Hydrolyzes RNA 2',3'-cyclic phosphodiester to an RNA 2'-phosphomonoester. In vitro, ligates 5' and 3' half-tRNA molecules with 2',3'-cyclic phosphate and 5'-hydroxyl termini, respectively, to the product containing the 2'-5' phosphodiester linkage. Ligase activity requires GTP, but GTP hydrolysis is not required for the reaction, which is reversible. Ligase activity is weak compared to the phosphodiesterase activity. a 3'-end 2',3'-cyclophospho-ribonucleotide-RNA + H2O = a 3'-end 2'-phospho-ribonucleotide-RNA + H(+) Belongs to the 2H phosphoesterase superfamily. ThpR family.