Notes on Genus: Tospovirus
Type member: Tomato spotted wilt virus
- Members of this Genus
- General Description
- Electron Micrograph
- Genus Genomic Organization
- Genome Map
- Type Member Genomic Organization
- All Known Sequences
- Curated Sequences
General DescriptionThis is the only plant virus genus in the large family Bunyaviridae. Its name is derived from the type member, tomato spotted wilt virus.
MorphologyVirions pleomorphic in shape and size, spheroidal and enveloped, 80-110 nm in diameter. 3 filamentous nucleocapsids per envelope, each 200-3000 nm long (depending on arrangement) and 2-2.5 nm in diameter. Symmetry helical.
Virions composed of 1-2 % nucleic acid, over 50 % protein and 20-30 % lipid.
GenomeLinear, tripartite ssRNA: L (c.8900 nt), M (c.4800 nt) and S (c.2900 nt). Genomic nucleic acid is negative sense (RNA-L), or ambisense (RNA-M and RNA-S). Nucleotide sequences of 3'-termini are complementary to similar regions on the 5' end, thus forming a panhandle.
Genus Genomic OrganizationTranslation of the RNA is believed to produce a polymerase from RNA-L (complementary sense), while RNA-M and RNA-S each produces one product in the virus sense and one in the complementary sense. The coat protein is the complementary sense product of RNA-S.
Type Member Genomic OrganizationTranslation of the RNA is believed to produce the following products:
|ORF ||Segment ||complementary|| Size||Putative function|
|1||RNA-L||complementary ||331.5 kDa ||RNA polymerase|
|2||RNA-M||viral||33.6 kDa ||NSM possibly involved in cell-to-cell movement|
|3||RNA-M||complementary||127.4 kDa ||precursor of glycoproteins G1 and G2|
|4||RNA-S||viral||52.4 kDa ||NSS, unknown function|
|5||RNA-S||complementary||28.8 kDa ||N, nucleoprotein (Coat protein)|