FIGURE 2.

FANCJ is an ATP-dependent G4 unwinding enzyme. A, recombinant FANCJ protein was expressed and purified from Sf9 cells. Protein was resolved by SDS-PAGE and visualized using simply blue stain (Invitrogen). B, FANCJ unwinds G4 DNA substrates. ³²P-End-labeled OX1 G4 DNA was incubated with increasing concentrations of FANCJ (as indicated) in the presence of ATP. Unwinding of G4 DNA is detected by the production of a single-stranded oligonucleotide DNA product (S.S.). Reaction products were analyzed by polyacrylamide gel electrophoresis and visualized using a PhosphorImager (GE Healthcare).