2'-O methylation of RNA cap in SARS-CoV-2 captured by serial crystallography.
Wilamowski, M., Sherrell, D.A., Minasov, G., Kim, Y., Shuvalova, L., Lavens, A., Chard, R., Maltseva, N., Jedrzejczak, R., Rosas-Lemus, M., Saint, N., Foster, I.T., Michalska, K., Satchell, K.J.F., Joachimiak, A.(2021) Proc Natl Acad Sci U S A 118
- PubMed: 33972410 
- DOI: https://doi.org/10.1073/pnas.2100170118
- Primary Citation of Related Structures:  
6XKM, 7JHE, 7JIB, 7JPE - PubMed Abstract: 
The genome of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) coronavirus has a capping modification at the 5'-untranslated region (UTR) to prevent its degradation by host nucleases. These modifications are performed by the Nsp10/14 and Nsp10/16 heterodimers using S-adenosylmethionine as the methyl donor. Nsp10/16 heterodimer is responsible for the methylation at the ribose 2'-O position of the first nucleotide. To investigate the conformational changes of the complex during 2'-O methyltransferase activity, we used a fixed-target serial synchrotron crystallography method at room temperature. We determined crystal structures of Nsp10/16 with substrates and products that revealed the states before and after methylation, occurring within the crystals during the experiments. Here we report the crystal structure of Nsp10/16 in complex with Cap-1 analog ( m7 GpppA m2'-O ). Inhibition of Nsp16 activity may reduce viral proliferation, making this protein an attractive drug target.
Organizational Affiliation: 
Center for Structural Genomics of Infectious Diseases, Consortium for Advanced Science and Engineering, University of Chicago, Chicago, IL 60637.