Can attenuation occur in eukaryotes?
Can attenuation occur in eukaryotes?
Prokaryotes commonly use attenuation as a mechanism to control gene expression, but eukaryotes do not. In prokaryotes transcription and translation are coupled. This makes attenuation possible.
Why does attenuation only occur in prokaryotes?
Attenuation is made possible by the fact that in prokaryotes (which have no nucleus), the ribosomes begin translating the mRNA while RNA polymerase is still transcribing the DNA sequence. This allows the process of translation to directly affect transcription of the operon.
How does termination occur in eukaryotes?
Translation termination in eukaryotes occurs in response to a stop codon in the ribosomal A-site and requires two release factors (RFs), eRF1 and eRF3, which bind to the A-site as an eRF1/eRF3/GTP complex with eRF1 responsible for codon recognition.
Why is the TRP attenuation mechanism unique to prokaryotes?
The concentration of tryptophan controls transcription of the trp operon. Because transcription and translation occur simultaneously in bacteria, changes affecting one process automatically affect the other. This relationship can be exploited to provide a gene regulatory mechanism that is unique to prokaryotes.
Why do eukaryotes not use attenuation?
1). There is no coupling of transcription and translation in eukaryotic cells as in bacterial cells. Consequently, ribosome movement and arrest cannot modulate attenuation.
Why are eukaryotes not regulated by attenuation?
(In eukaryotes, there is no exact equivalent of attenuation, because transcription occurs in the nucleus and translation occurs in the cytoplasm, making this sort of coordinated effect impossible.) Yet another layer of prokaryotic regulation affects the structure of RNA polymerase, which turns on large groups of genes.
Why is there no attenuation in eukaryotes?
The attenuation is the regulatory process that occurs in the prokaryotic cells. In the attenuation process, the ribosome will stop in the region of the leader sequence. This will also stop further transcription. This process cannot occur in the eukaryotes as the process of transcription occurs in the nucleus.
What are the key differences between transcription in eukaryotes and prokaryotes?
Prokaryotic vs Eukaryotic Transcription
| Prokaryotic Transcription | Eukaryotic Transcription |
|---|---|
| Doesn’t require any proteins or other factors for the initiation of transcription | Requires proteins known as transcription factors for the initiation. |
How is translation terminated in prokaryotes?
Termination. Termination of translation occurs when a nonsense codon (UAA, UAG, or UGA) is encountered. Upon aligning with the A site, these nonsense codons are recognized by protein release factors that resemble tRNAs.
What level of regulation do eukaryotes possess that prokaryotes do not?
transcription initiation. What level of regulation do eukaryotes possess that prokaryotes do not? Transport of RNA out of the nucleus.
How attenuation regulates protein synthesis in prokaryotic cells?
Attenuation occurs by a mechanism by which rapid translation of the nascent transcript causes the termination of transcription. As the transcript is being produced, if ribosomes attach and rapidly translate the transcript, a secondary structure is generated in the mRNA that is a termination signal for RNA polymerase.
What is the function of antitermination in prokaryotes?
Jump to navigation Jump to search. Antitermination is the prokaryotic cell’s aid to fix premature termination of RNA synthesis during the transcription of RNA.
What are the three differences between prokaryotes and eukaryotes?
Eukaryotes: What Are the Differences? 1 Understanding Cells and Cell Membranes. The cell is a fundamental component of our modern definition of life and living things. 2 Prokaryotes. Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles. 3 Eukaryotes.
What is antitermination and how does it occur?
It occurs when the RNA polymerase ignores the termination signal and continues elongating its transcript until a second signal is reached. Antitermination provides a mechanism whereby one or more genes at the end of an operon can be switched either on or off, depending on the polymerase either recognizing or not recognizing the termination signal.
What are prokaryotes made of?
Prokaryotes are organisms made up of cells that lack a cell nucleus or any membrane-encased organelles. Eukaryotes are organisms made up of cells that possess a membrane-bound nucleus (that holds genetic material) as well as membrane-bound organelles.
