title: Efficient metal-ion catalyzed template-directed oligonucleotide synthesis.
abstract: The Pb2+ and Zn2+ ions are efficient catalysts for the polycytidylic acid-directed polymerization of an activated guanylic acid derivative, guanosine 5'-phosphorimidazolide. The products include oligomers of 30 to 40 units in length. The nucleotide residues are predominantly 2'-5' linked when Pb2+ is the catalyst, and predominantly 3'-5' linked in the presence of Zn2+. The significance of these results in the context of the prebiotic evolution of RNA polymerase is discussed.
mesh_terms: D012321:DNA-Directed RNA Polymerases; D006150:Guanine Nucleotides / Q000138:chemical synthesis*; D006157:Guanosine Monophosphate / Q000031:analogs & derivatives / Q000138:chemical synthesis*; D007854:Lead; D010179:Pancreas / Q000201:enzymology; D011066:Poly C; D011131:Polyribonucleotides; D012260:Ribonucleases; D013698:Templates, Genetic; D015032:Zinc
chemical_list: D006150:Guanine Nucleotides; D011131:Polyribonucleotides; D007854:Lead; D011066:Poly C; C025339:guanosine 5'-phosphoimidazolide; D006157:Guanosine Monophosphate; D012321:DNA-Directed RNA Polymerases; D012260:Ribonucleases; D015032:Zinc