Do bacteria and eukaryotes terminate transcription the same way?

Not entirely. Bacteria use intrinsic hairpin-driven and Rho-dependent termination, while eukaryotic termination of protein-coding genes is tied to cleavage and polyadenylation.

What is a terminator?

A DNA sequence whose transcript or context signals the polymerase to stop; in bacteria it often encodes an RNA hairpin followed by a uridine-rich stretch.

Transcription Termination

How RNA polymerase recognises the end of a transcription unit, stops synthesis, and releases the completed RNA and itself from the template.

Definition

Transcription termination is the process by which RNA polymerase ceases RNA synthesis at the end of a transcription unit, releasing both the completed transcript and the polymerase from the DNA template in response to specific termination signals.

Scope

This topic covers the signals and mechanisms that end transcription. In bacteria it contrasts intrinsic (factor-independent) termination, driven by an RNA hairpin and a poly-uridine tract, with Rho-dependent termination. In eukaryotes it relates termination of protein-coding genes to 3'-end cleavage and polyadenylation. It treats termination as the closing step of transcription; the maturation of the released transcript is covered under RNA processing.

Core questions

What signals tell RNA polymerase to stop?
How does an RNA hairpin cause factor-independent termination in bacteria?
What does the Rho factor do in Rho-dependent termination?
How is termination of eukaryotic genes linked to 3'-end processing?

Key theories

Intrinsic (factor-independent) termination: A self-complementary sequence in the nascent RNA folds into a stable hairpin that, followed by a run of uridines, destabilises the elongation complex and causes the polymerase to release the transcript without needing accessory proteins.
Factor-dependent termination: In Rho-dependent termination, the Rho protein binds the RNA and translocates along it to catch and dissociate the polymerase, while eukaryotic termination is coupled to cleavage and polyadenylation of the transcript.

Mechanisms

In bacterial intrinsic termination, transcription of a GC-rich inverted repeat produces an RNA hairpin just upstream of a uridine-rich segment; the weak rU–dA hybrid plus the hairpin destabilise the paused elongation complex, releasing polymerase and RNA. In Rho-dependent termination, the Rho helicase loads onto the RNA at a recognition site and moves toward the polymerase, using its activity to dissociate the complex at a downstream pause. In eukaryotic protein-coding genes, recognition of the polyadenylation signal triggers cleavage of the transcript and, through associated factors, eventual release of the polymerase.

Clinical relevance

Failure to terminate correctly can produce aberrant or read-through transcripts implicated in disease, and termination machinery is studied in relation to gene regulation; offered as significance, not clinical guidance.

History

Studies of bacterial transcription in the 1960s and 1970s distinguished intrinsic from Rho-dependent termination, and later work linked eukaryotic termination to the 3'-end processing machinery, producing the dual picture taught today.

Key figures

Jeffrey Roberts
Peter von Hippel

Seminal works

watson2013
lodish2016

Frequently asked questions

Do bacteria and eukaryotes terminate transcription the same way?: Not entirely. Bacteria use intrinsic hairpin-driven and Rho-dependent termination, while eukaryotic termination of protein-coding genes is tied to cleavage and polyadenylation.
What is a terminator?: A DNA sequence whose transcript or context signals the polymerase to stop; in bacteria it often encodes an RNA hairpin followed by a uridine-rich stretch.