Notes on Genus: Dicipivirus
Type member: Cadicivirus A
The genus Dicipivirus
cornavirus) is one of the genera in the family Picornaviridae
. As the name implies, members of this genus are unusual because their genomes encode two separate polyproteins but phylogenetic analyses place these viruses firmly within the family.
Virions isometric (icosahedral), not enveloped 30 nm in diameter, made of 60 units (protomers) each consisting of one molecule of each of three surface coat proteins and with a fourth internal capsid protein.
Monopartite positive sense single-stranded RNA 8.8 kb in length. There is a genome-linked protein (VPg) at the 5'-terminus and a 3'-polyA tail.
Genus Genomic Organization
The RNA encodes two polyproteins separated by a region of almost 600 nt. Each polyprotein is subsequently processed into the functional products. The major structural proteins are encoded by the 5'-most polyprotein.
Type Member Genomic Organization
The genome of about 8,800 nucleotides is translated into two polyproteins, which are subsequently processed into eleven products:
|Polyprotein 1 (90.9 kDa):
||4.5 kDa||Coat protein VP4 (internal capsid protein)|
||25.4 kDa||Coat protein VP2 (surface capsid protein)|
||27.1 kDa||Coat protein VP3 (surface capsid protein)|
||33.9 kDa||Coat protein VP1 (surface capsid protein)|
|Polyprotein 2 (159.1 kDa):
||15.6 kDa||non-structural protein|
||14.0 kDa||non-structural protein|
||38.7 kDa||non-structural protein|
||10.3 kDa||non-structural protein|
||Genome-linked protein (VPg)|