title: Assignment of the outer-membrane-subunit-selective domain of the membrane fusion protein in the tripartite xenobiotic efflux pump of Pseudomonas aeruginosa.
abstract: Early in vivo experiments revealed that the MexA-MexB dipartite pump unit of Pseudomonas aeruginosa conferred drug resistance to the cells, which expressed OprM, but not to the OprN-bearing cells. While the MexE-MexF unit interplayed with either the outer membrane subunits. Taking advantage of this subunit selectivity, we selected the MexA mutant that gained the ability to interplay with OprN. Four mutants have been isolated and all showed an amino acid substitution (Q116R) in the coiled-coil domain of MexA. The hybrid protein bearing the coiled-coil domain of MexA and the remainder domains from MexE retained the ability to interplay with OprM, but lost the functional interplay with OprN. These results established that the coiled-coil domain of the membrane fusion protein is responsible for selecting the compatible outer membrane subunit.
authors.affiliation: Department of Molecular Life Science, Tokai University School of Medicine, Isehara, Japan.
authors.forename: Shima
authors.initials: S
authors.lastname: Eda
authors.forename: Hideaki
authors.initials: H
authors.lastname: Maseda
authors.forename: Eisaku
authors.initials: E
authors.lastname: Yoshihara
authors.forename: Taiji
authors.initials: T
authors.lastname: Nakae
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D024901:Drug Resistance, Multiple, Bacterial; D015964:Gene Expression Regulation, Bacterial; D026901:Membrane Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D016296:Mutagenesis; D025941:Protein Interaction Mapping; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D015262:Xenobiotics / Q000378:metabolism / Q000494:pharmacology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D026901:Membrane Transport Proteins; C118598:MexA protein, Pseudomonas aeruginosa; C402263:OprM protein, Pseudomonas aeruginosa; C105708:OprN protein, Pseudomonas aeruginosa; D015262:Xenobiotics