''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. Since Dmitri Ivanovsky's ...

in the family '' Kitaviridae''. Plants serve as natural hosts. There are two species: '' Citrus leprosis virus C'' and '' Citrus leprosis virus C2''.

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

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, open reading frames (ORFs) 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 readin ...

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 Methyltransferases are a large group of enzymes that all methylate their substrates but can be split into several subclasses based on their structural features. The most common class of methyltransferases is class I, all of which contain a Ross ...

protease A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes (increases reaction rate or "speeds up") proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the ...

helicase Helicases are a class of enzymes thought to be 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 acid phosphodiester backbone, separatin ...

and an RNA dependent RNA polymerase. 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.

Clinical

This virus causes Citrus leprosis disease and is transmitted by

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of the mite genus '' Brevipalpus'' (

Acari Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evid ...

: Tenuipalpidae). This disease is endemic in

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

and has recently spread to

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

. Its spread there represents a threat to citrus industry in the United States.

References

External links

Viralzone: Cilevirus

ICTV
{{Taxonbar, from=Q5119936 Positive-sense single-stranded RNA viruses Riboviria Virus genera