Figure 1. Illustration of grammatical rules and their effect on gene expression.
Transcriptional grammar. The rules of transcription regulation are illustrated as “grammar cards”. Each card represents a different rule. For example, the number of binding sites for the same TF, the distance of one TF from the TSS, the orientation of the binding-site relative to the TSS, etc.
Expression function. The function by which each rule affects expression. For example: cooperative binding results in a sigmoidal curve since one binding event increases the probability of another binding to occur, resulting in higher expression. The x-axis changes according to the rule identity. For example, for the rule of binding-site location, the x-axis represents distance from the TSS (in bp).