cryo-EM studies of SARS-CoV2 polymerase, nsp12, bound to nsp7 and nsp8 co-factors and inhbited by b12.

The current COVID pandemic illustrates the potential of new emerging viruses and the necessity to explore the antiviral therapeutics. SARS-CoV2 nsp12 polymerase is a crucial drug target as it plays a key role in viral replication machinery. nsp12 performs the RNA dependent RNA polymerase activity, which is stimulated by its interaction with the viral cofactors nsp7 and nsp8. Though additional viral nsp subunits are likely necessary to carry out the full repertoire of replication and transcription activities, the nsp12-nsp7-nsp8 complex so far represents the minimal complex required for nucleotide polymerization. Here, we would like to determine the cryo-EM structure of this three protein complex bound to b12 inhibitor.