| Cowpea mosaic virus | |
|---|---|
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| Structure of the Cowpea mosaic virus based on PDB 2BFU | |
Virus classification | |
| (unranked): | Virus |
| Realm: | Riboviria |
| Kingdom: | Orthornavirae |
| Phylum: | Pisuviricota |
| Class: | Pisoniviricetes |
| Order: | Picornavirales |
| Family: | Secoviridae |
| Genus: | Comovirus |
| Species: | Comovirus vignae |
| Synonyms | |
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Cowpea mosaic virus (CPMV) is a non-envelopedplant virus of thecomovirus group. Infection of a susceptiblecowpealeaf causes a "mosaic"pattern in the leaf, and results in high virus yields (1-2 g/kg). Itsgenome consists of 2 molecules ofpositive-senseRNA (RNA-1 and RNA-2) which are separately encapsidated. Both RNA1 and RNA2 have aVPg (virus genome-linked protein) at the 5'end, andpolyadenylation at the 3' end. Genomic RNA1 and RNA2 are expressed by a polyprotein processing strategy. RNA1 encodeshelicase, VPg,protease andRdRp. RNA2 encodesmovement protein andcoat protein. The virus particles are 28 nm in diameter and contain 60 copies each of a Large (L) and Small (S) coat protein. The structure is well characterised to atomic resolution, and the viral particles are thermostable. The identification of the virus is attributed to Lister and Thresh in 1955,[1] but it is now known as a variant of theSunn-hemp mosaic virus.[2]
CPMV displays a number of features that can be exploited fornanoscale biomaterialfabrication. Itsgenetic, biological and physical properties are well characterised, and it can be isolated readily from plants. There are many stable mutants already prepared that allow specific modification of thecapsid surface. It is possible to attach a number of different chemicals to the virus surface[3][4] and to construct multilayerarrays of suchnanoparticles on solid surfaces. This gives the natural or genetically engineered nanoparticles a range of properties which could be useful in nanotechnological applications such asbiosensors,catalysis and nanoelectronic devices.
One example use of CPMV particles is to amplify signals inmicroarray based sensors. In this application, the virus particles separate thefluorescentdyes used for signaling in order to prevent the formation of non-fluorescentdimers that act asquenchers.[5] Another example is the use of CPMV as a nanoscalebreadboard for molecular electronics.[6]
CPMV particles have also shown potential for in-situ vaccination in cancer immunotherapy[7]