''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 Cell (biology), cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Viruses are ...
es in the family ''
Drexlerviridae''. Bacteria serve as natural hosts. There are 24 species in this genus.
Taxonomy
The genus contains the following species:
* ''
Tunavirus ADB2''
* ''
Tunavirus BIFF''
* ''
Tunavirus chapo''
* ''
Tunavirus CLBP3''
* ''
Tunavirus DELF2''
* ''
Tunavirus IME18''
* ''
Tunavirus ISF001''
* ''
Tunavirus ISF002''
* ''
Tunavirus JMPW1''
* ''
Tunavirus JMPW2''
* ''
Tunavirus leonhardeuler''
* ''
Tunavirus Lg3''
* ''
Tunavirus LHE71''
* ''
Tunavirus PSf2''
* ''
Tunavirus S202''
* ''
Tunavirus SA12KD''
* ''
Tunavirus SA30RD''
* ''
Tunavirus SA32RD''
* ''
Tunavirus Sfin1''
* ''
Tunavirus Sfin3''
* ''
Tunavirus SH2''
* ''
Tunavirus SH6''
* ''
Tunavirus Shfl1''
* ''
Tunavirus T1''
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. A viral envelope protein or E protein is a protein in the env ...
, 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.
[ Bacteriophage 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
''Siphoviridae'' was a family of double-stranded DNA viruses in the order '' Caudovirales''. The family ''Siphoviridae'' and order '' Caudovirales'' have now been abolished, with the term siphovirus now used to refer to the morphology of viruses ...
''. The whole family was moved to order ''Caudovirales
''Caudoviricetes'' is a class of viruses known as tailed viruses and head-tail viruses (''cauda'' is Latin for "tail"). It is the sole representative of its own phylum, ''Uroviricota'' (from ''ouros'' (ουρος), a Greek word for "tailed" + ...
'' 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''. The genus was renamed to ''Tunavirus'' in 2019 and placed in the newly established family '' Drexlerviridae''.
Applications
''Tunavirus T1'' survives drying and remains infectious when airborne. As a result, it is used as a surrogate for airborne human viruses in the testing of air filtering and disinfection methods. It is also able to form aerosol
An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be generated from natural or Human impact on the environment, human causes. The term ''aerosol'' co ...
s.
''Tunavirus T1'' also has a reputation of being able to contaminate a laboratory's entire collection of ''E. coli'' cultures in a matter of hours. George Streisinger
George Streisinger (December 27, 1927 – August 11, 1984) was an American molecular biologist and co-founder of the Institute of Molecular Biology at the University of Oregon. He was the first person to clone a vertebrate, cloning zebrafish in his ...
and Sydney Brenner
Sydney Brenner (13 January 1927 – 5 April 2019) was a South African biologist. In 2002, he shared the Nobel Prize in Physiology or Medicine with H. Robert Horvitz and Sir John E. Sulston. Brenner made significant contributions to wo ...
have humorously suggested intentionally contaminating letters with T1 to deter excessive requests of phage cultures. An alternative explanation is that some of the contamination was by a more loosely defined collection of "T1-like phages" which includes Lula/phi80.
References
External links
Viralzone: Tunalikevirus
ICTV
{{Taxonbar, from=Q18813219
Caudovirales
Virus genera