Question

The 3’- OH end of the branch point A makes the attack in splicing of an intron.

(a) True

(b) False

I had been asked this question by my college director while I was bunking the class.

My doubt is from Post-Transcriptional Modification in portion Gene Expression : Transcription Prokaryotes of Cytogenetics

Answer 1

The correct option is (b) False

The explanation: The 2’-OH of A base is seen to make this attack on the 5’ end of the intron at the phosphodiester bond while the original 3’-OH end of the A is still in the bonding with the phosphate. This makes a lariat structure.