RNA polymerase needs a subunit to initiate transcription that is not needed for transcript elongation.What is the subunit?
A)Mg²⁺
B)rho
C)sigma
D)the holoenzyme

Question

Quizplus · Accepted Answer

Sigma factor is a subunit of RNA polymerase that is required for initiation of transcription. It recognizes specific promoter sequences in DNA and helps to position RNA polymerase at the start site for transcription. After the initiation phase, sigma factor dissociates from RNA polymerase and elongation of transcripts continues without it. Therefore, sigma factor is not required for transcript elongation.

RNA Polymerase Needs a Subunit to Initiate Transcription That Is