GTP-dependent tRNA ligase activity of PF0027 protein. (A) tRNA ligase activity using synthetic tRNA halves with different terminal structures. (Bottom) A combination of the 5′- and 3′-end structures. The reaction was carried out with 1 or 4 μg/mL purified PF0027 protein for 15 min at 37°C in the presence of 1 mM GTP. (B) GTP (1 mM)-dependent tRNA ligase activity. (C) Effect of various ribonucleotides and deoxyribonucleotides (1 mM each) on tRNA ligase activity. (D) Effect of GTP-analogs on tRNA ligase (4 μg/mL) activity. Synthetic tRNA halves bearing 2′,3′-cyclic phosphate and 5′-OH termini were used for Experiments C and D. (Arrowheads) Indicate the positions of ligated product (tRNA).
