Question

What is the correct sequence of events leading to successful RNA splicing?

I. cut is made at 3' splice site
II. cut is made at 5' splice site
III. 5' end of intron attaches to branch point
IV. two exons are spliced together
V. lariat is formed
VI. intron is released

Answer 1

II-V-III-I-VI-IV

Step-by-step explanation:

1. In RNA splicing the mRNA is first cut at the 5' splice site, present at the 5' side of mRNA

2. Then the intron folds back on itself and forms a lariat

3. And then the guanine nucleotide in the consensus sequence at the 5' splice site bonds with the adenine nucleotide (A) at the branch point through a transesterification reaction . And both the 5' cleavage and lariat formation occur in a single step

4. After that a cut is made at the 3' splice site that cause free of the intron.

5. Then the intron is released as in form of a lariat.

6. And then finally the two exons are spliced together and splicing has done.