Synthesis of Polyadenylate:Polyuridylate Catalyzed by Ribonucleic Acid Polymerase in the Absence of a Template

In the absence of any added template and after a variable lag period, ribonucleic acid polymerase catalyzes the polymerization of adenosine triphosphate and uridine triphosphate to polyadenylate and polyuridylate. The length of the lag period varies inversely with amount of enzyme and substrate present in the incubation mixture. The reaction requires Mn++; it does not occur if Mg++ is the only metal ion present. Unprimed synthesis of polyadenylate and polyuridylate is inhibited in the presence of polynucleotides, spermidine, guanosine triphosphate, and cytidine triphosphate. The product was characterized by nearest neighbor analysis, ultracentrifugal analysis, and thermal denaturation studies.