Question

What is the second step in POL II initiation (mRNA)?

1) Binding of TFIID to the TATA box
2) Recruitment of other general transcription factors
3) Formation of the pre-initiation complex
4) Promoter clearance

Answer 1

The second step in RNA polymerase II initiation is the recruitment of additional general transcription factors after TFIID binds to the TATA box, leading to the formation of the transcription initiation complex.

Step-by-step explanation:

The second step in RNA polymerase II initiation of mRNA transcription involves the recruitment of other general transcription factors, following the binding of TFIID to the TATA box. These additional transcription factors include TFIIA, TFIIB, TFGIIE, TFIIF, and TFIIH. Together, they form the transcription initiation complex with RNA polymerase II. Once the complex is formed, the RNA polymerase is phosphorylated, which allows for promoter clearance and the start of mRNA synthesis. This complex and ordered assembly process is necessary to stabilize the pre-initiation complex and ensure that transcription initiates accurately and efficiently at the appropriate starting point in the DNA template.