Leviviridae

Leviviridae is a family of positive-strand RNA viruses which infect prokaryotes.[1] Bacteria, including enterobacteria, caulobacter, pseudomonas, and acinetobacter serve as natural hosts for these bacteriophages. They are small viruses with linear, positive-sense, single-stranded RNA genomes that encode four proteins. All phages of this family require bacterial pili to attach to and infect cells.[2] There are currently four species in this family, divided among two genera.[3]

Leviviridae
Leviviridae virion and genomes of
(a) bacteriophage MS2 and
(b) bacteriophage Qβ
Virus classification
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Lenarviricota
Class: Allassoviricetes
Order: Levivirales
Family: Leviviridae
Genera

Structure

Viruses in Leviviridae are non-enveloped, with icosahedral and spherical geometries, and T=3 symmetry. Their virion diameter is around 26 nm.[1]

Genome

Leviviruses have a positive-sense, single-stranded RNA genome. It is linear and non-segmented and around 4kb in length. The genome encodes four proteins, which are the coat, replicase, maturation, and lysis protein.[2]

Life cycle
Leviviridae life cycle

Entry into the host cell is achieved by adsorption into the host cell. Replication follows the positive-strand RNA virus replication model. Positive-strand RNA virus transcription is the method of transcription. Translation takes place by suppression of termination. The virus exits the host cell by bacteria lysis. Enterobacteria, caulobacter, pseudomonas, and acinetobacter serve as the natural host.[1]

Taxonomy

The family has two genera, both of which currently have two known species:[3]

References
  1. "Viral Zone". ExPASy. Retrieved 15 June 2015.
  2. Bollback, JP; Huelsenbeck, JP (February 2001). "Phylogeny, genome evolution, and host specificity of single-stranded RNA bacteriophage (family Leviviridae)". Journal of Molecular Evolution. 52 (2): 117–28. Bibcode:2001JMolE..52..117B. doi:10.1007/s002390010140. PMID 11231891.
  3. International Committee on Taxonomy of Viruses (ICTV). "Virus Taxonomy: 2019 Release". talk.ictvonline.org. Retrieved 2 September 2020.
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