Fig. 3.

Coronavirinae phylogenetic tree, genome organisation, and nsp3 functional domains. (A) Coronavirinae family tree. Viruses of relevance to this review, and other representative viruses, shown. (B) SARS-CoV genome organisation (not to scale). Structural proteins are in black. The two polyproteins (1a and 1ab) translated by ribosomal frameshifting are shown. Triangles indicate PLpro cleavage sites; the remaining polyprotein cleavage sites are processed by the main 3C-like protease. The 3′ structural and additional accessory proteins differ among coronaviruses. Functional domains encoded by the SARS-CoV (C) and the HCoV-NL63 (D) nsp3 are also shown (not to scale). Domains linked to STING antagonism are highlighted in grey; the precise function of the transmembrane (TM) domain remains unknown. Terms not defined elsewhere; TCoV, turkey coronavirus; IBV, infectious bronchitis virus; Ubl, ubiquitin-like domain; Ac, acidic domain; ADRP, poly(ADP-ribose)-binding/ADP-ribose-1′-phosphatase macrodomain; NAB, nucleic acid-binding domain; G2M, betacoronavirus marker; Y domain, highly conserved coronavirus domain.