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.
As of March 2020, the ICTV knows the following families and subfamilies, although several genera are still unassigned:
- Order Caudovirales
- Family Autographiviridae
- Subfamily Beijerinckvirinae
- Subfamily Colwellvirinae
- Subfamily Corkvirinae
- Subfamily Krylovirinae
- Subfamily Melnykvirinae
- Subfamily Molineuxvirinae
- Subfamily Okabevirinae
- Subfamily Slopekvirinae
- Subfamily Studiervirinae
- Family Chaseviridae
- Family Demerecviridae
- Drexlerviridae family
- Family Herelleviridae
- Family Myoviridae
- Family Siphoviridae
- further members of the order:
- 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
- NCBI: Bacillus phage Gamma (species)
- ICTV: ICTV Taxonomy history: Enterobacteria phage T4 , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
- SIB: Ackermannviridae , on: ViralZone
- ICTV: Taxonomy history: Paenibacillus virus Lily , EC 51, Berlin, Germany, July 2019; Email ratification March 2020 (MSL # 35)
- NCBI: crAss-like phages
- SIB: crAss-like phages , on: ViralZone
- 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
- NCBI: uncultured crAssphage (species)
- 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, doi : 10.1264 / jsme2.ME16175 . PMID 28321010 . PMC 5478533 (free full text). , pp. 112-117.
- SIB: Double Strand DNA Viruses , on: Viral Zone
- 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
- 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)
- 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)