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In vitro Investigation of the MexAB Efflux Pump From Pseudomonas aeruginosa
13:40

In vitro Investigation of the MexAB Efflux Pump From Pseudomonas aeruginosa

Published on: February 17, 2014

Functional interaction sites of OprM with MexAB in the Pseudomonas aeruginosa multidrug efflux pump

Eisaku Yoshihara1, Shima Eda, Sayaka Kaitou

  • 1Department of Molecular Life Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan. eisaku@is.icc.u-tokai.ac.jp

FEMS Microbiology Letters
|August 28, 2009
PubMed

Insights

The Pseudomonas aeruginosa MexAB-OprM and MexEF-OprN efflux pumps exhibit subunit selectivity. Both N- and C-terminal halves of OprM are essential for functional interaction with MexAB.

Area of Science:

  • Microbiology
  • Molecular Biology

Background:

  • Pseudomonas aeruginosa possesses multiple multidrug efflux pumps, including MexAB-OprM and MexEF-OprN.
  • These pumps are crucial for bacterial multidrug resistance.
  • Previous studies indicated functional asymmetry in subunit interactions between these pump systems.

Purpose of the Study:

  • To investigate the specific regions of the OprM protein necessary for functional interaction with the MexAB efflux pump.
  • To elucidate the structural determinants of subunit selectivity in Pseudomonas aeruginosa efflux pumps.

Main Methods:

  • Construction and expression of chimeric proteins between OprM and OprN.
  • Functional assessment of chimeric proteins in conjunction with MexAB and MexEF components.
  • Utilizing genetic complementation assays to restore efflux pump activity.

Main Results:

  • Chimeric proteins (OprMN and OprNM) restored functionality when co-expressed with MexEF, indicating OprM regions can interact with MexEF.
  • Neither OprMN nor OprNM restored MexAB efflux pump functionality when co-expressed with MexAB.
  • This suggests that both the N-terminal and C-terminal halves of OprM are indispensable for functional interaction with MexAB.

Conclusions:

  • The functional interaction between OprM and MexAB is critically dependent on the integrity of both the N- and C-terminal halves of OprM.
  • Subunit selectivity exists, with OprM interacting differently with MexAB compared to MexEF.
  • Understanding these interactions is key to developing strategies to inhibit multidrug resistance in Pseudomonas aeruginosa.

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