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Gamma phage.png

Bacillus phage gamma (genus Wbetavirus )

Classification : Viruses
Area : Duplodnaviria
Empire : Heunggongvirae
Phylum : Uroviricota
Class : Caudoviricetes
Order : Caudovirales
Taxonomic characteristics
Genome : dsDNA linear simple
Baltimore : Group 1
Symmetry : icosahedral, tailed
Cover : no
Scientific name

The order Caudovirales (Latin cauda , tail) comprises four families of viruses that use bacteria and archaea as hosts . The members of the caudovirales are therefore classified as bacteriophages . The families are divided mainly on the basis of the morphology of the tail piece on the capsid : Myoviridae (long contractile tail piece), Siphoviridae (long non-contractile tail piece) and Podoviridae (short non-contractile tail piece). However, gene and genome comparisons are becoming increasingly important for taxonomy.


All caudovirales have a single molecule of double-stranded DNA as a genome with a size of 18 to 500  kbp . In addition to the usual nucleotides of the genetic code , the caudovirales also have modified ones, e.g. B. glycosylated bases (with attached additional sugar residues) or 5-hydroxymethylcytosine instead of cytosine . The DNA is located in an icosahedral capsid with a diameter of 45 to 170 nm and usually made up of 72  capsomeres ; the tail piece can be up to 230 nm long.

The genome codes for 27 to over 600  genes , the arrangement of which varies greatly. The genome can be broken through by single-stranded gaps and have covalently bound terminal proteins . In the bacterium, the caudovirales can integrate into the nucleoid ( prophage ) or remain in the cell as a linear or circular plasmid . The number of isolated genomes is relatively high, since the caudovirales are subject to constant genetic exchange between the viral and bacterial genome as well as the horizontal exchange as a plasmid between bacteria. A large number of so-called "mosaic types" are created .


The caudovirales are genetically very old viruses with large population variants and worldwide distribution. It is estimated that approximately virions of Caudovirales in the biosphere are that abutted a distance of 2x light years corresponded. The caudovirales make up the majority of the virioplankton in the seas and waters.


Left to right: Myoviridae , Podoviridae and Siphoviridae

As of March 2020, the ICTV knows the following families and subfamilies, although several genera are still unassigned:

  • Subfamily Beijerinckvirinae
  • Subfamily Colwellvirinae
  • Subfamily Corkvirinae
  • Subfamily Krylovirinae
  • Subfamily Melnykvirinae
  • Subfamily Molineuxvirinae
  • Subfamily Okabevirinae
  • Subfamily Slopekvirinae
  • Subfamily Studiervirinae
  • further members of the order:
  • Genus Lilyvirus with species Paenibacillus virus Lily (formerly Siphoviridae )
  • Group " crAss-like phages " with the species " crAssphage " (possibly belonging to the family Podoviridae )
  • Species " Streptococcus Phage ω1 " (alias " Pneumococcus phage ω1 ", also "ω-1")


  • CM Fauquet, MA Mayo, et al. : Eighth Report of the International Committee on Taxonomy of Viruses , London, San Diego, 2004
  • Bernard N. Fields, David M. Knipe, Peter M. Howley (Eds.): Fields Virology , 4th Edition, Philadelphia 2001

Individual evidence

  1. NCBI: Bacillus phage Gamma (species)
  2. a b c d ICTV: ICTV Taxonomy history: Enterobacteria phage T4 , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
  3. SIB: Ackermannviridae , on: ViralZone
  4. ICTV: Taxonomy history: Paenibacillus virus Lily , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
  5. NCBI: crAss-like phages
  6. SIB: crAss-like phages , on: ViralZone
  7. ^ Eugene V. Koonin, Natalya Yutin: The crAss-like Phage Group: How Metagenomics Reshaped the Human Virome , in: Trends in Microbiology Vol. 28 No. 5, S: 349-359, February 28/1 . May 2020, doi: 10.1016 / j.tim.2020.01.010
  8. a b NCBI: uncultured crAssphage (species)
  9. Ajeng K. Pramono, Hirokazu Kuwahara, Takehiko Itoh, Atsushi Toyoda, Akinori Yamada, Yuichi Hongoh: Discovery and Complete Genome Sequence of a Bacteriophage from an Obligate Intracellular Symbiont of a Cellulolytic Protist in the Termite Gut . In: Microbes and Environments . 32, No. 2, 2017, ISSN  1342-6311 , pp. 112-117. doi : 10.1264 / jsme2.ME16175 . PMID 28321010 . PMC 5478533 (free full text).
  10. SIB: Double Strand DNA Viruses , on: Viral Zone
  11. Jean-Gerard Tiraby, E. Tiraby, M.S. Fox: Pneumococcal bacteriophages , in: Virology Volume 68, December 1975, pp. 566-569, doi: 10.1016 / 0042-6822 (75) 90300-1 , PMID 844
  12. ^ Rubens López López: Streptococcus pneumoniae and its bacteriophages: one long argument . In: Int. Microbiol. . 7, No. 3, 2004, pp. 163-71. PMID 15492930 . PDF (free full text via web archive from August 9, 2017)
  13. Rubens López, Ernesto García: Recent trends on the molecular biology of pneumococcal capsules, lytic enzymes, and bacteriophage , Oxford Academic FEMS Microbiology Reviews. Volume 28, No. 5, November 1, 2004, pp. 554-580, doi: 10.1016 / j.femsre.2004.05.002 (free full text)

Web links

Caudovirales: Families, Genera, and Species (NCBI)