Cooperative Interactions and DNA-Binding Activity

• There are often multiple copies of the same type of docking site (transcription factor binding site) near one another on a gene.

•  It appears that having several copies of a transcription factor binding to adjacent sites leads to an amplified or superadditive effect of the transcription factors on activating transcription.

• It is now thought that this works by the multiple bound sites acting to catalyze the formation of an enhanceosome, a large protein complex that mediates the interactions between distant enhancers and basal transcriptional machinery.