FIGURE 4.

XRCC1 stimulates ROS1 enzymatic activity. A, structure and length of the DNA substrates and products. M indicates 5-meC. B, purified ROS1 (18 nm) was incubated with a double-stranded oligonucleotide substrate (40 nm) containing three 5-meC:G pairs in the absence or presence of purified XRCC1 (18 nm). Reactions were stopped at the indicated times, and products were separated in a 12% denaturing polyacrylamide gel. C, product concentration either in the absence (diamonds) or in the presence (squares) of XRCC1 was quantified by fluorescence scanning. Values are mean ± S.E. from two independent experiments.