Figure 5.

Specificity of nucleotide incorporation opposite the template AP site. A ³²P-labeled 17mer primer was annealed right before the template AP site of four templates as shown. The templates differed by one base (underlined) 5′ to the AP site. DNA polymerase assays were then performed with 3.7 ng (46 fmol) human Pol ι using 50 fmol of the various AP site-containing templates as indicated. Polymerase reactions were carried out with dATP (A), dCTP (C), dTTP (T) and dGTP (G) individually or all four dNTPs (N₄). Quantitation of extended primers is shown at the bottom of the gels. DNA size markers in nt are indicated on the sides.