Family: Picornaviridae

Genus: Grusopivirus

Distinguishing features

The genus is distinguished on the basis of genetic characters. 

Virion

Morphology

No details are available on the morphology of virions. 

Nucleic acid

Genome (S. Yang, Y. Wang, and W. Zhang, unpublished): c. 7,104–7,917 nt (5′-UTR: up to 675 nt; ORF: 6,534–7,137 nt; 3′-UTR: 33–105 nt). The location of the cre has not been identified. 

Genome organization and replication

Genome layout:

grusopivirus A1, A2: VPg+5′-UTR^IRES-[1AB-1C-1D-2A1^npgp/2A2^npgp/2A3^npgp/2A4^H-box/NC-2B-2C/3A-3B-3C-3D]-3′-UTR-poly(A)

grusopivirus B1: VPg+5′-UTR^IRES-[1AB-1C-1D/2A-2B-2C/3A-3B-3C-3D]-3′-UTR-poly(A)

The deduced polyprotein is of 2,178–2,379 amino acids. There is no L protein. The 1AB protein remains uncleaved. The 1C/1D processing site is unclear. Two variant 2A gene regions distinguish the members of Grusopivirus A and Grusopivirus B. Grusopivirus A1 and -A2 have three copies of 2A with NPG↓P motif plus a 2A with H-box/NC motif whereas the 2A protein of grusopivirus 2A has an unknown function. 

Biology

No virus has been isolated. Viral RNA was detected in faecal samples of red-crowned cranes (Grus japonensis). Three genetic types are distinguished by means of phylogenetic analysis (Grusopivirus A: 2 types, Grusopivirus B: 1 type). 

Derivation of names

Grusopivirus: derived from Grus japonensis (host) and picornavirus

Species demarcation criteria

Members of a species of the genus Grusopivirus:

• are less than 30% divergent in polyprotein aa sequence
• are less than 30% divergent in P1 aa sequence
• are less than 20% divergent in 2C+3CD aa sequence

Related, unclassified viruses

Virus names and virus abbreviations are not official ICTV designations. 

* partial genome