SciTech Daily August 8, 2021
The replication transcription complex (RTC) from the virus SARS-CoV-2 is responsible for recognizing and processing RNA for two principal purposes, propagation into new virus and for ribosomal transcription of viral proteins. The RTC will discontinuously transcribe specific sections of viral RNA to amplify certain proteins over others. A team of researchers in the US (University of Chicago, Lawrence Berkeley National Laboratory, Berkeley, Oak Ridge National Laboratory, University of Auburn) has conducted a systematic structural investigation of three components that make up the RTC: Nsp7, Nsp8, and Nsp12 and solved high-resolution crystal structures of the Nsp7/8 complex, providing insight into the interaction between the proteins. They defined which combination of components forms transient or stable complexes. They used contrast-matching to mask specific complex-forming components to test whether components change conformation upon complexation. They found that individual Nsp7, Nsp8, and Nsp12 structures vary based on whether other proteins in their complex are present. The work has provided greater insight into the RTC assembly, mechanism, and potential avenues for disruption of the complex and its functions…read more. Open Access TECHNICAL ARTICLE
…shows huge quantities of SARS-CoV-2 particles (purple) that have burst out of kidney cells (green), which the virus hijacked for replication… Credit: NIAID Integrated Research Facility