Unwinding of Okazaki fragment-like structures. ( A ) Time course of unwinding of R8D:M2. ( B ) Time course of unwinding of R4D:M2. ( C ) Time course of unwinding of R1D:M2. Unwinding of either construct by 28 nM WRN (left) or DHX9 (right) and 1 nM of substrate is shown in a 10-min time scale. Triangle represents, heat-denatured control; NE, no enzyme. 8R, 4R and 1R indicate the numbers of ribonucleotides at the 5′ ends. ( D ) Quantification of unwinding of R8D (diamonds), R4D (squares) and R1D (triangles) by WRN. Error bars indicate SD as derived from three independent experiments.