ICTV Virus Taxonomy Profile: Caliciviridae

Abstract

The family Caliciviridae includes viruses with single-stranded, positive-sense RNA genomes of 7.4-8.3 kb. The most clinically important representatives are human noroviruses, which are a leading cause of acute gastroenteritis in humans. Virions are non-enveloped with icosahedral symmetry. Members of seven genera infect mammals (Lagovirus, Norovirus, Nebovirus, Recovirus, Sapovirus, Valovirus and Vesivirus), members of two genera infect birds (Bavovirus and Nacovirus), and members of two genera infect fish (Minovirus and Salovirus). This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the family Caliciviridae, which is available at ictv.global/report/caliciviridae.

Keywords: Caliciviridae; ICTV Report; norovirus; taxonomy.

Fig. 1.

The structure of the calicivirus capsid exemplified by a cryo-image reconstruction of recombinant Norwalk virus-like particles (left). X-ray structure of the Norwalk virus capsid (right) with the shell, protruding 1 and protruding 2 domains shown in blue, red and yellow, respectively. (Courtesy of B. V. Prasad.)

Fig. 2.

Genome organization of human calicivirus MD-145 (AY032605, 7556 nt, genus Norovirus). Protein VPg is covalently linked to the 5′-end of genomic RNA and is depicted by a black circle. Cleavage sites in the ORF1 polyprotein are indicated by arrows; the flanking residues and amino acid coordinates are indicated, although these vary within the family. Pro: protease.