Sulfolobus islandicus rod-shaped virus 2

Sulfolobus islandicus rod-shaped virus 2, also referred to as SIRV2, is an archeal virus that whose only known host is the archeaon Sulfolobus islandicus. This virus belongs to the family Rudiviridae.[1] Like other viruses in the family Rudiviridae, it is common in geothermal environments.[1]

Sulfolobus islandicus rod-shaped virus 2
Virus classification
(unranked): Virus
Realm: incertae sedis
Kingdom: incertae sedis
Phylum: incertae sedis
Class: incertae sedis
Order: Ligamenvirales
Family: Rudiviridae
Genus: Rudivirus
Species: Sulfolobus islandicus rod-shaped virus 2

Biology and biochemistry

SIRV2 has a linear double-stranded DNA genome. The viral DNA is replicated by 4 host DNA polymerases: Dpo1 through Dpo4.[1]

The virus has a rod-shaped morphology with a width of 23 nanometers (nm) and a length of 900 nm. Three terminal fibers, 28 nm in length, have been observed on both ends of the virus.[2] The terminal fibers mediate attachment of the virus to type 4 pili abundantly present on the host cell surface.[3][4]

SIRV2 is able to survive additions of 6 molar (M) urea, absolute ethanol, octanol-2, and 0.1% Triton X-100 in neutral pH and 25 degrees Celsius.[2] In vitro testing has shown that SIRV2 is still able to infect at 70-80 degrees Celsius and in a pH 3 solution.[5]

SIRV2gp19 was found to be a single-stranded DNA endonuclease in 2011. This was proven by inducing a mutation in the SIRVgp19 protein Motif II from the amino acid aspartate to alanine which resulted in a loss of nuclease activity. This protein is functional within pH 7-10. Magnesium chloride was found to be a cofactor to this protein in 1971.[6][5] Sodium chloride concentrations above 100 mM inhibit SIRV2gp19.[5]

Structure

A three-dimensional reconstruction of the SIRV2 virion at ~4 angstrom resolution has been obtained by cryo–electron microscopy.[7] The structure revealed a previously unknown form of virion organization, in which the alpha-helical major capsid protein of SIRV2 wraps around the DNA, making it inaccessible to solvent. The viral DNA was found to be entirely in the A-form, which suggested a common mechanism with bacterial spores for protecting DNA in the most adverse environments.

References
  1. Martínez-Alvarez, Laura; Deng, Ling; Peng, Xu (2017-04-19). "Formation of a Viral Replication Focus in Sulfolobus Cells Infected by the Rudivirus Sulfolobus islandicus Rod-Shaped Virus 2". Journal of Virology. 91 (13). doi:10.1128/jvi.00486-17. ISSN 0022-538X. PMC 5469267. PMID 28424282.
  2. Prangishvili, W.; Arnold, D.; Götz, H. P.; Ziese, D.; Holz, U.; Kristjansson, I.; Zillig, J. K. (1999). "A novel virus family, the Rudiviridae: Structure, virus-host interactions and genome variability of the sulfolobus viruses SIRV1 and SIRV2". Genetics. 152 (4): 1387–96. OCLC 678661646. PMC 1460677. PMID 10430569.
  3. Quemin, ER; Lucas, S; Daum, B; Quax, TE; Kühlbrandt, W; Forterre, P; Albers, SV; Prangishvili, D; Krupovic, M (2013). "First insights into the entry process of hyperthermophilic archaeal viruses". Journal of Virology. 87 (24): 13379–85. doi:10.1128/JVI.02742-13. PMC 3838266. PMID 24089554.
  4. Wang, F; Cvirkaite-Krupovic, V; Kreutzberger, MAB; Su, Z; de Oliveira, GAP; Osinski, T; Sherman, N; DiMaio, F; Wall, JS; Prangishvili, D; Krupovic, M; Egelman, EH (2019). "An extensively glycosylated archaeal pilus survives extreme conditions". Nature Microbiology. 4 (8): 1401–1410. doi:10.1038/s41564-019-0458-x. PMC 6656605. PMID 31110358.
  5. Gardner, Andrew F.; Prangishvili, David; Jack, William E. (2011-06-11). "Characterization of Sulfolobus islandicus rod-shaped virus 2 gp19, a single-strand specific endonuclease". Extremophiles. 15 (5): 619–624. doi:10.1007/s00792-011-0385-0. ISSN 1431-0651. PMC 3158340. PMID 21667093.
  6. Kushner, S. R.; Nagaishi, H.; Templin, A.; Clark, A. J. (1971-04-01). "Genetic Recombination in Escherichia coli: The Role of Exonuclease I". Proceedings of the National Academy of Sciences. 68 (4): 824–827. Bibcode:1971PNAS...68..824K. doi:10.1073/pnas.68.4.824. ISSN 0027-8424. PMC 389052. PMID 4927675.
  7. DiMaio, F; Yu, X; Rensen, E; Krupovic, M; Prangishvili, D; Egelman, EH (2015). "Virology. A virus that infects a hyperthermophile encapsidates A-form DNA". Science. 348 (6237): 914–7. doi:10.1126/science.aaa4181. PMC 5512286. PMID 25999507.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.