''Cilevirus'' is a genus of
viruses
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are found in almo ...
in the family ''
Kitaviridae''. Plants serve as natural hosts. The genus contains eight species.
Structure
Viruses in ''Cilevirus'' are non-enveloped, with bacilliform geometries. These viruses are about 50 nm wide and 150 nm long. Genomes are linear and segmented, bipartite, around 28.75kb in length.
The genome is bipartite with two segments of 8745 nucleotide (RNA 1) and 4986 nucleotides (RNA 2) in length. The 5' terminals of both segments have a cap structure and have poly adenosine tails in their 3'-terminals. RNA 1 contains two
open reading frame
In molecular biology, reading frames are defined as spans of DNA sequence between the start and stop codons. Usually, this is considered within a studied region of a prokaryotic DNA sequence, where only one of the six possible reading frames ...
s (ORFs) which encode 286 and 29 kilodalton (kDa) proteins. The 286 kDa protein is a polyprotein involved in virus replication and has four conserved domains:
methyltransferase,
protease
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalysis, catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products ...
,
helicase
Helicases are a class of enzymes that are vital to all organisms. Their main function is to unpack an organism's genetic material. Helicases are motor proteins that move directionally along a nucleic double helix, separating the two hybridized ...
and an RNA dependent
RNA polymerase
In molecular biology, RNA polymerase (abbreviated RNAP or RNApol), or more specifically DNA-directed/dependent RNA polymerase (DdRP), is an enzyme that catalyzes the chemical reactions that synthesize RNA from a DNA template.
Using the e ...
. RNA 2 encodes four ORFs which correspond to 15, 61, 32 and 24 kDa proteins. The 32 kDa protein is involved in cell to cell movement of the virus but the functions of the other proteins are unknown.
Life cycle
Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded rna virus transcription is the method of transcription. The virus exits the host cell by tubule-guided viral movement.
Plants serve as the natural host. The virus is transmitted via a vector (mites of the genus brevipalpus). Transmission routes are vector.
Taxonomy
The genus contains the following species, listed by scientific name and followed by the exemplar virus of the species:
* ''Cilevirus australis'',
Ligustrum leprosis virus
* ''Cilevirus colombiaense'',
Citrus leprosis virus C2
* ''Cilevirus leprosis'',
Citrus leprosis virus C
* ''Cilevirus ligustri'',
Ligustrum chlorotic spot virus
* ''Cilevirus oahuense'',
Hibiscus yellow blotch virus
* ''Cilevirus passiflorae'',
Passion fruit green spot virus
* ''Cilevirus pistaciae'',
Pistachio virus Y
* ''Cilevirus solani'',
Solanun violifolium ringspot virus
History
This genus was created in 2006 by Locali-Fabris ''et al'' in 2006.
[Locali-Fabris EC, Freitas-Astúa J, Souza AA, Takita MA, Astúa-Monge G, Antonioli-Luizon R, Rodrigues V, Targon ML, Machado MA (2006) Complete nucleotide sequence, genomic organization and phylogenetic analysis of Citrus leprosis virus cytoplasmic type. J Gen Virol 87(9):2721-2729]
References
External links
Viralzone: CilevirusICTV
{{Taxonbar, from=Q5119936
Positive-sense single-stranded RNA viruses
Riboviria
Virus genera