Nepovirus
From Wikipedia, the free encyclopedia
| Nepovirus | ||||||
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Nepoviruses or nematode transmitted polyhedral viruses, are a genus of plant viruses of the family Comoviridae. Nepoviruses, unlike the other two genera (comovirus and fabavirus) in the family Comoviridae, are transmitted by nematodes.
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[edit] Genome
Nepoviruses are classified as type IV viruses under the Baltimore classification system, and consequently contain bipartite, linear, single stranded positive sense RNA genomes. The two genome segments are encapsulated separately into two different icosahedral particles. Each of the genome segments produces a different polypeptide, which under goes a series of steps (i.e. proteolysis, and other post-translational modifications) in order to produce a functional protein.
[edit] RNA1
The first segment (RNA1) is approximately 8,000 nucleotides in length and appears as a single copy in each B type virion. It encodes the proteins that are important in replication and is the first gene to be activated.
[edit] RNA2
The second segment (RNA2) is approximately 4,000–7,000 nucleotides in length and usually appears as a single copy in each M type virion. It encodes the proteins that are important in cell-cell transmission and evasion of cellular defenses.
[edit] Species
There are many members of the genus Nepovirus including the species:
- tobacco ringspot virus
- cherry leaf roll virus
- beet ringspot virus
- raspberry ringspot virus
[edit] References
- Notes on Genus: Nepovirus. Retrieved on 2007-08-06.
