''Petuvirus'' 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 1 ...

, in the family ''

Caulimoviridae ''Caulimoviridae'' is a family of viruses infecting plants. There are 94 species in this family, assigned to 11 genera. Viruses belonging to the family ''Caulimoviridae'' are termed double-stranded DNA (dsDNA) reverse-transcribing viruses (or pa ...

'' order ''

Ortervirales ''Ortervirales'' is an order that contains all accepted species of single-stranded RNA viruses that replicate through a DNA intermediate (Group VI) and all accepted species of double-stranded DNA viruses (except ''Hepadnaviridae'') that replicat ...

''. Plants serve as natural hosts. There is only one species in this genus: ''Petunia vein clearing virus''. Diseases associated with this genus include: plants: chlorotic vein clearing, leaf malformation.

Structure

Viruses in Petuvirus are non-enveloped, with icosahedral geometries, and T=7 symmetry. The diameter is around 45-50 nm. Genomes are circular and non-segmented. Its genome is 7200

nucleotides Nucleotides are organic molecules consisting of a nucleoside and a phosphate. They serve as monomeric units of the nucleic acid polymers – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), both of which are essential biomolecules w ...

long and has a

guanine Guanine () ( symbol G or Gua) is one of the four main nucleobases found in the nucleic acids DNA and RNA, the others being adenine, cytosine, and thymine (uracil in RNA). In DNA, guanine is paired with cytosine. The guanine nucleoside is called ...

cytosine Cytosine () ( symbol C or Cyt) is one of the four nucleobases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an am ...

content of 38.2%. There are terminally redundant sequences on the genome which have direct

terminal repeat A long terminal repeat (LTR) is a pair of identical sequences of DNA, several hundred base pairs long, which occur in eukaryotic genomes on either end of a series of genes or pseudogenes that form a retrotransposon or an endogenous retrovirus or ...

s that are reiterated internally in inverted form. The virus codes for 2

ORFs ORFS stands for ''Output RF Spectrum'', where 'RF' stands for Radio Frequency. The acronym ORFS is used in the context of mobile communication systems, e.g., GSM. It stands for the relationship between (a) the frequency offset from the carrier a ...

. Its

capsid A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may ...

shells are multilayered. The capsid is round to elongate with

icosahedral In geometry, an icosahedron ( or ) is a polyhedron with 20 faces. The name comes and . The plural can be either "icosahedra" () or "icosahedrons". There are infinitely many non- similar shapes of icosahedra, some of them being more symmetrica ...

symmetry and the virus is composed of 16% nucleic acid. ''Petuviruses'' have a buoyant

density Density (volumetric mass density or specific mass) is the substance's mass per unit of volume. The symbol most often used for density is ''ρ'' (the lower case Greek letter rho), although the Latin letter ''D'' can also be used. Mathematical ...

in CsCl of 1.31 g cm-3 and there are 1 sedimenting component(s) found in purified preparations. The

sedimentation Sedimentation is the deposition of sediments. It takes place when particles in suspension settle out of the fluid in which they are entrained and come to rest against a barrier. This is due to their motion through the fluid in response to the ...

coefficient is 218–251.5–285 S20w while the thermal inactivation point (TIP) is at 55–57.5–60 °C.DPVWeb.net
/ref>AseanBiotechnology.info
/ref> ''Petuviruses'' (including other members of the ''Caulimovirusus'' such as ''soymoviruses'' and ''Cavemoviruses'') form isometric particles whereas members of ''Badnaviruses'' and ''Tungroviruses'' have bacilliform virus particles.

Life cycle

Viral replication is nuclear/cytoplasmic. Entry into the host cell is achieved by attachment of the viral proteins to host receptors, which mediates endocytosis. Replication follows the dsDNA(RT) replication model. DNA-templated transcription, specifically dsDNA(RT) transcription is the method of transcription. The virus exits the host cell by nuclear pore export, and tubule-guided viral movement. Plants serve as the natural host. Transmission routes are mechanical and grafting.

References

External links

ICTV
{{Taxonbar, from=Q7179429 Caulimoviridae Viral plant pathogens and diseases Virus genera