''Hpunavirus'' (synonyms ''Hp1likevirus'' and ''Hpunalikevirus'') is a genus of

virus 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 ...

es in the family '' Myoviridae'', within the subfamily ''

Peduovirinae ''Peduovirinae'' is a subfamily of viruses in the order ''Caudovirales'', in the family ''Myoviridae''. Bacteria serve as natural hosts. There are 76 species in this subfamily, assigned to 31 genera. Taxonomy The following genera are recognized: ...

''. Bacteria serve as the natural host, with transmission achieved through passive diffusion. There are two species in this genus.

Taxonomy

The following two species are assigned to the genus: :*'' Haemophilus virus HP1'' :*'' Haemophilus virus HP2''

Structure

Hpunalikeviruses are

nonenveloped A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes. Numerous human pathogenic viruses in circulation are encase ...

, with a head and tail. The head is approximately 60 nm in diameter and an elongated

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 (T=7), composed of 60 hexamers and 12 pentamers (72 capsomers in total). The tail is around 135 nm long, 18 nm wide, has 6 long terminal fibers, 6 short spikes and a small base plate. The tail is enclosed in a sheath, which loosens and slides around the tail core upon contraction.

Genome

Both species have been fully sequenced. They range between 30k and 34k nucleotides, with 37 to 45 proteins. All complete genomes are available fro
NCBI
ref name=NCBI>

Life cycle

The virus attaches to the host cell using its terminal fibers, and uses viral exolysin to degrade the cell wall enough to eject the viral DNA into the host cytoplasm via contraction of its tail sheath. Once the viral genes have been replicated, the procapsid is assembled and packed. The tail is then assembled and the mature virions are released via lysis.

History

According to ICTV's 2010–11 report, the genus ''Hpunalikevirus'' was first accepted under the name ''Hp1likevirus''. It was a new genus, accepted at the same time as all six of its contained species, as well as its containing subfamily ''

''. The name was changed in the following report (2012). These proposals are availabl
here
an
here
respectively. The name was later renamed to ''Hpunavirus''.

References

{{Use dmy dates, date=April 2017 Myoviridae Virus genera