Final answer:
The six general transcription factors (GTFs) for RNA polymerase II are TFIIA, TFIIB, TFIIE, TFIIF, TFIIH, and TFIID. Each of these transcription factors has a unique role in forming the transcription initiation complex necessary for the synthesis of mRNA.
Step-by-step explanation:
There are six general transcription factors (GTFs) involved in the initiation of transcription by RNA polymerase II. These transcription factors are critical for the recruitment and assembly of RNA polymerase II to the promoter regions of protein-coding genes, initiating the transcription of mRNA. The names of these basal transcription factors start with 'TFII' (indicating they are for RNA polymerase II) and are followed by a specific letter. The GTFs are:
TFIIA - Stabilizes TBP binding to the promoter and acts as an anti-repressor by displacing negative regulators.TFIIB - Binds to TBP and positions RNA polymerase at the start site of transcription.TFIIE - Attracts and regulates TFIIH.TFIIF - Stabilizes RNA polymerase interaction with TBP and TFIIB; also acts in start site selection.TFIIH - Contains helicase activity to unwind DNA and activates RNA polymerase by phosphorylation.TFIID - The first component to bind to DNA due to the presence of TBP (TATA-binding protein) and is responsible for recognizing and binding to the promoter.
Each factor plays a distinct role in the formation of the transcription initiation complex, ensuring that transcription is correctly initiated and mRNA synthesis occurs properly.