Name the factors for RNA polymerase enzymes which recognize the start and termination signals on DNA for transcription process in Bacteria

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Solution

Dear Student,
RNA polymerase is only capable of catalysing the process of elongation. It associates transiently with initiation-factor (σ) and termination-factor (ρ) to initiate and terminate the transcription. Association with these factors alter the specificity of the RNA polymerase to either initiate or terminate.

Initiation-factor (σ) or sigma is a protein and transcription initiation factor. It enable RNA polymerase binding to the promoter. Different types of sigma factors are specific for transcribing different genes.

A ρ factor (Rho factor) is a prokaryotic protein required to release the newly made (nascent) RNA from transcription complex.

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Similar questions

The paragraph below gives a description about transcription. Which is the correct description among them? (a) Enzyme involved in transcription is RNA polymerase-II, which consists of 5 polypeptides α, β, β’, σ and ω. Core enzyme recognizes promoter site while σ factor takes part in chain elongation. (b). Initiation starts with help of core enzymes of RNA polymerase enzyme. (c) Elongation is done by σ factor, which moves along the sense strand. (d) In prokaryotes, termination is done by rho factor while in eukaryotes; poly A tail is responsible for termination at 3’.

Q. Read the following statements regarding transcription.
1. RNA polymerase initiates the process of transcription with the help of sigma factor.
2. RNA polymerase also facilitates opening of the DNA double helix in prokaryotes.
3. Transcription requires primer
4. In bacteria, there are three types of RNA polymerases.
How many of the above statements are incorrect?

Q. In transcription, against which strand of DNA does the DNA dependent RNA polymerase catalyse the process?

Q. In eukaryotic transcription
(A) RNA polymerase II is responsible for the transcription of hnRNA
(B) The transcription factors recognise the promoter
(C) The core promoter determines the frequency of initiation
(D) Transcription termination by genes transcribed by RNA polymerase I are similar to rho-dependent prokaryotic termination

Choose the correct option

Q. How many of the following statements are correct ?

A. DNA dependent DNA polymerase requires DNA primer for initiating replication but DNA dependent RNA polymerase does not require any primer for transcription.

B. DNA dependent DNA polymerase requires RNA primer for initiating replication but DNA dependent RNA polymerase does not require any primer for transcription.

C. During replication, unwinding of DNA double helix forms a fork-like structure called replication fork.

D. During transcription, unwinding of the DNA double helix by DNA dependent RNA polymerase forms a transcription bubble.

E. During transcription, unwinding of DNA double helix by DNA dependent RNA polymerase forms a transcription fork.

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