Final answer:
TFIIH is the only general transcription factor with enzymatic activity, involved in unwinding DNA and phosphorylating RNA polymerase II during the initiation of eukaryotic gene transcription.
Step-by-step explanation:
The only general transcription factor known to have enzymatic activity is TFIIH. This basal transcription factor is crucial for the transcription of a eukaryotic gene by RNA polymerase II. TFIIH has several functions including the unwinding of DNA at the transcription start site and the phosphorylation of RNA polymerase II, which is necessary for the initiation of transcription. These activities are a part of the transcription initiation complex formation where various TFII factors like TFIID, TFIIB, TFIIE, TFIIF, and TFIIH systematically bind to the DNA template and play roles in the recruitment and stabilization of RNA polymerase II to begin mRNA synthesis.
The only general transcription factor known to have enzymatic activity is TFIIH (b).
TFIIH plays a crucial role in eukaryotic transcription by unwinding the DNA helix and phosphorylating the C-terminal domain of RNA polymerase II, which is necessary for transcription initiation and elongation.
For example, TFIIH has helicase activity, meaning it can separate the DNA strands to create a transcription bubble. It also has kinase activity, which allows it to phosphorylate specific proteins involved in transcription.