Question

Mediator phosphorylates the _______-terminus of RNA polymerase II, stimulating progression to the __________ stage of transcription.

a) N; Initiation
b) C; Elongation
c) N; Elongation
d) C; Termination

Answer 1

The mediator phosphorylates the C-terminus of RNA polymerase II, aiding the transition from initiation to elongation during the transcription process. The correct option is (b) C; Elongation.

Step-by-step explanation:

The mediator phosphorylates the C-terminus of RNA polymerase II, which is a critical step in the process of transcription in eukaryotic cells. This phosphorylation event stimulates the progression from the initiation stage, where the transcription machinery assembles at the promoter, to the elongation stage, where mRNA synthesis occurs.

During elongation, the RNA polymerase II traverses the DNA template, synthesizing RNA from the 5' to 3' direction. The phosphorylation of C-terminal domain (CTD) of RNA polymerase II causes a structural change that allows transcription elongation to proceed efficiently. Therefore, the correct answer to this question is option (b) C; Elongation.