Notes on Genus: Tremovirus
Type member: Avian encephalomyelitis virus
The genus Tremovirus
(from from an alternative name given to avian encephalomyelitis virus, “epidemic tremor”) is one of the genera in the family Picornaviridae
. Genome organisation is fairly conserved within the family but members of this genus have a 5'-UTR which has no polyC tract, it has neither a leader protein nor an internal capsid (1A) protein and the 2A protein is not a protease.
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.
Monopartite positive sense single-stranded RNA 7.0-7.1 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 a single polyprotein that is subsequently processed into the functional products. The major structural proteins are encoded near the N-terminus.
Type Member Genomic Organization
The genome of about 7,050 nucleotides is translated into a single polyprotein, which is subsequently processed into ten products:
|1B ||26.8 kDa||Coat protein VP2 (surface capsid protein)|
|1C ||27.0 kDa||Coat protein VP3 (surface capsid protein)|
|1D ||31.8 kDa||Coat protein VP1 (surface capsid protein)|
|2A ||18.0 kDa||non-structural protein|
|2B ||10.2 kDa||non-structural protein|
|2C ||25.1 kDa||non-structural protein|
|3A ||18.6 kDa||non-structural protein|
|3B ||2.3 kDa||Genome-linked protein (VPg)|
|3C ||23.9 kDa||protease|
|3D ||55.6 kDa||polymerase|