Figure 4. RNA-dependent RNA and DNA polymerase activity of the 24–3 ribozyme.

Time course of the reaction using either NTPs (filled circles) or dNTPs (open circles), measuring the rate of single-nucleotide addition to a deoxynucleotide-terminated primer on template 1. The data were fit to a double exponential rise to maximum (r = 0.996 for RNA polymerization; r = 0.983 for DNA polymerization). Inset depicts the data over the first 2 min of the reaction. Reaction conditions: 100 nM ribozyme, 125 nM template, 125 nM primer, 2 mM NTPs or dNTPs, 200 mM MgCl₂, pH 8.3, 20°C.