M plays a predominant role in the intracellular formation of virus particles without requiring S In the presence of tunicamycin coronavirus grows and produces spikeless, noninfectious virions that contain M but devoid of S 4, 5 Comparison of SARS-CoV2 (COVID-19), SARS-CoV, and MERS-CoV The 5′UTR and 3′UTR are involved in inter - and intramolecular interactions and are functionally important for RNA-RNA interactions and for binding of viral and cellular proteins.