Question

1. What are the regulatory sequences in prokaryotes & eukaryotes for transcription?

2. What are the proteins involved in transcription in prokaryotes & eukaryotes?

3. What are the modifications for transcription in prokaryotes & eukaryotes

Answer 1

1. Regulatory sequences

• In prokaryotetic cell - Promoter, operator and enhancer regions regulate the transcription of the gene into an mRNA.
• In eukaryotic cell - RNA polymerase II have two core promoter elements, the TATA box and the Inr sequence, that serve as specific binding sites for general transcription factors.Other cis-acting sequences serve as binding sites for a wide variety of regulatory factors that control the expression of individual genes.

2. Proteins involved in transcription

• In prokaryote - RNA polymerase to transcribe all of their genes.
• In eukaryotes -

1. RNA polymerase I transcribes rRNA genes.
2. RNA polymerase II transcribes all of the protein-coding genes.
3. RNA polymerase III transcribes rRNA, tRNA, and small nuclear RNA genes.

3. Modifications for transcription

• In prokaryotes - The modifications such as 5' capping, 3' polyadenylation, and RNA splicing are not occurs.
• In eukaryotes - These modifications are 5' capping, 3' polyadenylation, and RNA splicing, which occur in the cell nucleus before the RNA is translated.