Question

Choose the correct answer from the alternatives given :
Which of the following steps in transcription is catalyzed by RNA polymerase?

• A. Initiation
• B. Elongation
• C. Termination
• D. All of the above

Answer 1

The correct option is D All of the above

There is single DNA-dependent RNA polymerase that catalyses transcription of all types of RNA in bacteria. RNA polymerase binds to promoter and initiates transcription (Initiation). It uses nucleoside triphosphates as substrate and polymerises in a template dependent fashion following the rule of complementarity. It somehow also facilitates opening of the helix and continues elongation. Only a short stretch, of RNA remains bound to the enzyme. Once the polymerases reaches the terminator region, the nascent RNA fall off, so also the RNA polymerase. This results in termination of transcription. The RNA polymerase is only capable to catalysing the process of elongation. It associates transiently with initiation-factor (σ) and termination-factor (ρ) to initiate and terminate the transcription respectively. Association with these factors alter the specificity of the RNA polymerase to either initiate or terminate.

So, the correct answer is 'All of the above'.