Functional interaction sites of OprM with MexAB in the Pseudomonas aeruginosa multidrug efflux pump.
Subunit-swapping between Pseudomonas aeruginosa MexAB-OprM and MexEF-OprN efflux pumps has shown that OprM can interact with MexEF to produce a functional efflux pump, but that OprN cannot functionally interact with MexAB. Taking advantage of this subunit selectivity, we carried out experiments using chimeric proteins composed of OprM and OprN to determine which regions of OprM are necessary for functional interaction with MexAB. We constructed two types of chimeric proteins: one with the N-terminal half of OprM and the C-terminal half of OprN (OprMN), and the second with these halves reversed (OprNM). Introduction of either of the chimeric protein genes into a mutant expressing MexEF alone restored the functionality of the efflux pump. However, expression of OprMN or OprNM in the presence of MexAB did not restore the pump functionality, indicating that the both the N- and C-terminal halves of OprM are necessary for a functional interaction with MexAB.
Yoshihara
Eisaku
E
Department of Molecular Life Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa, Japan. eisaku@is.icc.u-tokai.ac.jp
Eda
Shima
S
Kaitou
Sayaka
S
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D054730:Protein Interaction Domains and Motifs; D025941:Protein Interaction Mapping; D011550:Pseudomonas aeruginosa / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
D001425:Bacterial Outer Membrane Proteins; D026901:Membrane Transport Proteins; C118598:MexA protein, Pseudomonas aeruginosa; C118597:MexB protein, Pseudomonas aeruginosa; C402263:OprM protein, Pseudomonas aeruginosa; D011994:Recombinant Proteins