This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Nehme, D.
Right arrow Articles by Poole, K.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Nehme, D.
Right arrow Articles by Poole, K.

 Previous Article  |  Next Article 

Journal of Bacteriology, May 2004, p. 2973-2983, Vol. 186, No. 10
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.10.2973-2983.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Assembly of the MexAB-OprM Multidrug Efflux System of Pseudomonas aeruginosa: Identification and Characterization of Mutations in mexA Compromising MexA Multimerization and Interaction with MexB

Dominic Nehme, Xian-Zhi Li, Rachel Elliot, and Keith Poole*

Department of Microbiology and Immunology, Queen's University, Kingston, Ontario K7L 3N6, Canada

Received 13 January 2004/ Accepted 4 February 2004

The membrane fusion protein (MFP) component, MexA, of the MexAB-OprM multidrug efflux system of P. aeruginosa is proposed to link the inner (MexB) and outer (OprM) membrane components of this pump as a probable oligomer. A cross-linking approach confirmed the in vivo interaction of MexA and MexB, while a LexA-based assay for assessing protein-protein interaction similarly confirmed MexA multimerization. Mutations compromising the MexA contribution to antibiotic resistance but yielding wild-type levels of MexA were recovered and shown to map to two distinct regions within the N- and C-terminal halves of the protein. Most of the N-terminal mutations occurred at residues that are highly conserved in the MFP family (P68, G72, L91, A108, L110, and V129), consistent with these playing roles in a common feature of these proteins (e.g., oligomerization). In contrast, the majority of the C-terminal mutations occurred at residues poorly conserved in the MFP family (V264, N270, H279, V286, and G297), with many mapping to a region of MexA that corresponds to a region in the related MFP of Escherichia coli, AcrA, that is implicated in binding to its RND component, AcrB (C. A. Elkins and H. Nikaido, J. Bacteriol. 185:5349-5356, 2003). Given the noted specificity of MFP-RND interaction in this family of pumps, residues unique to MexA may well be important for and define the MexA interaction with its RND component, MexB. Still, all but one of the MexA mutations studied compromised MexA-MexB association, suggesting that native structure and/or proper assembly of the protein may be necessary for this.

* Corresponding author. Mailing address: Department of Microbiology and Immunology, Queen's University, Kingston, Ontario K7L 3N6, Canada. Phone: (613) 533-6677. Fax: (613) 533-6796. E-mail: poolek{at}post.queensu.ca.

Journal of Bacteriology, May 2004, p. 2973-2983, Vol. 186, No. 10
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.10.2973-2983.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:

  • Ge, Q., Yamada, Y., Zgurskaya, H. (2009). The C-Terminal Domain of AcrA Is Essential for the Assembly and Function of the Multidrug Efflux Pump AcrAB-TolC. J. Bacteriol. 191: 4365-4371 [Abstract] [Full Text]  
  • Vettoretti, L., Plesiat, P., Muller, C., El Garch, F., Phan, G., Attree, I., Ducruix, A., Llanes, C. (2009). Efflux Unbalance in Pseudomonas aeruginosa Isolates from Cystic Fibrosis Patients. Antimicrob. Agents Chemother. 53: 1987-1997 [Abstract] [Full Text]  
  • Marshall, B., Stintzi, A., Gilmour, C., Meyer, J.-M., Poole, K. (2009). Citrate-mediated iron uptake in Pseudomonas aeruginosa: involvement of the citrate-inducible FecA receptor and the FeoB ferrous iron transporter. Microbiology 155: 305-315 [Abstract] [Full Text]  
  • Fraud, S., Campigotto, A. J., Chen, Z., Poole, K. (2008). MexCD-OprJ Multidrug Efflux System of Pseudomonas aeruginosa: Involvement in Chlorhexidine Resistance and Induction by Membrane-Damaging Agents Dependent upon the AlgU Stress Response Sigma Factor. Antimicrob. Agents Chemother. 52: 4478-4482 [Abstract] [Full Text]  
  • Davidson, A. L., Dassa, E., Orelle, C., Chen, J. (2008). Structure, Function, and Evolution of Bacterial ATP-Binding Cassette Systems. Microbiol. Mol. Biol. Rev. 72: 317-364 [Abstract] [Full Text]  
  • Oglesby, L. L., Jain, S., Ohman, D. E. (2008). Membrane topology and roles of Pseudomonas aeruginosa Alg8 and Alg44 in alginate polymerization. Microbiology 154: 1605-1615 [Abstract] [Full Text]  
  • Patriquin, G. M., Banin, E., Gilmour, C., Tuchman, R., Greenberg, E. P., Poole, K. (2008). Influence of Quorum Sensing and Iron on Twitching Motility and Biofilm Formation in Pseudomonas aeruginosa. J. Bacteriol. 190: 662-671 [Abstract] [Full Text]  
  • Krishnamoorthy, G., Tikhonova, E. B., Zgurskaya, H. I. (2008). Fitting Periplasmic Membrane Fusion Proteins to Inner Membrane Transporters: Mutations That Enable Escherichia coli AcrA To Function with Pseudomonas aeruginosa MexB. J. Bacteriol. 190: 691-698 [Abstract] [Full Text]  
  • Nehme, D., Poole, K. (2007). Assembly of the MexAB-OprM Multidrug Pump of Pseudomonas aeruginosa: Component Interactions Defined by the Study of Pump Mutant Suppressors. J. Bacteriol. 189: 6118-6127 [Abstract] [Full Text]  
  • Nehme, D., Poole, K. (2005). Interaction of the MexA and MexB Components of the MexAB-OprM Multidrug Efflux System of Pseudomonas aeruginosa: Identification of MexA Extragenic Suppressors of a T578I Mutation in MexB. Antimicrob. Agents Chemother. 49: 4375-4378 [Abstract] [Full Text]  
  • Poole, K. (2005). Efflux-mediated antimicrobial resistance. J Antimicrob Chemother 56: 20-51 [Abstract] [Full Text]  
  • Akama, H., Kanemaki, M., Yoshimura, M., Tsukihara, T., Kashiwagi, T., Yoneyama, H., Narita, S.-i., Nakagawa, A., Nakae, T. (2004). Crystal Structure of the Drug Discharge Outer Membrane Protein, OprM, of Pseudomonas aeruginosa: DUAL MODES OF MEMBRANE ANCHORING AND OCCLUDED CAVITY END. J. Biol. Chem. 279: 52816-52819 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»