dcsimg
Image of Enterobacteria phage lambda

Phages With Long Non Contractile Tails

Siphoviridae

Siphoviridae

provided by wikipedia EN

Siphoviridae is a family of double-stranded DNA viruses in the order Caudovirales. Bacteria and archaea serve as natural hosts. There are 1,166 species in this family, assigned to 366 genera and 22 subfamilies.[2][3] The characteristic structural features of this family are a nonenveloped head and noncontractile tail.

Structure

Typical structure of a siphovirus

Viruses in Siphoviridae are non-enveloped, with icosahedral and head-tail geometries[2] (morphotype B1) or a prolate capsid (morphotype B2), and T=7 symmetry. The diameter is around 60 nm.[2] Members of this family are also characterized by their filamentous, cross-banded, noncontractile tails, usually with short terminal and subterminal fibers. Genomes are double stranded and linear, around 50 kb in length,[2] containing about 70 genes. The guanine/cytosine content is usually around 52%.

Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by adsorption into the host cell. Replication follows the replicative transposition model. DNA-templated transcription is the method of transcription. Translation takes place by -1 ribosomal frameshifting, and +1 ribosomal frameshifting. The virus exits the host cell by lysis, and holin/endolysin/spanin proteins.[2] Bacteria and archaea serve as the natural host. Transmission routes are passive diffusion.[2]

Taxonomy

Electron micrographs of siphovirus from Cutibacterium acnes (formerly Propionibacterium acnes). Phages were negatively stained and subjected to transmission electron microscopy. The phages have a head of approximately 55 nm in diameter, loaded with genetic material. Their tails have a size of 150 × 10 nm and are flexible and non-contractile. In the lower micrograph, PAD25 is adhering to bacterial cell debris, and two phages have lost their heads. All phages were classified as Siphoviruses based on their morphology.[4]

The following subfamilies are recognized:[3]

The following genera are unassigned to a subfamily:[3]

Please note that genus Inceonvirus is likely misspelled Incheonvirus.

References

  1. ^ Safferman, R.S.; Cannon, R.E.; Desjardins, P.R.; Gromov, B.V.; Haselkorn, R.; Sherman, L.A.; Shilo, M. (1983). "Classification and Nomenclature of Viruses of Cyanobacteria". Intervirology. 19 (2): 61–66. doi:10.1159/000149339. PMID 6408019.
  2. ^ a b c d e f "Viral Zone". ExPASy. Retrieved 1 July 2015.
  3. ^ a b c "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 12 May 2021.
  4. ^ Lood R, Mörgelin M, Holmberg A, Rasmussen M, Collin M (2008). "Inducible Siphoviruses in superficial and deep tissue isolates of Propionibacterium acnes". BMC Microbiol. 8: 139. doi:10.1186/1471-2180-8-139. PMC 2533672. PMID 18702830.

license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN

Siphoviridae: Brief Summary

provided by wikipedia EN

Siphoviridae is a family of double-stranded DNA viruses in the order Caudovirales. Bacteria and archaea serve as natural hosts. There are 1,166 species in this family, assigned to 366 genera and 22 subfamilies. The characteristic structural features of this family are a nonenveloped head and noncontractile tail.

license
cc-by-sa-3.0
copyright
Wikipedia authors and editors
original
visit source
partner site
wikipedia EN