Final answer:
TFIIH is involved in transcription initiation, where it contributes to the formation of the preinitiation complex and the phosphorylation of RNA polymerase II.
Step-by-step explanation:
TFIIH is involved in transcription initiation. As a basal transcription factor for RNA polymerase II, TFIIH plays a crucial role in the process of eukaryotic transcription. It is part of the transcription initiation complex that forms on the DNA template prior to RNA synthesis.
TFIIH has helicase activity, which is important for unwinding the DNA to allow template strand reading, and it also plays a role in phosphorylating the RNA polymerase II enzyme, a modification necessary to transition from initiation to elongation during mRNA synthesis.
The other transcription factors, together with TFIIH, contribute to the formation of the preinitiation complex, which facilitates the recruitment of RNA polymerase II to the gene's promoter. Once the RNA polymerase II is properly positioned and modified by phosphorylation, transcription of the gene into mRNA can begin.