Regulatory network of a single gene.

<p>Regulatory mechanisms of gene expression include: binding of TF to a promoter site of the DNA; recruitment of RNAP to the promoter region to form the pre-initiation complex; binding of a number of RNAP molecules leading to multiple transcription re-initiations during a time period of gene activation, which is realized by the transcription memory window; gene inactivity period during which RNAP molecule is unable to bind to the promoter region, which is characterized as the second memory window.</p>