The nonenzymatic template-directed ligation of oligonucleotides

Abstract. The nonenzymatic template-directed ligation of oligonucleotides containing 2', 3'-cyclic phosphate was investigated in the presence of divalent cations. Ligation of the oligonucleotides readily occurred in the presence of Mg²⁺, Mn²⁺, Co²⁺, Zn²⁺, Pb²⁺. Efficacy of the metal ion catalysts inversely correlated with pKa values of the metal-bound water molecules. The intermolecular transesterification reaction yielded at least 95metal ion. Relatively high reaction yields (up to 15fragmentation to oligonucleotides with 2',3'-cyclic phosphates, followed by reactions of those oligonucleotides could provide a source of new RNA molecules under prebiotic conditions.