Fig. 2.

Poly(dT) template primer synthesis by primase using ATP or dATP. (A) ATP/dATP initiation competition assay. Each reaction contained 165 nM [γ-³²P] ATP and 10-fold dilutions of cold ATP or dATP ranging from 100 nM to 1 mM. Selected product sizes are indicated on the left. (B) ATP/dATP elongation competition assay. Reactions from lanes 1–6 contained 33 nM [α-³²P] ATP, 10 µM cold ATP, and 10-fold dilutions of cold dATP ranging from 100 nM to 1 mM; reactions from lane 7–12 contained 33 nM [α-³²P] dATP, 10 µM cold dATP, and 10-fold dilutions of cold ATP ranging from 100 nM to 1 mM. (C) ATP/dATP elongation competition assay followed by alkaline treatment. ATP:dATP concentration ratios are indicated at the bottom of the gel, where “1” represents a concentration of 10 µM.