Nepovirus
Encyclopedia
Nepoviruses or nematode transmitted polyhedral viruses, are a genus
of plant virus
es of the family Secoviridae
and subfamily Comovirinae. Nepoviruses, unlike the other two genera (comovirus and fabavirus) in the subfamily Comovirinae, are transmitted by nematode
s.
es under the Baltimore classification system
, and consequently contain bipartite, linear, single stranded positive sense RNA
genome
s. 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.
s in length and appears as a single copy in each B type virion. It encodes the protein
s that are important in replication and is the first gene to be activated.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of plant virus
Plant virus
Plant viruses are viruses that affect plants. Like all other viruses, plant viruses are obligate intracellular parasites that do not have the molecular machinery to replicate without a host. Plant viruses are pathogenic to higher plants...
es of the family Secoviridae
Secoviridae
The Secoviridae are a family of Group IV plant-infecting viruses in the order Picornavirales.They include the following genera:*Cheravirus*Sadwavirus*Sequivirus*Torradovirus*Waikavirus...
and subfamily Comovirinae. Nepoviruses, unlike the other two genera (comovirus and fabavirus) in the subfamily Comovirinae, are transmitted by nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
s.
Genome
Nepoviruses are classified as type IV virusVirus
A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...
es under the Baltimore classification system
Virus classification
Virus classification is the process of naming viruses and placing them into a taxonomic system. Similar to the classification systems used for cellular organisms, virus classification is the subject of ongoing debate and proposals. This is mainly due to the pseudo-living nature of viruses, which...
, and consequently contain bipartite, linear, single stranded positive sense RNA
RNA
Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....
genome
Genome
In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....
s. 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
Proteolysis
Proteolysis is the directed degradation of proteins by cellular enzymes called proteases or by intramolecular digestion.-Purposes:Proteolysis is used by the cell for several purposes...
, and other post-translational modifications) in order to produce a functional protein.
RNA1
The first segment (RNA1) is approximately 8,000 nucleotideNucleotide
Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...
s in length and appears as a single copy in each B type virion. It encodes the protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s that are important in replication and is the first gene to be activated.
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.Species
There are many members of the genus Nepovirus including the species:- Cherry leaf roll virusCherry leaf roll virusCherry leaf roll virus is a plant pathogenic virus of the subfamily Comovirinae, family Secoviridae, order Picornavirales.-External links:***ICTV Virus Taxonomy 2009 *UniProt Taxonomy...
- Grapevine fanleaf virusGrapevine fanleaf virusGrapevine fanleaf virus is a plant pathogenic virus of the family Secoviridae.-External links:**...
- Raspberry ringspot virusRaspberry ringspot virusRaspberry ringspot virus is a plant pathogenic virus of the family Comoviridae.-External links:**...
- Tobacco ringspot virusTobacco ringspot virusTobacco ringspot virus is a plant pathogenic virus in the plant virus family Comoviridae. It is the type species of the Comoviridae Genus Nepovirus. Nepoviruses are be transmitted between plants by nematodes...
External links
- ICTV Virus Taxonomy 2009 http://www.ictvonline.org
- UniProt Taxonomy http://www.uniprot.org/taxonomy/675063