Zn2+ Inhibits Coronavirus and Arterivirus RNA Polymerase Activity In Vitro and Zinc Ionophores Block the Replication of These Viruses in Cell Culture

• DOI: 10.1371/journal.ppat.1001176
• Publication Date: 2010-11-04T19:49:17Z
• Authors: Aartjan J. W. te ...; Sjoerd H. E. van ...; Amy C. Sims; Ralph S. Baric; Eric J. Snijder; Martijn J. van He...
• Keywords: Arterivirus; Transcription; Coronavirus

Increasing the intracellular Zn2+ concentration with zinc-ionophores like pyrithione (PT) can efficiently impair replication of a variety RNA viruses, including poliovirus and influenza virus. For some viruses this effect has been attributed to interference viral polyprotein processing. In study we demonstrate that combination PT at low concentrations (2 µM 2 PT) inhibits SARS-coronavirus (SARS-CoV) equine arteritis virus (EAV) in cell culture. The synthesis these two distantly related nidoviruses is catalyzed by an RNA-dependent polymerase (RdRp), which core enzyme their multiprotein transcription complex (RTC). Using activity assay for RTCs isolated from cells infected SARS-CoV or EAV—thus eliminating need transport across plasma membrane—we show RNA-synthesizing both viruses. Enzymatic studies using recombinant RdRps (SARS-CoV nsp12 EAV nsp9) purified E. coli subsequently revealed directly inhibited vitro nidovirus polymerases. More specifically, was found block initiation step synthesis, whereas case RdRp elongation template binding reduced. By chelating MgEDTA, inhibitory divalent cation could be reversed, provides novel experimental tool molecular details transcription.