Question

Which of the following steps in transcription is catalysed by RNA polymerse?

Options

• Elongation

• Initiation

• Termination

• All of the above

Answer 1

Elongation

Explanation:

While RNA polymerase is involved in all three stages of transcription, it is capable of catalysing elongation on its own. During this phase, the enzyme moves along the DNA template strand and links ribonucleotides together to build the growing RNA chain. For the other two stages, initiation and termination, the core enzyme requires the help of specific transient factors. It must associate with the sigma (σ) factor to recognise the promoter and initiate transcription, and it requires the rho (ρ) factor (in many bacteria) to recognise the stop signal and terminate the process.