Correct option is B
TFIIH is a transcription factor that plays a critical role in promoter opening and clearance during transcription initiation. It has ATPase and helicase activities, which are essential for unwinding the DNA at the promoter region, allowing the transcription machinery to access the DNA template. The helicase activity of TFIIH helps to unwind the DNA and the ATPase activity provides the energy required for this process. Additionally, TFIIH is involved in the phosphorylation of RNA polymerase II, which is necessary for transcription initiation and the transition into the elongation phase.
Information Booster:
TFIIH is composed of multiple subunits, including the helicase activity, which is essential for unwinding the DNA at the promoter to allow RNA polymerase II to bind and initiate transcription.
The ATPase activity of TFIIH provides the energy necessary to drive the unwinding of the DNA during transcription initiation.
TFIIH plays a critical role in promoter clearance, transitioning RNA polymerase II from the initiation phase to the elongation phase of transcription.
It also participates in DNA repair processes, specifically in nucleotide excision repair, due to its helicase activity.
TFIIH's role is essential for ensuring that transcription initiation proceeds efficiently and accurately.
Additional Knowledge:
TFIID (option 1) is a key transcription factor involved in the recognition of the promoter and the binding of RNA polymerase II, but it does not have ATPase or helicase activity.
TFIIF (option 3) is involved in stabilizing the RNA polymerase and facilitating its interaction with the promoter, but it does not have the helicase or ATPase activities required for promoter opening.
TFIIE (option 4) helps in the recruitment of TFIIH and other transcription factors but does not possess ATPase or helicase activities.
