''Schizotequatrovirus'' (formerly ''Schizot4virus'') 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 order ''

Caudovirales ''Caudovirales'' is an order of viruses known as the tailed bacteriophages (''cauda'' is Latin for "tail"). Under the Baltimore classification scheme, the ''Caudovirales'' are group I viruses as they have double stranded DNA (dsDNA) genomes, ...

'', in the family ''

Myoviridae ''Myoviridae'' is a family of bacteriophages in the order ''Caudovirales''. Bacteria and archaea serve as natural hosts. There are 625 species in this family, assigned to eight subfamilies and 217 genera. Subdivisions The subfamily ''Tevenvirinae ...

'', in the subfamily ''

Tevenvirinae ''Tevenvirinae'' is a subfamily of viruses in the order ''Caudovirales'', in the family ''Myoviridae''. Bacteria and archaea serve as natural hosts. There are 135 species in this subfamily, most included in 12 genera. Taxonomy The following gene ...

''. Bacteria serve as natural hosts. There are three species in this genus.

Taxonomy

The following list is a map of ''T4virus'' species according to ICTV Master Species List (MSL) 2018a v1:
ICTV MSL 2018a v1] Group: dsDNA * Order: ''

'' :* Family: ''

'' ::* Sub-Family: ''

'' :::* Genus: ''Schizotequatrovirus'' (formerly ''Schizot4virus'', ''Schizot4likevirus'') ::::*'' Vibrio virus KVP40'' ::::*'' Vibrio virus nt1'' (formerly ''Vibrio virus nt-1'') ::::*'' Vibrio virus ValKK3''

Structure

The

virion 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 ...

s of ''Schizotequatrovirus'' 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 a

prolate spheroid A spheroid, also known as an ellipsoid of revolution or rotational ellipsoid, is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters. A spheroid has circu ...

approximately 140 nm in length and 70 nm in width. The tail is around 140 nm long, 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

Genomes are linear. All three species have been fully sequenced. They range between 244k and 248k nucleotides, with 381 to 405 proteins. The complete genomes are available from

National Center for Biotechnology Information The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The ...

NCBI
, along with the complete genome for Vibrio phage VH7D, an unclassified virus strain.

Life cycle

Viral replication is cytoplasmic. 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. DNA-templated transcription is the method of transcription. 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. Bacteria serve as the natural host. Transmission routes are passive diffusion.

History

According to ICTV's 2010–11 report, the genus ''Schizot4likevirus'' was first accepted as a new genus, at the same time as its type species ''Vibrio phage KVP40'', as well as its containing subfamily ''

''. At the same time, '' Vibrio phage nt-1'' was moved into the genus from its previous classification in ''T4-like viruses'' (now ''

T4virus ''Tequatrovirus'' is a genus of viruses in the order ''Caudovirales'', in the family ''Myoviridae'', in the subfamily ''Tevenvirinae''. Gram-negative bacteria serve as the natural host, with transmission achieved through passive diffusion. There ...

''). This proposal is availabl
here
In 2015, the genus was renamed to ''Schizot4virus''. In 2019, with Master Species List 34, the genus was renamed again, now to ''Schizotequatrovirus''

References

External links

ICTV
{{Use dmy dates, date=April 2017 Tevenvirinae Virus genera