Figure 5.
Processing of the 5′-dRP-containing BER intermediate in mitochondrial extracts. (A) Illustrations of the single-nucleotide gapped DNA substrate before (17Uracil) and after (17dRP) UDG treatment and the reaction product after 5′-dRP group removal (17-mer). In panels B and C, lane 1 is the minus enzyme control, and lane 2 is the reference reaction product for 5′-dRP removal by purified pol β. (B) Lanes 3–7 and 8–12 are the reaction products observed in mitochondrial extracts from wild-type and Pol β−/− cells, respectively, and correspond to time points 5, 15, 30, 45 and 60 min. (C) Lanes 3–7 and 8–12 are the reaction products observed in mitochondrial extracts from APTX−/− and APTX−/−Pol β−/− cells, respectively, and correspond to time points 5, 15, 30, 45 and 60 min. A representative gel of three independent experiments is presented.