[Subcloning of copper resistance promoters from Escherichia coli]

There were two promoters, PpcoA and PpcoE, in the copper resistant determinant from Escherichia coli. Either of them contains the copper box. In order to confirm the importance of copper box in the copper resistance promoters and to study their characteristics, several fragments of both promoters were subcloned using pUCD615 as reporter vector into its SmaI site. The results of restriction endonuclease digestion and the results of reporter gene lux-luciferase activities indicated that both of the Ppco short-lux fusions didn't show any luciferase activities, which indicated that these two fragments (Ppco short) couldn't act as promoters, and thus confirming the copper box was essential to copper resistance. If there were no copper box in the Ppco promoters, there would be no copper resistance in the E. coli.