FIGURE 6.

hnRNP-U stimulation of NEIL1 activity for excision of 5-OHU from various DNA substrates. A, a 5-OHU-containing 51-mer oligonucleotide (25 nm) was used alone (single-stranded) or annealed with complementary strands to generate duplex, bubble, or fork structures (supplemental Table S1) for use as NEIL1 substrate. Lanes 2–5, WT NEIL1 (1 nm; lane 2) alone or after preincubation of the DNA with various levels of hnRNP-U (0.1, 0.5, 1 nm; lanes 3–5). S and P indicate uncleaved substrate and cleaved product, respectively. Other details are described under “Experimental Procedures.” B, comparison of hnRNP-U stimulation with various repair substrates. Error bars indicate S.D.