Binding behavior of PhaR to target DNAs. (A) Typical time courses of the frequency changes of the phaP promoter region (curve a), phaR promoter region (curve b), and 0-site DNA immobilized on a QCM oscillator (curve c), in response to the addition of PhaR. The arrow indicates the time of enzyme injection. [PhaR] = 3.75 nM, [DNA] = 19 ± 1 ng (0.55 ± 0.02 pmol) cm-2 on a QCM, in 10 mM HEPES buffer solution (pH 7.4) containing 150 mM NaCl and 0.001% Tween 20 at 25°C. (B) Saturation binding of PhaR to each sequence of phaP promoter region DNA (curve a and ●), phaR promoter region DNA (curve b and ×) and 0-site DNA immobilized on to a QCM (curve c and □). Each curve was fitted with a sigmoid curve.