title: Multidrug resistance following expression of the Escherichia coli marA gene in Mycobacterium smegmatis.
abstract: Expression of the Escherichia coli multiple antibiotic resistance marA gene cloned in Mycobacterium smegmatis produced increased resistance to multiple antimicrobial agents, including rifampin, isoniazid, ethambutol, tetracycline, and chloramphenicol. Cloned marR or marA cloned in the antisense direction had no effect. Resistance changes were lost with spontaneous loss of the plasmid bearing marA. A MarA mutant protein, having an insertional mutation within either of its two alpha-helices of the first putative helix-turn-helix domain, failed to produce the multiresistance phenotype in E. coli and M. smegmatis, indicating that this region is critical for MarA function. These results strongly suggest that E. coli marA functions in M. smegmatis and that a mar-like regulatory system exists in this organism.
authors.affiliation: Center for Adaptation Genetics and Drug Resistance and Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
authors.forename: P F
authors.initials: PF
authors.lastname: McDermott
authors.forename: D G
authors.initials: DG
authors.lastname: White
authors.forename: I
authors.initials: I
authors.lastname: Podglajen
authors.forename: M N
authors.initials: MN
authors.lastname: Alekshun
authors.forename: S B
authors.initials: SB
authors.lastname: Levy
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D018834:Chaperonin 60 / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D029968:Escherichia coli Proteins; D015870:Gene Expression; D019077:Helix-Turn-Helix Motifs; D009161:Mycobacterium / Q000187:drug effects* / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011993:Recombinant Fusion Proteins
chemical_list: D001426:Bacterial Proteins; D018834:Chaperonin 60; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C080002:MarA protein, E coli; D011993:Recombinant Fusion Proteins