Tunavirus (synonyms T1-like phages, T1-like viruses, Tunalikevirus) is a genus of viruses in the family Drexlerviridae. Bacteria serve as natural hosts. There are 24 species in this genus.[1][2][3]

Taxonomy

The genus contains the following species:[2]

Structure

Tunaviruses are nonenveloped, 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.[1]

Genus Structure Symmetry Capsid Genomic arrangement Genomic segmentation
Tunavirus Head-Tail T=7 Non-enveloped Linear Monopartite

Genome

Genomes are circular, around 50kb in length.[1] 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 available here.[3]

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 via long flexible tail ejection system. 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.[1]

Genus Host details Tissue tropism Entry details Release details Replication site Assembly site Transmission
Tunavirus Bacteria None Injection Lysis Cytoplasm Cytoplasm Passive diffusion

History

According to ICTV's 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's 7th Report in 1999. In 2012, it was renamed again to Tunalikevirus. The genus was renamed to Tunavirus in 2019 and placed in the newly established family Drexlerviridae.[4]

References

  1. ^ a b c d "Viral Zone". ExPASy. Retrieved 1 July 2015.
  2. ^ a b "Virus Taxonomy: 2024 Release". International Committee on Taxonomy of Viruses. Retrieved 28 March 2025.
  3. ^ a b NCBI. "Tunalikevirus Complete Genomes". Retrieved 11 March 2015.
  4. ^ "History of the taxon: Genus: Tunavirus (2024 Release, MSL #40)". International Committee on Taxonomy of Viruses. Retrieved 28 March 2025.
Allikas: http://en.wikipedia.org/wiki/Tunavirus
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