FIG. 6.

Intrinsic features of the rrnD P1 promoter (−61 to +1) limit its activation by FIS in vivo. rrnB P1 or rrnD P1 promoters were either wild type (containing native FIS sites) or hybrid (containing FIS sites from the other promoter). The fold activation by FIS was determined as the ratio of the β-galactosidase activity of a promoter-lacZ fusion containing the indicated FIS sites to that of the same promoter lacking FIS sites (−61 to +1). Means and standard deviations are derived from at least three independent assays.