English: Schematic representations of typical calicivirus genome organizations. (A–D) Genomic full-length RNAs of about 7.5 kb in size contain either two ORFs (in viruses of the genera Lagovirus, Nebovirus, and Sapovirus) or three ORFs (Norovirus and Vesivirus), except for the genomic RNA of Murine norovirus (MNV; genus Norovirus) that may contain an additional ORF (encoding the VF1 protein). (E) All caliciviruses except MNV and vesiviruses have subgenomic RNAs of about 2.1 kb in size with two ORFs that encode the main structural proteins, VP1 and VP2; the subgenomic RNA of MNV includes three ORFs (similar to the corresponding genomic RNA) and the subgenomic RNA of vesiviruses encodes – apart from proteins VP1 and VP2 – a small leader of the capsid protein (LC). Colored boxes represent coding sequences that are flanked by untranslated leader and trailer sequences (shown as lines). Hexagons represent VPg proteins that are covalently bound to the 5′ end of all genomic and subgenomic RNAs; An represents the poly(A) tail at the 3′ end of all genomic and subgenomic RNAs.