Effect of P2 oligo truncations on polymerization efficiency, with template T21. (A) Autoradiogram of polymerization products after PAGE separation. The concentrations of free magnesium correspond to the total magnesium concentration minus the concentration of NTPs (16 mM). The total magnesium concentration ranged from 20 mM to 200 mM. The number of nucleotides added to the primer are shown on the right. (B) Polymerization efficiency with the wild-type P2 oligo and 3′-truncated P2 oligos. The polymerization efficiency was quantified as the percentage of primers that were extended to full length of the template. Results for RNA P2 oligos (white) and DNA P2 oligos (gray) are shown. Error bars denote standard deviations from three experiments. A list with the efficiencies of more truncated P2 oligos is given in Supplemental Table S1.
