What is the Difference Between Prokaryotic and Eukaryotic mRNA?

The main differences between prokaryotic and eukaryotic mRNA are as follows:

1. Structure: Prokaryotic mRNA is polycistronic, meaning it can code for multiple proteins, while eukaryotic mRNA is monocistronic, meaning it codes for only one protein.
2. Transcription: In eukaryotes, transcription occurs in the nucleus, whereas in prokaryotes, transcription takes place in the cytoplasm.
3. Transcription Factors: Eukaryotes use transcription factor proteins in transcription, while prokaryotes use sigma factors.
4. Ribosome Binding: Prokaryotic mRNA has a Shine-Dalgarno sequence for ribosome binding, while eukaryotic mRNA has a 5' cap and poly-A tail for protection and ribosome binding.
5. First Amino Acid: The first amino acid in prokaryotic mRNA is formylmethionine, while in eukaryotic mRNA, it is methionine.
6. Lifespan: Prokaryotic mRNA has a shorter lifespan, while eukaryotic mRNA has a longer lifespan.

In summary, prokaryotic and eukaryotic mRNA differ in their structure, transcription process, ribosome binding, first amino acid, and lifespan.

Comparative Table: Prokaryotic vs Eukaryotic mRNA

Here is a table comparing the differences between prokaryotic and eukaryotic mRNA:

• Structure: Prokaryotic mRNA is often polycistronic, meaning multiple genes are transcribed into a single mRNA molecule. In contrast, eukaryotic mRNA is monocistronic, with each mRNA molecule encoding for a single gene.

• Translation: In prokaryotes, translation and transcription occur almost simultaneously, making the process synchronous. In eukaryotes, transcription occurs prior to translation, with translation taking place in the cytoplasm, making the process asynchronous.

• Location: Prokaryotic mRNA is found in the cytoplasm, while eukaryotic mRNA is found in the nucleus.

• Cap Initiation: Prokaryotic mRNA is cap-dependent, while eukaryotic mRNA is both cap-dependent and cap-independent.

• Stability: Prokaryotic mRNA is unstable, with a lifespan of a few seconds to 2 minutes. Eukaryotic mRNA is more stable, with a lifespan of a few hours to days.

• Occurrence: Prokaryotic translation occurs throughout the cell's life cycle, while eukaryotic translation occurs during the G1 and G2 phases of the cell cycle.

• Ribosomes: Prokaryotic ribosomes have a 70S subunit size, while eukaryotic ribosomes have an 80S subunit size.