Pol κ SNPs retain similar running start primer extension activity as WT pol κ on undamaged DNA templates (A, C) as well as both minor groove (B) and major groove (D, E) DNA adducts with the exception of R219I, R298H, and Y432S, which are markedly less active than WT on all templates. Time points are 0, 20, and 60 min for each variant; quantitation is reported in Table S1.