Structural Basis for the Inhibition of the RNA-Dependent RNA Polymerase from SARS-CoV-2 by Remdesivir

Wanchao Yin; Chunyou Mao; Xiaodong Luan; Dan-Dan Shen; Qingya Shen; Haixia Su; Xiaoxi Wang; Fulai Zhou; Wenfeng Zhao; Minqi Gao; Shenghai Chang; Yuan-Chao Xie; Guanghui Tian; He-Wei Jiang; Sheng-Ce Tao; Jingshan Shen; Yi Jiang; Hualiang Jiang; Yechun Xu; Shuyang Zhang; Yan Zhang; H. Eric Xu

We also purified nsp12 alone and nsp12 by its own showed little activity in binding to a 50-base partial double-stranded template-primer RNA( Figure S1E ), in agreement with previous studies with the SARS-CoV nsp12 (14) . The presence of nsp7 and nsp8 dramatically increased nsp12 activity to bind to the template-primer RNA ( Figure S1E ). The nsp12-nsp7-nsp8 complex also showed RNA polymerization activity on a poly-U template upon addition of adenosine triphosphate (ATP) in a time course-dependent manner ( Figure 1B-1C ). This RNA polymerization activity was effectively inhibited by the addition of the active triphosphate form of Remdesivir (RTP) ( Figure 1D ). Addition of 1 mM RTP in the presence of 10 mM ATP was able to completely inhibit the RdRp polymerization activity. Remdesivir, as a prodrug, at 5 mM concentration, did not have any inhibitory effect on the polymerization activity of the purified enzyme ( Figure S1F ).