''Plasmaviridae'' is a family of bacteria-infecting
viruses
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.
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Acholeplasma'' species serve as natural hosts. There is one genus in the family, ''Plasmavirus'', which contains one species: ''Acholeplasma virus L2''.
All viruses known in this family have been isolated from species in the class
Mollicutes
Mollicutes is a class of bacteria distinguished by the absence of a cell wall. The word "Mollicutes" is derived from the Latin ''mollis'' (meaning "soft" or "pliable"), and ''cutis'' (meaning "skin"). Individuals are very small, typically only 0. ...
.
This family is poorly studied and little is known about the diversity and biology of these viruses.
Taxonomy
The family has one genus, ''Plasmavirus'', which has one recognized member: ''Acholeplasma virus L2''.
There are five tentative members of ''Plasmavirus'':
* ''
Mycoplasmatales virus-laidlawii 1'' (L1)
* ''
Mycoplasmatales virus-laidlawii 2'' (L2)
* ''
Mycoplasmatales virus-laidlawii 3'' (L3)
* ''
Mycoplasmatales virus-laidlawii 51'' (L51)
* ''
Mycoplasmatales virus-laidlawii O1'' (O1)
Genome
The genome is condensed, nonsegmented and consists of a single molecule of circular, supercoiled double-stranded DNA, 12 kilobase pairs in length. The genome has a rather high
G-
C content of ~32%.
[Büchen-Osmond, C. (Ed) (2003). 00.053. Plasmaviridae. In: ICTVdB—The Universal Virus Database, version 3. Büchen-Osmond, C. (Ed), ICTVdB Management, The Earth Institute and Department of Epidemiology, Mailman School of Public Health, Columbia University, New York, NY, USA.] The genome has 14 open reading frames,
and encodes at least 15 proteins, of which at least four are structural proteins embedded in the membrane.
Structure
Virions are quasi-spherical, slightly pleomorphic, enveloped and about 80 nm (range 50–125 nm) in diameter.
Life cycle
Viral replication is cytoplasmic. DNA-templated transcription is the method of transcription. The virus exits the host cell by budding. Acholeplasma species serve as the natural host.
Infection
A productive infectious cycle begins before a
lysogenic
Lysogeny, or the lysogenic cycle, is one of two cycles of viral reproduction (the lytic cycle being the other). Lysogeny is characterized by integration of the bacteriophage nucleic acid into the host bacterium's genome or formation of a circu ...
cycle establishes the virus in the infected bacteria. After initial infection of the viral genome the virus may become latent within the host. Lysogeny involves integration into the host chromosome.
References
External links
ICTV Report ''Plasmaviridae''
{{Taxonbar, from=Q956286
Bacteriophages
Virus families