Ceduovirus

Ceduovirus (synonyms c2-like viruses, c2-like phages, C2likevirus) is a genus of viruses in the family Siphoviridae, unassigned to a sub-family. Bacteria serve as the natural host, with transmission achieved through passive diffusion. There are 34 species in this genus.

Taxonomy
The following species are recognized:


 * Lactococcus virus 05802
 * Lactococcus virus 20R03M
 * Lactococcus virus 37203
 * Lactococcus virus 50102
 * Lactococcus virus 50504
 * Lactococcus virus 5171F
 * Lactococcus virus 62402
 * Lactococcus virus 62403
 * Lactococcus virus 62606
 * Lactococcus virus bIBB14
 * Lactococcus virus bIBBA3
 * Lactococcus virus bIBBAm4
 * Lactococcus virus bIBBE1
 * Lactococcus virus bIBBL12
 * Lactococcus virus bIBBp6-4
 * Lactococcus virus bIL67
 * Lactococcus virus blBB94p4
 * Lactococcus virus c2
 * Lactococcus virus CHPC116
 * Lactococcus virus CHPC122
 * Lactococcus virus CHPC966
 * Lactococcus virus CHPC967
 * Lactococcus virus CHPC972
 * Lactococcus virus CHPC1020
 * Lactococcus virus CHPC1170
 * Lactococcus virus CHPC1182
 * Lactococcus virus CHPC1183
 * Lactococcus virus CHPC1242
 * Lactococcus virus D4410
 * Lactococcus virus D4412
 * Lactococcus virus LacS15
 * Lactococcus virus M5938
 * Lactococcus virus PCB1
 * Lactococcus virus PCS1

Structure
Ceduoviruses are nonenveloped, with a head and tail. The prolate head is about 56 nm long and 41 nm wide and has a collar. The tail is cross-banded, is about 86-111 nm long, 8 nm wide, and has short tail fibers. Genomes are linear, around 22kb in length.

Genome
Some species have been fully sequenced. They range between 22k and 23k nucleotides, with 37 to 39 proteins. Complete genomes are available here

Life cycle
Viral replication is cytoplasmic. The virus attaches to the host cell's adhesion receptors using its terminal fibers, and viral exolysin degrades the cell wall enough to eject the viral DNA into the host cytoplasm via long flexible tail ejection system. Replication follows the DNA strand displacement, via replicative transposition model. DNA templated transcription is the method of transcription. Bacteria serve as the natural host. Transmission routes are passive diffusion.

History
According to ICTV's 1996 report, the genus C2likevirus was first accepted under the name c2-like phages, assigned only to family Siphoviridae. The whole family was moved to the newly created order Caudovirales in 1998, and the genus was renamed to c2-like viruses in ICTV's seventh report in 1999. In 2012, the genus was renamed again, this time to C2likevirus. The genus was later renamed to Ceduovirus.