Question

The core part of RNA polymerase is responsible for catalysing which step of transcription?

• A. Initiation
• B. Elongation
• C. Termination
• D. All the three steps

Answer 1

The correct option is B Elongation

Core part of RNA polymerase consists of 4 sub unit’s i.e 2α, 1 β and 1β’ subunit, each of the subunit have specific functions such as:

2α - These bind to regulatory proteins

1 β - It binds to DNA template

1β’ - It binds to RNA nucleotides

Elongation process starts when sigma (σ) factor disassociates with RNA polymerase thus allowing the core enzyme to proceed along with the DNA template in 5’-3’ direction. Core enzyme alone is responsible for catalysing the elongation step of transcription.

Sigma (σ) factor is the protein which is responsible for initiating transcription whereas rho (ρ) factor will take care of terminating the transcription process.