Question

Arrange the different steps of transcription in the correct order:
(A) Transcription bubble formation
(B) Phosphorylation of CTD tail
(C) Recruitment of elongation factors
(D) Dephosphorylation of CTD tail
Choose the correct answer from the options given below:

• A. (A), (B), (C), (D)
• B. (A), (C), (B), (D)
• C. (B), (A), (D), (C)
• D. (C), (B), (D), (A)

Hint:

Understand the stages of transcription, including initiation, elongation, and termination, and the role of the CTD tail in RNA polymerase function.

Answer 1

The Correct Option is A

Transcription is the process by which genetic information in DNA is transcribed into RNA. The sequence of steps in transcription is as follows:
1. Transcription bubble formation (A): The process begins with the unwinding of DNA, forming a transcription bubble. This exposes the template strand for RNA synthesis.
2. Phosphorylation of CTD tail (B): The C-terminal domain (CTD) of RNA polymerase II undergoes phosphorylation. This modification is essential for transitioning the polymerase from the initiation phase to elongation.
3. Recruitment of elongation factors (C): During the elongation phase, various elongation factors are recruited to stabilize the transcription complex and assist RNA polymerase in synthesizing the RNA strand.
4. Dephosphorylation of CTD tail (D): At the end of transcription, the CTD tail is dephosphorylated, facilitating the termination of transcription and release of the RNA transcript.