Figure 2.

Two modes of mismatch extension by hPolκ. (Left) In direct mismatch extension, following a primer-terminal mispair, the incoming dCTP (indicated by the curved arrow) base pairs with the correct templating base G. (Right) In extension by misalignment, the C · C mispair realigns so that the template C becomes extrahelical and the primer-terminal C pairs with the next template base G. This is followed by the pairing of the incoming dTTP (indicated by the curved arrow) with the subsequent complementary template base.