties in the genome of Neisseria gonorrhoeae . J Biol Chem 263:12194–12198
Devereux J., Haeberli P., Smithies O. 1984; A comprehensive set of sequence analysis programs for the VAX. Nucleic Acids Res 12:387–395
Economou A., Hamilton W. D. O., Johnston A. W. B., Downie J. A. 1990; The Rhizobium nodulation gene nodO encodes a Ca2+-binding protein that is exported without N-terminal cleavage and is homologous to haemolysin and related proteins. EMBO J 9:349–354
Fath M. J., Kolter R. 1993; ABC transporters: bacterial exporters. Microbiol Rev 57:995–1017
Fralick J. A., Burns-Keliher L. L. 1994; Additive effect of tolC and rfa mutations on the hydrophobic barrier of the outer membrane of Escherichia coli K-12. J Bacterial 176:6404–6406
Garnier J., Osguthorpe D. J., Robson B. 1978; Analysis of the accuracy and implications of simple methods for predicting the secondary structure of globular proteins. J Mol Biol 120:97–120
Goodman S. D., Scocca J. J. 1988; Identification and arrangement of the DNA sequence recognised in specific transformation of Neisseria gonorrhoeae . Proc Natl Acad Sci USA 85:6982–6986
Guymon L. F., Walstad D. L., Sparling P. F. 1978; Cell envelope alterations in antibiotic-sensitive and -resistant strains of Neisseria gonorrhoeae . J Bacteriol 136:391–401
Hagman K. E., Shafer W. M. 1995; Transcriptional control of the mtr efflux system of Neisseria gonorrhoeae . J Bacteriol 177:4162–4165
Hagman K. E., Pan W., Spratt B. G., Balthazar J. T., Judd R. C., Shafer W. S. 1995; Resistance of Neisseria gonorrhoeae to antimicrobial hydrophobic agents is modulated by the mtrRCDE efflux system. Microbiology 141:611–622
Hayashi S., Wu H. C. 1990; Lipoproteins in bacteria. J Bioenerg Biomembr 22:451–471
Kyte J., Doolittle R. F. 1982; A simple method for displaying the hydropathic character of a protein. J Mol Biol 157:105–132
Lucas C. E., Hagman K. E., Levin J. G,, Stein D. C., Shafer W. M. 1995; Importance of lipooligosaccharide structure in determining gonococcal resistance to hydrophobic antimicrobial agents resulting from the mtr efflux system. Mol Microbiol 16:1001–1009
Ma D., Cook D. N., Alberti M., Pon N. G., Nikaido H., Hearst J. E. 1993; Molecular cloning and characterisation of acrA and acrE genes of Escherichia coli . J Bacteriol 175:6299–6313
Ménard R., Sansonetti P. J., Parsot C. 1993; Nonpolar mutagenesis of the ipa genes defines IpaB, IpaC, and IpaD as effectors of Shigella flexneri entry into epithelial cells. J Bacteriol 175:5899–5906
Morona R., Manning P. A., Reeves P. 1983; Identification and characterization of the TolC protein, an outer membrane protein from Escherichia coli . J Bacteriol 153:693–699
Morse S. A., Lysko P. G., McFarland L., Knapp J. S., Sandstrom E., Critchlow C., Holmes K. K. 1982; Gonococcal strains from homosexual men have outer membranes with reduced permeability to hydrophobic molecules. Infect Immun 37:432–438
Nikaido H. 1994; Prevention of drug access to bacterial targets: permeability barriers and active efflux. Science 264:382–387
Nikaido H., Saier M. H. , Jr 1992; Transport proteins in bacteria: common themes in their design. Science 258:936–942
Pan W., Spratt B. G. 1994; Regulation of the permeability of the gonococcal cell envelope by the mtr system. Mol Microbiol 11:769–775
Poole K., Krebes K., McNally C., Neshat S. 1993; Multiple antibiotic resistance in Pseudomonas aeruginosa: evidence for involvement of an efflux operon. J Bacteriol 175:7363–7372
Rost B., Sander C. 1993; Prediction of protein secondary structure at better than 70% accuracy. J Mol Biol 232:584–599
Saier M. H., Tam R., Reizer A., Reizer J. 1994; Two novel families of bacterial membrane proteins concerned with nodu-lation, cell division and transport. Mol Microbiol 11:841–847
Shafer W. M., Guymon L. F., Lind I., Sparling P. F. 1984; Identification of an envelope mutation (env-10) resulting in increased antibiotic susceptibility and pyocin resistance in a clinical isolate of Neisseria gonorrhoeae . Antimicrob Agents Chemother 25:767–769
Shafer W. M., Balthazar J. T., Hagman K. E., Morse S. A. 1995; 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 141:907–911
Sparling P. F., Sarubbi F. A., Jr 8t Blackman E. 1975; Inheritance of low-level resistance to penicillin, tetracycline, and chloramphenicol in Neisseria gonorrhoeae . J Bacteriol 124:740–749
Stern A., Nickel P., Meyer T. F., So M. 1984; Opacity determinants of Neisseria gonorrhoeae: gene expression and chromosomal linkage to the gonococcal pilus gene. Cell 37:447–456
Surin B. P., Watson J. M., Hamilton W. D., Economou A., Downie J. A. 1990; Molecular characterisation of the nodu-lation gene, nodT, from two biovars of Rhizobium leguminosarum . Mol Microbiol 4:245–252
Wang R. C., Seror S. J., Blight M., Pratt J. M., Broome-Smith J. K., Holland I. B. 1991; Analysis of the membrane organization of an Escherichia coli protein translocator, HlyB, a member of a large family of prokaryote and eukaryote surface transport proteins. J Mol Biol 217:441–454
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-143-7-2127
Microbiology 143, 2127 (1997); https://doi.org/10.1099/00221287-143-7-2127
10.1099/00221287-143-7-2127