Figure 5.

A proposed model for the incorporation of I34 into human tRNAs. Leader and trailer sequences on pre-tRNAs are shown in light grey colour. I34 modification is depicted as a light orange circle at position 34 of the tRNA; while other tRNA modifications are shown as red asterisks. Amino acids on mature tRNAs are illustrated as a blue circle at the 3′-end of the tRNA molecule. Question marks indicate speculative processes. Brown arrows indicate hetADAT activity on different tRNA substrates. Nucleobase pairing for I34 (purple chemical structure) and A34 (blue chemical structure) are shown. See main text for full details.