Figure 5

Buc-VBM activates Vasa helicase activity. (A,B) The Y-axis denotes the ATPase activity as a function of the reduction of NADH absorption at 340 nm. The X-axis denotes the incubation time in minutes. The data presented are averaged from three independent experiments. (A) The incubation of 100-µM Buc-VBM with 2.5-mM ATP showed very mild ATPase activity (negative control, blue line). A higher background ATPase activity was observed after the incubation of 5-µM zfVasa with 2.5-mM ATP (black line). Fascinatingly, the ATPase activity was approximately doubled when 100-µM Buc-VBM was added to 5-µM zfVasa and 2.5-mM ATP. (B) The incubation of 100-µM Buc-VBM with 2.5-mM ATP showed mild ATPase activity (pink line). The incubation of 5-µM zfVasa with 2.5-mM ATP displayed relatively higher ATPase activity (green line). The incubation of 5-µM zfVasa with 50-µM ssRNA showed enhanced ATPase activity (red line) compared to 5-µM zfVasa with 100-µM Buc-VBM (blue line). zfVasa ATPase activity was further enhanced in the presence of ssRNA and Buc-VBM (black line).