Figure 6.

Double-stranded nucleic acid-dependent ATPase assays of Dicer-related helicase (DRH)-1 treated with and without small ubiquitin-like modifier (SUMO) protease. Poly-histidine (His)-SUMO-tagged DRH-1 was digested with and without SUMO protease (a and b, respectively). The ATPase activity of approximately 500 nM of DRH-1 was measured in the absence (open circles on dotted lines) or presence of dsDNA (closed triangles) and dsRNA (closed circles) using a QuantiChrom ATPase/GTPase Assay Kit, as described in the Materials and Methods section. The reactions were performed in duplicate at 37 °C for the indicated periods, and the phosphate amounts generated in the reactions were plotted.