Question

Which of the following is not a normal processing step of the tRNA?

(a) The 3’ end U is replaced by CCA

(b) The Purines are methylated and isopentyl groups are transferred to them

(c) The 3’ OH is methylated

(d) U bases at specific sites are converted to pseudo uridine, ribo thimidine or dihydrouridine

I had been asked this question in a job interview.

My query is from RNA Processing Control in section Regulating Gene Expression in Eukaryotes of Cytogenetics

Answer 1

The correct choice is (c) The 3’ OH is methylated

The best explanation: The 2’-OH groups of some bases are modified in the tRNA and not the 3’-OH. White the remaining modifications of the tRNA transcript are necessary.