Siphoviridae

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Siphoviridae
BacteriophageHK97.jpg
TME picture of an Escherichia virus HK97 virion, Siphoviridae
Virus classification OOjs UI icon edit-ltr.svg
(unranked): Virus
Realm: Duplodnaviria
Kingdom: Heunggongvirae
Phylum: Uroviricota
Class: Caudoviricetes
Order: Caudovirales
Family:Siphoviridae
Genera

see text

Synonyms [1]
  • Styloviridae

Siphoviridae was a family of double-stranded DNA viruses in the order Caudovirales . The family Siphoviridae and order Caudovirales have now been abolished, with the term siphovirus now used to refer to the morphology of viruses in this former family . Bacteria and archaea serve as natural hosts. There was 1,166 species in this former family, assigned to 366 genera and 22 subfamilies. [2] [3] The characteristic structural features of this family are a nonenveloped head and noncontractile tail.

Contents

Structure

Typical structure of a siphovirus Siphoviridae.svg
Typical structure of a siphovirus

Viruses in the former family Siphoviridae are non-enveloped, with icosahedral and head-tail geometries [2] (morphotype B1) or a prolate capsid (morphotype B2), and T=7 symmetry. The diameter is around 60 nm. [2] Members of this family are also characterized by their filamentous, cross-banded, noncontractile tails, usually with short terminal and subterminal fibers. Genomes are double stranded and linear, around 50 kb in length, [2] containing about 70 genes. The guanine/cytosine content is usually around 52%.[ citation needed ]

Life cycle

Viral replication is cytoplasmic. Entry into the host cell is achieved by adsorption into the host cell. 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. The virus exits the host cell by lysis, and holin/endolysin/spanin proteins. [2] Bacteria and archaea serve as the natural host. Transmission routes are passive diffusion. [2]

Taxonomy

Electron micrographs of siphovirus from Cutibacterium acnes (formerly Propionibacterium acnes). Phages were negatively stained and subjected to transmission electron microscopy. The phages have a head of approximately 55 nm in diameter, loaded with genetic material. Their tails have a size of 150 x 10 nm and are flexible and non-contractile. In the lower micrograph, PAD25 is adhering to bacterial cell debris, and two phages have lost their heads. All phages were classified as Siphoviruses based on their morphology. Siphovirus.tiff
Electron micrographs of siphovirus from Cutibacterium acnes (formerly Propionibacterium acnes). Phages were negatively stained and subjected to transmission electron microscopy. The phages have a head of approximately 55 nm in diameter, loaded with genetic material. Their tails have a size of 150 × 10 nm and are flexible and non-contractile. In the lower micrograph, PAD25 is adhering to bacterial cell debris, and two phages have lost their heads. All phages were classified as Siphoviruses based on their morphology.

The following subfamilies are recognized: [3]

The following genera are unassigned to a subfamily: [3]

Please note that genus Inceonvirus is likely misspelled Incheonvirus.

Related Research Articles

<i>Myoviridae</i> Family of viruses

Myoviridae was a family of bacteriophages in the order Caudovirales. The family Myoviridae and order Caudoviraleshave now been abolished, with the term myovirus now used to refer to the morphology of viruses in this former family. Bacteria and archaea serve as natural hosts. There were 625 species in this family, assigned to eight subfamilies and 217 genera.

<i>Podoviridae</i> Family of viruses

Podoviridae was a family of bacteriophage in the order Caudovirales often associated with T-7 like phages. The family and order Caudoviraleshave now been abolished, with the term podovirus now used to refer to the morphology of viruses in this former family. There were 130 species in this family, assigned to 3 subfamilies and 52 genera. This family was characterized by having very short, noncontractile tails. Many former phages in the former family Podoviriade are now classified in the Autographiviridae

<span class="mw-page-title-main">Caudovirales</span> Class of viruses

Caudoviricetes is a class of viruses known as the tailed bacteriophages. Under the Baltimore classification scheme, the Caudoviricetes are group I viruses as they have double stranded DNA (dsDNA) genomes, which can be anywhere from 18,000 base pairs to 500,000 base pairs in length. The virus particles have a distinct shape; each virion has an icosahedral head that contains the viral genome, and is attached to a flexible tail by a connector protein. The order encompasses a wide range of viruses, many containing genes of similar nucleotide sequence and function. However, some tailed bacteriophage genomes can vary quite significantly in nucleotide sequence, even among the same genus. Due to their characteristic structure and possession of potentially homologous genes, it is believed these bacteriophages possess a common origin.

