Ebola virus VP35 has novel NTPase and helicase-like activities

Shu, Ting; Gan, Tianyu; Bai, Peng; Wang, Xiaotong; Qian, Qi; Zhou, Hui; Cheng, Qi; Qiu, Yang; Yin, Lei; Zhong, Jin; Zhou, Xi

After determining that EBOV VP35 has NTPase activity, we then examined its optimal biochemical reaction conditions, including different salt content, Mg 2+ concentrations, and pH, by using ATP as the substrate. Our data showed that 2 mM Mg 2+ , Mn 2+ , Ca 2+ or Zn 2+ could support the ATPase activity of VP35, and their efficiencies were as follow: Mg 2+ >Zn 2+ >Ca 2+ >Mn 2+ ( Figure 1D ). MBP-VP35 showed the optimal ATPase activity in the presence of 1.5 mM Mg 2+ , while higher concentrations of Mg 2+ had some inhibitory effect on its ATPase activity; and more importantly, the optimal ATPase activity of VP35 requires the presence of Mg 2+ , while VP35 had no ATPase activity in absence of divalent metallic ion ( Figure 1E ), similarly with other NTPases (22, 48) . Additionally, we observed that MBP-VP35 achieved its optimal ATPase activity at pH 8.0 ( Figure 1F) .