Figure 5.

Mismatch extension by human Polκ. (A) Various primers labeled at their 5′-ends with ³²P as indicated by asterisks were annealed to the 30mer template, generating 12 possible mismatches at the primer 3′-ends. (B) Mismatched substrates were incubated with (Polκ, +) or without (Polκ, –) DNA Polκ (4 ng, 40 fmol) under standard polymerase assay conditions. Lanes 25 and 26, the 30mer template was annealed with the 17mer primer 5′-*CGCGCGGCCTCCGGTTA-3′ generating a correct T–A base pair at the primer 3′-end. DNA size markers (in nucleotides) are indicated on the sides. It should be noted that the primers in the T–C (lane 2) and T–A DNA substrates (lane 26) are 4 nt longer at the 5′-end than other primers.