Question

Which is the 1^st enzyme in capping?

(a) Guanyltransferase

(b) RNA 5’ triphosphatase

(c) N7G methytransferase

(d) Guanul transferase

This question was posed to me in class test.

I want to ask this question from Post-Transcriptional Modification topic in chapter Gene Expression : Transcription Prokaryotes of Cytogenetics

Answer 1

Correct choice is (d) Guanul transferase

For explanation I would say: 1st the 5’ triphosphate group is removed by the phosphatase. Then the Gpp is added to it making it the G cap. Lastly the methyl transferase transfers the methyl group to the N7 position of the cap guanine.