In: Biology
After the synthesis of RNA from DNA via transcription, RNA is processed in a number of ways before it is released from the nucleus. What are the steps to RNA processing?
Generally in prokaryotes RNA Processing is not too much because of no nucleus. And in Eukaryotes RNA processing involves many steps.
A freshly synthesized RNA transcript is pre-mRNA after Processing it is called mRNA(messanger RNA).
The various steps involved in RNA processing are as follow:-
Splicing - It is the removal of introns(non-coding regions) and joining of exons(coding regions).
Capping - capping is adding of 7-methylguanosine triphosphate to the 5′ end of the growing transcript by a 5′-to-5′ phosphate linkage. This process prevent nascent RNA from degradation.
Tailing - tailing is adding of poly A tail at the 3' end. An enzyme called poly (A) polymerase (PAP) is part of the same protein complex that cleaves the pre-mRNA and it immediately adds a string of approximately 200 A nucleotides, called the poly (A) tail, to the 3′ end of the just-cleaved pre-mRNA. The poly (A) tail protects mRNA from degradation and helps in the export of the mature mRNA to the cytoplasm