Lipothrixviridae


Lipothrixviridae is a family of viruses in the order Ligamenvirales. Thermophilic archaea in the kingdom Crenarchaeota serve as natural hosts. There are currently eleven species in this family, divided among 4 genera.

Taxonomy

Group: dsDNA

Virology

The viruses are enveloped and filamentous. The capsid varies considerably in length – 410–1950 nanometers – and is 24–38 nm in diameter. The envelope has a monolayer structure and includes di-phytanyl tetraethers lipids.
From either end of the viron are protrusions extending from the core through the envelope. The capsid itself is elongated and exhibits helical symmetry. The core itself is helical.
There are two major capsid proteins. MCP1 and MCP2 form a heterodimer, which wraps around the linear dsDNA genome transforming it into A-form. Interaction between the genome and the MCPs leads to condensation of the genome into the virion superhelix. Genomes are linear, up to 40 kb in length.
GenusStructureSymmetryCapsidGenomic arrangementGenomic segmentation
AlphalipothrixvirusFilamentousHelicalEnvelopedLinearMonopartite
BetalipothrixvirusFilamentousHelicalEnvelopedLinearMonopartite
GammalipothrixvirusFilamentousHelicalEnvelopedLinearMonopartite
DeltalipothrixvirusFilamentousHelicalEnvelopedLinearMonopartite

Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by adsorption to the host cell. Acidianus filamentous virus 1 was found to bind to cellular pili-like appendages. DNA templated transcription is the method of transcription. Archaea serve as the natural host. Transmission routes are passive diffusion.
GenusHost detailsTissue tropismEntry detailsRelease detailsReplication siteAssembly siteTransmission
AlphalipothrixvirusArchea: Saccharolobus-InjectionUnknownCytoplasmCytoplasmPassive diffusion
BetalipothrixvirusArchea: Acidianus, Saccharolobus-InjectionUnknownCytoplasmCytoplasmPassive diffusion
GammalipothrixvirusArchea: Acidianus-InjectionUnknownCytoplasmCytoplasmPassive diffusion
DeltalipothrixvirusArchea: Acidianus-InjectionUnknownCytoplasmCytoplasmPassive diffusion