Figure 5. Gradual inhibition. Binding of multiple transcriptional repressors gradually inhibits transcription.

(A) Transcription rate as a function of the number of bound transcriptional repressors. Transcription occurs at the basal rate b in the absence of bound repressors, and decreases linearly to zero for more than k bound repressors. (B) Normalized regulatory function Eq. (11) as a function of repressor concentration x, with N = 12 and k = 0,..., 11 (dark blue to dark red).