A. Substrates used to test re-initiation of unwinding by RecBCD.
B. Stopped-flow experiments were performed by mixing pre-incubated RecBCD and DNA Substrate XVII (18.75 and 25 nM, respectively) in Buffer M (250 mM NaCl) in a 1:10 volumetric ratio with ATP (1 mM) and heparin (8 mg/mL) in buffer M (8 mM NaCl) yielding the final concentrations listed above and a final NaCl concentration of 30 mM at 25°C. Cy3 fluorescence was excited at 505 nm, and Cy3 fluorescence (green) was monitored at 570 nm and Cy5 fluorescence (red) was monitored at > 665 nm.
C. Cy3 fluorescence traces for experiments as performed in panel B, at 1 mM ATP (dark blue), 200 μM ATP (pink), 40 μM ATP (light blue), and no ATP (gray).
D. Cy3 fluorescence traces for experiments as performed in panel B at 1 mM ATP using Substrate XVI (red), XVII (blue), or XVIII (orange).