FIGURE 4.

RPA stimulates FANCJ helicase activity on the thymine glycol substrates in a strand-specific manner. Helicase reaction mixtures contained 3 nm RPA, 1.2 nm FANCJ, and 0.5 nm forked DNA substrate with thymine glycol in the bottom strand (nontranslocating) (TG-B) (A), top strand (translocating) (TG-C) (B), or neither strand (C) under standard helicase assay conditions as described under “Materials and Methods” for the indicated times from 0 to 32 min. Quantitative analyses of FANCJ helicase data are shown (open squares, FANCJ; filled squares, FANCJ + RPA).