''Tunavirus'' (synonyms ''T1-like phages'', ''T1-like viruses'', ''Tunalikevirus'') 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'', in the family ''
Drexlerviridae''. Bacteria serve as natural hosts. There are currently 14 species in this genus, including the type species ''
Escherichia virus T1''.
Taxonomy
The following species are recognized:
* ''
Escherichia virus ADB2''
* ''
Escherichia virus BIFF''
* ''
Escherichia virus IME18''
* ''
Escherichia virus JMPW1''
* ''
Escherichia virus JMPW2''
* ''
Escherichia virus SH2''
* ''
Escherichia virus T1''
* ''
Shigella virus 008''
* ''
Shigella virus ISF001''
* ''
Shigella virus PSf2''
* ''
Shigella virus Sfin1''
* ''
Shigella virus SH6''
* ''
Shigella virus Shfl1''
* ''
Shigella virus ISF002''
Structure
Tunaviruses 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 about 60 nm in diameter. The tail is about 151 nm long, 8 nm wide. It's non-contractile, flexible, and has four short, kinked terminal fibers.
Genome
Genomes are circular, around 50kb in length.
[ The type species, ''Escherichia virus T1'', and five other species have been fully sequenced. They range between 45-51k nucleotides, with 45-87 proteins. The complete genomes, as well as two other similar, unclassified genomes are availabl]
here
Life cycle
Viral replication is cytoplasmic. The virus attaches to the host cell's adhesion receptor FhuA using its terminal fibers, and ejects the viral DNA into the host cytoplasm vi
Replication follows the replicative transposition model. 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, and holin/endolysin/spanin proteins. Bacteria serve as the natural host. Transmission routes are passive diffusion.
History
According to ICTV'
1996 report
the genus ''Tunalikevirus'' was first accepted under the name ''T1-like phages'', assigned only to family '' Siphoviridae''. The whole family was moved to order '' Caudovirales'' in 1998, and the genus was renamed to ''T1-like viruses'' in ICTV'
7th Report
in 1999. I
2012
it was renamed again to ''Tunalikevirus''.
References
External links
Viralzone: Tunalikevirus
ICTV
{{Taxonbar, from=Q18813219
Caudovirales
Virus genera