The gene specifying the ethidium efflux system of Escherichia coli has been cloned on a 3.2 kbp HindIII fragment and located on a 1.2 kbp fragment within this. Cross-resistance studies indicate that the system has a broad specificity for monovalent cations and the gene shows no hybridisation with similar genes found in Staphylococci. © 1990.
Purewal, A. S., Jones, I. G., & Midgley, M. (1990). Cloning of the ethidium efflux gene from Escherichia coli. FEMS Microbiology Letters, 68(1–2), 73–76. https://doi.org/10.1016/0378-1097(90)90127-C