FIGURE 2 

Activation functions at distal and is attenuated by intrinsic promoter strength. (A) Measurements of promoters activated at distal operators. These promoters respond only to LuxR (solid triangles) or AraC (open triangles) induction. Some promoters fail to respond even though they contain a functional operator (points on the solid line). The activation ceiling (red dashed line) represents the maximal observed activation and does not depend on the unregulated expression level. (B) Promoters containing operators at core (squares) or proximal (circles) do not respond to induction.