Figure 3.

Preferential unwinding of G4 DNA by Sgs1p. (A) Native gel analysis of products of unwinding of ³²P-labeled G4 DNA and HJ substrates by Sgs1p. Amounts of enzyme per reaction are indicated above the autoradiograph. Arrows indicate G4 and HJ substrates and single-stranded unwinding products (ss). (B) Kinetics of unwinding of ³²P-labeled G4 DNA and HJ, measured by native gel analysis. Products of reactions containing 5 ng of Sgs1p were incubated at 37°C for the times indicated. (C) Unwinding of ³²P-labeled G4 DNA in the presence of unlabeled G4 DNA or HJ. Reactions containing 5 ng of Sgs1p were incubated in the presence of the indicated molar excess of competitor and resolved on a native gel (left). Data are graphed on the right.