J Bacteriol, June 1998, p. 2995-2998, Vol. 180, No. 11
0021-9193/98/$04.00+0
Copyright © 1998, American Society for Microbiology. All rights reserved.


Center for Adaptation Genetics and Drug Resistance and Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111
Received 9 September 1997/Accepted 1 April 1998
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.
Present address: Department of Veterinary and Microbiological
Sciences, North Dakota State University, Fargo, ND 58105.
Present address: Laboratoire de Recherche Moléculaire sur
les Antibiotiques, Université Paris VI, 75270 Paris Cedex 06, France.
This article has been cited by other articles:
| Appl. Environ. Microbiol. | Infect. Immun. | Eukaryot. Cell |
|---|---|---|
| Mol. Cell. Biol. | J. Virol. | Microbiol. Mol. Biol. Rev. |
| ALL ASM JOURNALS |