Question

In the case of group 1 RNA, which one of the following can’t attack?

(a) GMP

(b) GDP

(c) GTP

(d) ATP

The question was asked in a national level competition.

This key question is from Post-Transcriptional Modification topic in division Gene Expression : Transcription Prokaryotes of Cytogenetics

Answer 1

Right choice is (d) ATP

To elaborate: It is seen that in the case of group II auto splicing RNA the attack is made by the 3’-OH end of the ribose attached to the G base. It is immaterial whether its GMP, GDP or GTP. However, A base is not seen to attack in that case.