''Lambdavirus'' (synonyms ''Lambda-like viruses'', ''Lambda-like phages'', ''Lambda phage group'', ''Lambda phage'') is a genus of

virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsk ...

es in the order ''

Caudovirales ''Caudovirales'' is an order of viruses known as the tailed bacteriophages (''cauda'' is Latin for "tail"). Under the Baltimore classification scheme, the ''Caudovirales'' are group I viruses as they have double stranded DNA (dsDNA) genomes ...

'', in the family ''

Siphoviridae ''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 structu ...

''. Bacteria serve as natural hosts, with transmission achieved through passive diffusion. There are five species in this genus. The genus also includes several unclassified viruses—including the corynephages β and ω, which infect '' Corynebacterium diphtheriae'' and carry the deadly

diphtheria toxin Diphtheria toxin is an exotoxin secreted by '' Corynebacterium diphtheriae'', the pathogenic bacterium that causes diphtheria. The toxin gene is encoded by a prophageA prophage is a virus that has inserted itself into the genome of the host ...

.NCBI
Corynephage beta
(species)NCBI
Corynephage omega
(species)

Taxonomy

The following species are recognized: * ''

Enterobacteria virus O276 Enterobacteriaceae is a large family of Gram-negative bacteria. It was first proposed by Rahn in 1936, and now includes over 30 genera and more than 100 species. Its classification above the level of family is still a subject of debate, but on ...

'' * ''

Escherichia virus DE3 ''Escherichia'' () is a genus of Gram-negative, non-spore-forming, facultatively anaerobic, rod-shaped bacteria from the family Enterobacteriaceae. In those species which are inhabitants of the gastrointestinal tracts of warm-blooded animals, ''E ...

'' * ''

Escherichia virus HK629 ''Escherichia'' () is a genus of Gram-negative, non-spore-forming, facultatively anaerobic, rod-shaped bacteria from the family Enterobacteriaceae. In those species which are inhabitants of the gastrointestinal tracts of warm-blooded animals, ''E ...

'' * ''

Escherichia virus HK630 ''Escherichia'' () is a genus of Gram-negative, non-spore-forming, facultatively anaerobic, rod-shaped bacteria from the family Enterobacteriaceae. In those species which are inhabitants of the gastrointestinal tracts of warm-blooded animals, ''E ...

'' * '' Escherichia virus Lambda''

Structure

Lambdaviruses are

nonenveloped A viral envelope is the outermost layer of many types of viruses. It protects the genetic material in their life cycle when traveling between host cells. Not all viruses have envelopes. Numerous human pathogenic viruses in circulation are encase ...

, with a head and tail. The head is about 60 nm in diameter, consisting of 72 capsomers (T=7, levo).

Genome

All species have been fully sequenced. They range between 42k and 49k nucleotides, with 56 to 73 proteins.

Life cycle

The virus attaches to the host cell's adhesion receptors using its terminal fiber, and ejects the viral DNA into the host cytoplasm vi
long flexible tail ejection system
Viral replication is cytoplasmic. 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. Once the viral genes have been replicated, the procapsid is assembled and packed. The tail is then assembled and the mature virions are released via lysis, and holin/endolysin/spanin proteins. Bacteria serve as the natural host. Transmission routes are passive diffusion.

History

According to ICTV'
first report
in 1971, the genus ''Lambdalikevirus'' was first accepted under the name ''Lambda phage'', unassigned to order, family, or subfamily. In th
second report
(1975), the genus was renamed to ''Lambda phage group''. Upon its creation in 1984, the genus was assigned to family ''

''. In 1995, ICTV'
sixth report
once again changed the genus' name, this time to ''Lambda-like phages''. The whole family was moved to the newly created order ''

'' in 1998, and the genus was renamed to ''Lambda-like viruses'' in ICTV'
seventh report
in 1999. I
2012
the genus was renamed again, to ''Lambdalikevirus''. The genus was later renamed to ''Lambdavirus''.

References

External links

ICTV
{{Use dmy dates, date=April 2017 Siphoviridae Virus genera