Alphacoronavirus

Alphacoronavirus
Virus classification
Group:	Group IV ((+)ssRNA)
Order:	Nidovirales
Family:	Coronaviridae
Subfamily:	Coronavirinae
Genus:	Alphacoronavirus
Type species
Alphacoronavirus 1

Alphacoronaviruses are the first of the four genera, alpha-, beta-, gamma-, and delta-coronavirus in the subfamily Coronavirinae of the family Coronaviridae. Coronaviruses are enveloped, positive-sense, single-stranded RNA viruses that include both human and zoonotic species. Within this subfamily, viruses have spherical virions with club-shaped surface projections and a core shell. The name is from the Latin corona, meaning crown, which describes the appearance of the projections seen under electron microscopy that resemble a solar corona. This genus contains what were previously considered phylogroup 1 coronaviruses.^[1]

Both the alpha- and beta-coronavirus lineages descend from the bat gene pool.^[2][3][4]

Virology

The virion is enveloped and spherical measuring 120–160 nm in diameter and a core shell of about 65 nm. Glycoproteins and trimers form large surface projections which create the appearance of solar corona from which it takes its name. The genome is positive-sense, single-stranded RNA with a length of 27 to 29 kilobases and a 3’-polyA tail. Two large, overlapping ORFs at the 5'-end of the genome encode the major non-structural proteins expressed as a fusion protein by ribosomal frameshift. These include regions with protease, helicase and RNA polymerase motifs. There are 7 other genes downstream which encode structural proteins. These are expressed from a 3'-coterminal nested set of subgenomic mRNAs.

Classification

• Order Nidovirales
  • Family Coronaviridae
    • Subfamily Coronavirinae
      • Genus Alphacoronavirus; type species: Alphacoronavirus 1
        • Species: Alphacoronavirus 1, Feline coronavirus , Canine coronavirus , Human coronavirus 229E, Human coronavirus NL63, Miniopterus bat coronavirus 1, Miniopterus bat coronavirus HKU8, Porcine epidemic diarrhea virus, Rhinolophus bat coronavirus HKU2 and Scotophilus bat coronavirus 512. Transmissible gastroenteritis coronavirus

See also

• Coronavirus
• Betacoronavirus
• RNA virus

External links

• http://viralzone.expasy.org/all_by_protein/766.html

References

1. "Alphacoronavirus‡—Springer" (PDF). The Springer Index of Viruses: 371–383. doi:10.1007/978-0-387-95919-1_56. Retrieved 2013-06-10.
2. Woo, P. C.; Wang, M.; Lau, S. K.; Xu, H.; Poon, R. W.; Guo, R.; Wong, B. H.; Gao, K.; Tsoi, H. W.; Huang, Y.; Li, K. S.; Lam, C. S.; Chan, K. H.; Zheng, B. J.; Yuen, K. Y. (2007). "Comparative analysis of twelve genomes of three novel group 2c and group 2d coronaviruses reveals unique group and subgroup features". Journal of Virology. 81 (4): 1574–85. doi:10.1128/JVI.02182-06. PMC 1797546. PMID 17121802.
3. Lau, S. K.; Woo, P. C.; Yip, C. C.; Fan, R. Y.; Huang, Y.; Wang, M.; Guo, R.; Lam, C. S.; Tsang, A. K.; Lai, K. K.; Chan, K. H.; Che, X. Y.; Zheng, B. J.; Yuen, K. Y. (2012). "Isolation and characterization of a novel Betacoronavirus subgroup A coronavirus, rabbit coronavirus HKU14, from domestic rabbits". Journal of Virology. 86 (10): 5481–96. doi:10.1128/JVI.06927-11. PMC 3347282. PMID 22398294.
4. Lau, S. K.; Poon, R. W.; Wong, B. H.; Wang, M.; Huang, Y.; Xu, H.; Guo, R.; Li, K. S.; Gao, K.; Chan, K. H.; Zheng, B. J.; Woo, P. C.; Yuen, K. Y. (2010). "Coexistence of different genotypes in the same bat and serological characterization of Rousettus bat coronavirus HKU9 belonging to a novel Betacoronavirus subgroup". Journal of Virology. 84 (21): 11385–94. doi:10.1128/JVI.01121-10. PMC 2953156. PMID 20702646.