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

Previous studies reported that GuHCl can inhibit the NT-Pase and helix-unwinding activities of some helicases, such as EV71 2C and human norovirus NS3, as well as the RNA replication of enterovirus and norovirus. Thus, we sought to assess whether the NTPase and helicase-like activities of EBOV VP35 can also be inhibited by this compound. To this end, the ATPase and helix-unwinding assays were conducted in the presence of MBP-VP35 and increasing concentrations of GuHCl. Our data showed that GuHCl could inhibit the ATP hydrolysis ( Figure 8A ) and the RNA helixunwinding by VP35 in a dose-dependent manner ( Figure 8B and C). It is worth to note that the inhibitory effects of GuHCl on the ATPase and helicase-like activities of EBOV VP35 are relatively moderate, similarly with the observed effects on EV71 2C and norovirus NS3 (22, 34) . Altogether, GuHCl is an inhibitor of the NTPase and helicase-like activities of EBOV VP35 in vitro.