1.
They act as activators of transcription. This is
through increasing the affinity of the RNA polymerase on the promoter
2.
They could act as repressors. This way, when
they bind to their active sites, they
repress the binding of the RNA polymerase on the promoter
3.
Transcription factors at one site could affect transcription of genes on another site on the
DNA. The flexibility of the DNA (by forming loops) allows for this phenomenon.
