Figure 1. Activator synergy.
Several nonexclusive mechanisms can be envisioned by which two transcriptional activators augment each other’s function. (A) Activators A and B cooperatively bind to linked sites. (B) A and B coordinately bind a third protein, X, which stabilizes the binding of A and B. (C) A recruits a histone remodeling protein that facilitates the binding of B. (D) A leads to ‘slippage’ of the nucleosome and thereby uncovers the B binding site. Reproduced with permission from [125].