Geis depicts Transcription Factor II D (TFIID) in orange like TBP, but shaded darker to express the importance of TBP within TFIID.

Used with permission from the Howard Hughes Medical Institute (www.hhmi.org). All rights reserved.


TBP is only one component of a larger initiation factor (Transcription Factor II D, or TFIID). Aside from TBP, TFIID is also composed of several TBP associated factors (TAFs) which facilitate transcription initiation. TFIID is the first of several transcription factors involved in transcription initiation. Currently, the crystal structure of TFIID with DNA has not determined.