6.5.1.B3	GTP	the activity is dependent on GTP. The GTP structure is important but GTP hydrolysis is not required for the reaction, and GTPgammaS enhances the tRNA ligation activity. GTP is specific and indispensable for the tRNA ligation reaction. ATP, CTP, UTP, dATP, and dGTP cannot substitute for GTP. Neither GDP nor GMP enhance the ligation activity	723755