Other Transcription Activators

Transcription activators are dimeric proteins
with distinct functional domains: a DNA-binding
domain and an activation domain. The DNAbinding
domain interacts with specific regulatory
DNA sequences. The activation domain interacts
with other proteins that stimulate transcription.
Transcription activators participate in
the assembly of the initiation complex, for example,
by stimulating the binding of transcription
factor IID (TFIID, see p. 212) to the promoter.
Other activators may interact with
general transcription factors. They provide a
second level of transcriptional control.