Baltimore classification is a system used to classify viruses based on their manner of messenger RNA (mRNA) synthesis. By organizing viruses based on their manner of mRNA production, it is possible to study viruses that behave similarly as a distinct group. Seven Baltimore groups are described that take into consideration whether the viral genome is made of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA), whether the genome is single- or double-stranded, and whether the sense of a single-stranded RNA genome is positive or negative.

Picovirinae is a subfamily of viruses in the order Caudovirales, in the family Salasmaviridae. Bacteria serve as natural hosts. There are two genera and seven species in this subfamily.

Peduovirinae is a subfamily of viruses in the order Caudovirales, in the family Myoviridae. Bacteria serve as natural hosts. There are 76 species in this subfamily, assigned to 31 genera.

Spounavirinae is a subfamily of viruses in the order Caudovirales, in the family Herelleviridae. Bacteria serve as natural hosts. There are currently five species in this subfamily, divided among 2 genera.

<i>Tevenvirinae</i> Subfamily of viruses

Tevenvirinae is a subfamily of viruses in the order Caudovirales, in the family Myoviridae. Bacteria and archaea serve as natural hosts. There are 135 species in this subfamily, most included in 12 genera.

Muvirus is a genus of viruses in the order Caudovirales, in the family Myoviridae. Bacteria serve as natural hosts, with transmission achieved through passive diffusion. There are two species in this genus.

Myohalovirus is a genus of viruses in the order Caudovirales, in the family Myoviridae. Bacteria and archaea serve as natural hosts. There are three species in this genus.

Salasvirus is a genus of viruses in the order Caudovirales, in the family Salasmaviridae, in the subfamily Picovirinae. Bacteria serve as natural hosts. There are four species in this genus.

Ceduovirus 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.

Fromanvirus is a genus of viruses in the order Caudovirales, in the family Siphoviridae. Bacteria serve as natural hosts, with transmission achieved through passive diffusion. There are 59 species in this genus.

Lambdavirus is a genus of viruses in the order Caudovirales, in the family Siphoviridae. 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.

Ravinvirus is a genus of viruses in the order Caudovirales, in the family Siphoviridae. Bacteria serve as natural hosts, with transmission achieved through passive diffusion. There is only one species in this genus: Escherichia virus N15.

Lomovskayavirus is a genus of viruses in the order Caudovirales, in the family Siphoviridae. Bacteria serve as natural hosts. There are two species in this genus.

Psimunavirus is a genus of viruses in the family Siphoviridae. Bacteria and archaea serve as the natural host, with transmission achieved through passive diffusion. There is only one species in this genus: Psimunavirus psiM2.

Spbetavirus is a genus of viruses in the order Caudovirales, in the family Siphoviridae. Bacteria serve as natural hosts. There is only one species in this genus: Bacillus virus SPbeta.

Tequintavirus is a genus of viruses in the order Caudovirales, in the family Demerecviridae. Bacteria serve as the natural host, with transmission achieved through passive diffusion. There are currently 22 species in this genus, including the type species Escherichia virus T5.

Tunavirus is a genus of viruses in the order Caudovirales, in the family Drexlerviridae. Bacteria serve as natural hosts. There are currently 14 species in this genus, including the type species Escherichia virus T1.

References

  1. ↑ Safferman, R.S.; Cannon, R.E.; Desjardins, P.R.; Gromov, B.V.; Haselkorn, R.; Sherman, L.A.; Shilo, M. (1983). "Classification and Nomenclature of Viruses of Cyanobacteria". Intervirology. 19 (2): 61–66. doi: 10.1159/000149339 . PMID   6408019.
  2. 1 2 3 4 5 6 "Viral Zone". ExPASy. Retrieved 1 July 2015.
  3. 1 2 3 "Virus Taxonomy: 2020 Release". International Committee on Taxonomy of Viruses (ICTV). March 2021. Retrieved 12 May 2021.
  4. ↑ Lood R, Mörgelin M, Holmberg A, Rasmussen M, Collin M (2008). "Inducible Siphoviruses in superficial and deep tissue isolates of Propionibacterium acnes". BMC Microbiol. 8: 139. doi: 10.1186/1471-2180-8-139 . PMC   2533672 . PMID   18702830.

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