Betasphaerolipovirus
Betasphaerolipovirus is a genus of double stranded DNA viruses that infect haloarchaea.[1] Natrinema virus SNJ1 is the type species and currently the only member of the genus.
Natrinema virus SNJ1 | |
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Virus classification | |
(unranked): | Virus |
Realm: | Varidnaviria |
Kingdom: | Helvetiavirae |
Phylum: | Dividoviricota |
Class: | Laserviricetes |
Order: | Halopanivirales |
Family: | Sphaerolipoviridae |
Genus: | Betasphaerolipovirus |
Species: | Natrinema virus SNJ1 |
Morphology
Viruses of this genus have tailless icosahedral virions with an internal lipid membrane located between the protein capsid and the circular double stranded DNA genome.
Replication
The temperate haloarchaeal virus SNJ1 displays lytic and lysogenic life cycles. During the lysogenic cycle, the virus resides in its host, Natrinema sp. J7-1, in the form of an extrachromosomal circular plasmid. Upon mitomycin C induction, large amounts of SNJ1 virions can be produced.[2] SNJ1 genome replicates by the rolling-circle mechanism and is initiated by the virus-encoded RepA protein, which is homologous to the replication-initiation proteins of archaeal plasmids and bacterial transposases of the IS91 family insertion sequences.[3][4] The virus is released by lysis of the infected cells.
References
- Pawlowski A, Rissanen I, Bamford JK, Krupovic M, Jalasvuori M (2014). "Gammasphaerolipovirus, a newly proposed bacteriophage genus, unifies viruses of halophilic archaea and thermophilic bacteria within the novel family Sphaerolipoviridae". Arch Virol. 159 (6): 1541–1554. doi:10.1007/s00705-013-1970-6. PMID 24395078.
- Zhang, Z; Liu, Y; Wang, S; Yang, D; Cheng, Y; Hu, J; Chen, J; Mei, Y; Shen, P; Bamford, DH; Chen, X (2012). "Temperate membrane-containing halophilic archaeal virus SNJ1 has a circular dsDNA genome identical to that of plasmid pHH205". Virology. 434 (2): 233–41. doi:10.1016/j.virol.2012.05.036. PMID 22784791.
- Wang, Yuchen; Chen, Beibei; Cao, Mengzhuo; Sima, Linshan; Prangishvili, David; Chen, Xiangdong; Krupovic, Mart (2018). "Rolling-circle replication initiation protein of haloarchaeal sphaerolipovirus SNJ1 is homologous to bacterial transposases of the IS91 family insertion sequences" (PDF). Journal of General Virology. 99 (3): 416–421. doi:10.1099/jgv.0.001009. PMID 29458508.
- Wang, Y; Sima, L; Lv, J; Huang, S; Liu, Y; Wang, J; Krupovic, M; Chen, X (2016). "Identification, Characterization, and Application of the Replicon Region of the Halophilic Temperate Sphaerolipovirus SNJ1". Journal of Bacteriology. 198 (14): 1952–64. doi:10.1128/JB.00131-16. PMC 4936101. PMID 27137505.