Notes on Genus: Poacevirus
Type member: Triticum mosaic 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 one of the genera in the family Potyviridae. Like the other genera, it is characterised by its flexuous filamentous particles, inclusion bodies in infected plant cells and by having a polyprotein genome strategy. It differs from most of the others in having mite transmission and from the genus Bymovirus in having a monopartite genome. The viruses in this genus are phylogenetically very distant from those of other mite-transmitted members in the genera Rymovirus and Tritimovirus. Their genomes also have a very much longer 5'-UTR (>700 nt). The genus name is derived from Poaceae, the family name of the host plants.
MorphologyVirions filamentous, not enveloped, usually flexuous, 680-750 nm long and 12-15 nm in diameter. Symmetry helical with a pitch of 3.4 nm
Virions composed of 5 % nucleic acid and 95 % protein.
GenomeMonopartite, linear, single stranded, positive sense RNA, 9700-10300 nucleotides long. The 3' terminus has a poly(A) tract and the 5' terminus has a genome-linked protein (VPg).
Genus Genomic OrganizationGenome organisation appears to be uniform throughout this genus and is similar to other members of the family. The genome is translated into a single polyprotein, which is subsequently processed into ten products, with the coat protein at the C-terminus. An additional small ORF (PIPO) is generated by frameshifting within the third (P3) cistron.
Type Member Genomic OrganizationThe genome is translated into a single polyprotein of 353 kDa, from which an estimated ten functional products are produced by proteolytic processing:
|P1 protein|| ||putative protease|| ||45 kDa|
|HC-Pro||putative helper component protease|| ||53 kDa|
|P3 protein||unknown function|| ||33 kDa|
|6K1||unknown function|| ||6 kDa|
|CI||Cylindrical inclusion putative helicase|| ||73 kDa|
|6K2||unknown function|| ||6 kDa|
|VPg||Genome-linked protein|| ||23 kDa|
|NIa-Pro||Nuclear Inclusion putative protease|| ||26 kDa|
|NIb||Nuclear Inclusion putative polymerase|| ||56 kDa|
|CP||coat protein|| ||32 kDa|