What are the two types of termination in transcription?

There are two major termination strategies found in bacteria: Rho-dependent and Rho-independent. In Rho-dependent termination, the RNA contains a binding site for a protein called Rho factor.

What are the two important elements of an intrinsic transcription terminator?

Thus, we will instead consider what is known about these two aspects of intrinsic termination mechanisms: structural changes in the nucleic acid scaffold and conformational changes in RNAP.

What is the termination of transcription?

Transcription termination occurs when a transcribing RNA polymerase releases the DNA template and the nascent RNA. Termination is required for preventing the inappropriate transcription of downstream genes, and for recycling of the polymerase.

What is Rho dependent and rho independent termination?

The key difference between Rho dependent and Rho independent termination is that in Rho dependent termination, Rho factor binds with the transcript and terminates transcription by breaking hydrogen bonds between the template and the transcript, while Rho independent termination terminates the transcription by producing …

What mRNA structure signals termination in prokaryotic cells through transcription?

Transcription termination is signaled by a stem-loop structure that forms by complementary base pairing between two specific sequences of the growing Trp mRNA chain (Figure 6.11).

Where does RNA polymerase II stop transcribing?

In contrast to polyadenylation, termination of transcription occurs where Pol II is released from the DNA template over a range of about 200 (yeast) to 1500 (humans) nt downstream of the PAS [48,49].

What does intrinsic transcription termination require?

Intrinsic termination of transcription in Escherichia coli involves the formation of an RNA hairpin in the nascent RNA. This hairpin plays a central role in the release of the transcript and polymerase at intrinsic termination sites on the DNA template.

What causes intrinsic transcription termination?

Intrinsic, or rho-independent termination, is a process in prokaryotes to signal the end of transcription and release the newly constructed RNA molecule. In prokaryotes such as E. coli, transcription is terminated either by a rho-dependent process or rho-independent process.

What mechanism is involved in the termination of an mRNA molecule?

Transcription termination occurs in a reaction coupled to RNA 3′-end processing. Most eukaryotic mRNA precursors are cleaved in a site-specific manner in the 3′-untranslated region, followed by polyadenylation of the upstream cleavage product. A large number of proteins is involved in these reactions.

What process describes the removal of portions of mRNA after transcription to produce mRNA consisting of regions to be translated?

Most pre-mRNA molecules have sections that are removed from the molecule, called introns, and sections that are linked or together to make the final mRNA, called exons. This process is called splicing.

What is Rho dependent termination of transcription?

Rho-dependent termination occurs by binding of Rho to ribosome-free mRNA, C-rich sites being good candidates for binding. Rho’s ATPase is activated by Rho-mRNA binding, and provides the energy for Rho translocation along the mRNA; translocation requires sliding of the message into the central hole of the hexamer.

What does the Rho-independent mechanism of transcription termination require?

Escherichia coli protein Rho is required for the factor-dependent transcription termination by an RNA polymerase and is essential for the viability of the cell. It is a homohexameric protein that recognizes and binds preferably to C-rich sites in the transcribed RNA.