@article{mbs:/content/journal/micro/10.1099/mic.0.031260-0, author = "Mima, Takehiko and Kohira, Naoki and Li, Yang and Sekiya, Hiroshi and Ogawa, Wakano and Kuroda, Teruo and Tsuchiya, Tomofusa", title = "Gene cloning and characteristics of the RND-type multidrug efflux pump MuxABC-OpmB possessing two RND components in Pseudomonas aeruginosa", journal= "Microbiology", year = "2009", volume = "155", number = "11", pages = "3509-3517", doi = "https://doi.org/10.1099/mic.0.031260-0", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/mic.0.031260-0", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", keywords = "RND, resistance nodulation cell division", abstract = " muxA-muxB-muxC-opmB (formerly PA2528-PA2527-PA2526-opmB), encoding a putative resistance nodulation cell division (RND)-type multidrug efflux pump system, was cloned from Pseudomonas aeruginosa PAO1. Introduction of muxABC-opmB into P. aeruginosa YM64, a drug-hypersusceptible strain, led to elevated MICs of aztreonam, macrolides, novobiocin and tetracycline. Since muxB and muxC, both of which encode RND components, were essential for function, MuxABC-OpmB is thought to be a drug efflux pump with four components. One novobiocin-resistant mutant, PMX725, isolated from P. aeruginosa PMX7 showed elevated resistance not only to novobiocin but also to aztreonam, macrolides and tetracycline. Increased mRNA expression of muxABC-opmB was observed in the mutant PMX725 compared with the parental strain. Sequencing analysis revealed that a single-nucleotide insertion had occurred in the deduced promoter region for muxABC-opmB in PMX725. In this study, we have characterized the last RND-type multidrug efflux pump predicted from the genome sequence in P. aeruginosa.", }