Myoviruses

Genomes are linear, with double-stranded DNA, around 33-244 kb in length. Genomic codes from 40 to 415 proteins. It has terminally redundant sequences. GC composition is ~ 35%. The genome encodes 200-300 proteins that are transcribed into operons. 5-Hydroxymethylcytosine may be present in the genome (instead of thymidine ).

The tubular tail has helical symmetry and is 16–20 nm in diameter. It consists of a central tube, contractile membrane, collar, base plate, six tail pins and six long fibers. Similar to the tail of the family Tectiviridae , but differs from it in that it is permanent.

Tail contractions require ATP . To compress the shell, the subunits of the shell glide over each other, and the tail is shortened to 10-15 nm in length.

To attach to the host cell, the virus uses its contractile membrane as a syringe, piercing the cell wall with a central tube and injecting the genetic material into the host. The introduced DNA takes over the mechanisms of the host cell for transcription and translation and begins to produce new viruses. Replication follows a replicative transposition model. The virus leaves the host cell by lysis. Bacteria and archaea serve as natural hosts.

According to ICTV, as of March 2019, the family includes 5 subfamilies, as well as 68 genera and 3 species outside of them ^[3] :

• Subfamily Eucampyvirinae (2 genera)
• Subfamily Ounavirinae (4 genera)
• Subfamily Peduovirinae (2 genera)
• Subfamily Tevenvirinae (11 genera and 7 species outside of them)
• Subfamily Vequintavirinae (4 genera)

The Spounavirinae subfamily, which has been included in the myovirus family since 2011, was transferred to the Herelleviridae family of the same order in 2018.

• Phage T4