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#Unit 3. Fundamental Processes
The mechanism of pre-tRNA splicing differs in three fundamental ways from the mechanisms used by self-splicing introns and spliceosomes.
First, splicing of pre-tRNAs is catalyzed by proteins, not by RNAs. Second, a pre-tRNA intron is excised in one step thatentails simultaneous cleavage at both ends of the intron. Finally, hydrolysis of GTP and ATP is required to join the two tRNA halves generated by cleavage on either side of the intron.