Fig. 2.
Main genome regions of the four CoV genera belong to the subfamily Orthocoronavirinae in the family Coronaviridae. The 5′ untranslated region (UTR), open reading frames (ORFs) 1a/b encoding replicase polyproteins such as papain-like protease (PLpro), chymotrypsin-like protease (3CL), RNA-dependent RNA polymerase (Pol), helicase (Hel), haemagglutinin esterase (HE) and functional nonstructural protein (nsp); and spike (S), envelope (E), membrane (M), nonstructural protein 6/7 (NS6/7), nucleocapsid (N), and 3’ UTR are shown. Transcription-regulatory sequence (TRS). The ribosomal frameshift (RFS) site was indicated. One member of each genus is shown as a representative example. The figure is not drawn to scale