Group Group I (dsDNA) Family Lipothrixviridae | Order Ligamenvirales Rank Genus | |
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Alphalipothrixvirus is a genus of viruses in the order Ligamenvirales, in the family Lipothrixviridae. The thermophilic archaebacterium Thermoproteus tenax serves as natural host. There is currently only one species in this genus: the type species Thermoproteus tenax virus 1.
Contents
Taxonomy
Group: dsDNA
Structure
Viruses in Alphalipothrixvirus are enveloped, with rod-shaped geometries. The diameter is around 38 nm, with a length of 410 nm. Genomes are linear, around 15.9kb in length. The TTV1 virion contains four virus-encoded proteins, TP1-4. The proteins do not display any sequence similarity to structural proteins of other viruses, including lipothrixviruses from other genera. Interestingly, nucleocapsid protein TP1 has apparently evolved from a Cas4 endonuclease, a conserved component of the adaptive CRISPR-Cas immunity, presenting the first described case of exaptation of an enzyme for a virus capsid protein function.
Life Cycle
Viral replication is cytoplasmic. Entry into the host cell is achieved by adsorption into the host cell. DNA-templated transcription is the method of transcription. Thermoproteus archaea serve as the natural host. Transmission routes are passive diffusion.