Metaviridae
Encyclopedia
Metaviridae are a family of virus
es which exist as retrotransposon
s in a eukaryotic
host’s genome. They are very closely related to retrovirus
es: Metaviridae share many genomic elements with retroviruses, including length, organization, and genes themselves. This includes genes that encode reverse transcriptase
, integrase
, and capsid
proteins. The reverse transcriptase and integrase proteins are needed for the retrotransposon activity of the virus. In some cases, virus-like particles can be formed from capsid proteins.
Some assembled Metaviridae particles can penetrate and infect previously uninfected cells. An example of this is the gypsy, a retroelement found in the Drosophila melanogaster
genome. The ability to infect other cells in determined by the presence of the retroviral env genes which encode coat proteins.
Metaviridae are split into the following genera:
Virus
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 which exist as retrotransposon
Retrotransposon
Retrotransposons are genetic elements that can amplify themselves in a genome and are ubiquitous components of the DNA of many eukaryotic organisms. They are a subclass of transposon. They are particularly abundant in plants, where they are often a principal component of nuclear DNA...
s in a eukaryotic
Eukaryote
A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...
host’s genome. They are very closely related to retrovirus
Retrovirus
A retrovirus is an RNA virus that is duplicated in a host cell using the reverse transcriptase enzyme to produce DNA from its RNA genome. The DNA is then incorporated into the host's genome by an integrase enzyme. The virus thereafter replicates as part of the host cell's DNA...
es: Metaviridae share many genomic elements with retroviruses, including length, organization, and genes themselves. This includes genes that encode reverse transcriptase
Reverse transcriptase
In the fields of molecular biology and biochemistry, a reverse transcriptase, also known as RNA-dependent DNA polymerase, is a DNA polymerase enzyme that transcribes single-stranded RNA into single-stranded DNA. It also helps in the formation of a double helix DNA once the RNA has been reverse...
, integrase
Integrase
Retroviral integrase is an enzyme produced by a retrovirus that enables its genetic material to be integrated into the DNA of the infected cell...
, and capsid
Capsid
A capsid is the protein shell of a virus. It consists of several oligomeric structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The capsid encloses the genetic...
proteins. The reverse transcriptase and integrase proteins are needed for the retrotransposon activity of the virus. In some cases, virus-like particles can be formed from capsid proteins.
Some assembled Metaviridae particles can penetrate and infect previously uninfected cells. An example of this is the gypsy, a retroelement found in the Drosophila melanogaster
Drosophila melanogaster
Drosophila melanogaster is a species of Diptera, or the order of flies, in the family Drosophilidae. The species is known generally as the common fruit fly or vinegar fly. Starting from Charles W...
genome. The ability to infect other cells in determined by the presence of the retroviral env genes which encode coat proteins.
Metaviridae are split into the following genera:
- Genus Metavirus; type species: Saccharomyces cerevisiae Ty3 virus
- Genus Errantivirus; type species: Drosophila melanogaster gypsy virus
- Genus Semotivirus , type species: Ascaris lumbricoides Tas virus