title: BC4707 is a major facilitator superfamily multidrug resistance transport protein from Bacillus cereus implicated in fluoroquinolone tolerance.
abstract: Transcriptional profiling highlighted a subset of genes encoding putative multidrug transporters in the pathogen Bacillus cereus that were up-regulated during stress produced by bile salts. One of these multidrug transporters (BC4707) was selected for investigation. Functional characterization of the BC4707 protein in Escherichia coli revealed a role in the energized efflux of xenobiotics. Phenotypic analyses after inactivation of the gene bc4707 in Bacillus cereus ATCC14579 suggested a more specific, but modest role in the efflux of norfloxacin. In addition to this, transcriptional analyses showed that BC4707 is also expressed during growth of B. cereus under non-stressful conditions where it may have a role in the normal physiology of the bacteria. Altogether, the results indicate that bc4707, which is part of the core genome of the B. cereus group of bacteria, encodes a multidrug resistance efflux protein that is likely involved in maintaining intracellular homeostasis during growth of the bacteria.
authors.affiliation: Laboratory for Microbial Dynamics, Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway.
authors.forename: Roger
authors.initials: R
authors.lastname: Simm
authors.forename: Aniko
authors.initials: A
authors.lastname: Vörös
authors.forename: Jaakko V
authors.initials: JV
authors.lastname: Ekman
authors.forename: Marianne
authors.initials: M
authors.lastname: Sødring
authors.forename: Ingerid
authors.initials: I
authors.lastname: Nes
authors.forename: Jasmin K
authors.initials: JK
authors.lastname: Kroeger
authors.forename: Massoud
authors.initials: M
authors.lastname: Saidijam
authors.forename: Kim E
authors.initials: KE
authors.lastname: Bettaney
authors.forename: Peter J F
authors.initials: PJ
authors.lastname: Henderson
authors.forename: Mirja
authors.initials: M
authors.lastname: Salkinoja-Salonen
authors.forename: Anne-Brit
authors.initials: AB
authors.lastname: Kolstø
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001409:Bacillus cereus / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000502:physiology*; D001647:Bile Acids and Salts / Q000378:metabolism; D018432:Drug Resistance, Multiple; D024841:Fluoroquinolones / Q000494:pharmacology*; D020868:Gene Silencing; D020411:Oligonucleotide Array Sequence Analysis; D021381:Protein Transport; D013312:Stress, Physiological; D014158:Transcription, Genetic
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001647:Bile Acids and Salts; D024841:Fluoroquinolones