Figure 2.

Template requirements for stable interaction with RdRp. (A) Schematic of proscripts containing 5′ truncations of the template. The initiation site is denoted with an arrow. Proscripts containing the +1 c/g mutation (circled) are unable to direct RNA synthesis. The names and I₅₀ values for each construct are listed to the sides. (B) Determination of I₅₀ values. The amount of activity from the −20/15 proscript directing synthesis of a 15-nt product was measured in the presence of increasing amounts (up to 10-fold molar excess, 250 nM) of competitor templates. The I₅₀ value was determined as the concentration of competitor needed to reduce the 15-nt product from 25 nM of the −20//15 proscript by 50%. The identities of the various proscript competitors are labeled to the right. Data points represent the mean of at least three independent experiments with the SD expressed as error bars.