Figure 5.

Measurement of helicase activity under single turnover conditions. The single turn over kinetics for measuring unwinding activity of 1 nm full-length and N terminus deleted Pif1 helicase activity was assessed in the presence of a protein trap (T₅₀) and DNA trap (unlabeled 45mer complementary to displaced strand) over 6 time points (0”, 30”, 1', 2', 3', and 4') in the presence of 5 nm IR labeled (A) DNA fork and (B) RNA fork. Data from the analysis was fit to a first-order reaction (A{1-exp[−(k_u × X)), in which A is the amplitude of the reaction, k_u is the apparent rate constant of unwinding, and X is time. Black line with open squares represents Pif1-FL and dotted black lines with filled squares represents acetylated form of Pif1-FL. Red line with open triangles represents Pif1ΔN and dotted red lines with filled triangle represents acetylated form of Pif1ΔN. Values are represented as mean ± S.E. of at least three independent experiments.