Give an account of post transcriptional modifications of a eukaryotic mRNA.

Post transcriptional modifications are the chemical alterations done to primary transcript of RNA.These modifications convert a gene into functional RNA.

1. In prokaryotes the primary transcript (hn-RNA) has both the non-coding introns inside the gene and the coding exons but they are non-functional.

2. Hence, Splicing takes place. In which introns are removed and exons are joined in definite order.

3. In Eukaryotes (hn-RNA) or primary transcript is absent so, slicing is not needed.

4. In such cases capping and tailing process takes place.

5. In capping Methyl Guanosine Triphosphate nucleotide is added to the 5’ end of hn-RNA known as cap structure.

6. In tailing Adenylate residues are added at the 3’ end of the RNA.

7. After the whole process hn-RNA is processed to form m-RNA or messenger RNA.

8. This m-RNA is transported out of the nucleus for translation.