Mimivirus-dependent virus Zamilon | |
---|---|
![]() | |
Two Zamilon virophages (inset) to scale with their associated giant virus Megavirus [1] | |
Virus classification ![]() | |
(unranked): | Virus |
Realm: | Varidnaviria |
Kingdom: | Bamfordvirae |
Phylum: | Preplasmiviricota |
Class: | Maveriviricetes |
Order: | Priklausovirales |
Family: | Lavidaviridae |
Genus: | Sputnikvirus |
Species: | Mimivirus-dependent virus Zamilon
|
Mimivirus-dependent virus Zamilon, or Zamilon, is a virophage, a group of small DNA viruses that infect protists and require a helper virus to replicate; they are a type of satellite virus.[2] Discovered in 2013 in Tunisia, infecting Acanthamoeba polyphaga amoebae, Zamilon most closely resembles Sputnik, the first virophage to be discovered. The name is Arabic for "the neighbour".[3] Its spherical particle is 50–60 nm in diameter, and contains a circular double-stranded DNA genome of around 17 kb, which is predicted to encode 20 polypeptides. A related strain, Zamilon 2, has been identified in North America.
All known virophages are associated with helpers in the giant DNA virus family Mimiviridae. Zamilon is restricted in its range of helper viruses; it can be supported by viruses from Mimivirus-like Mimiviridae lineages B and C, but not from lineage A. This appears to be a consequence of a rudimentary immune system of the helper virus, termed MIMIVIRE (mimivirus virophage resistance element), akin to the CRISPR-Cas pathway.[4] Unlike the Sputnik virophage, Zamilon does not appear to impair the replication of its helper virus.
Gaia
was invoked but never defined (see the help page).