FIG. 4.

Characterization of binding of Hop1 protein to G4 DNA. Reactions were carried out in a standard assay buffer (20 μl) containing 10 pmol of TP G4 DNA and 0.5 μM Hop1 protein, plus the indicated additional treatments, as described in Materials and Methods. (A) Kinetics of Hop1 protein binding to G4 DNA with no added constituents. (B) Complex formation with G4 DNA in the absence or presence of zinc (0.1 mM), EDTA (5 mM), dithiothreitol (DTT; 10 mM), ATP (5 mM), MgCl₂ (10 mM), proteinase K (0.2 mg/ml), or SDS or glycerol at the indicated concentrations. (C) Effect of NaCl added at the indicated concentrations. TP(G4) and M denote G4 DNA prepared from TP oligonucleotide and its unfolded constituent monomer, respectively.