Biology:Coronaviridae

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Short description: Family of viruses in the order Nidovirales


Coronaviridae
Coronavirus
Viruses-07-01700-g002.jpg
Diagram, electron micrograph, and genome of coronavirus types.
Virus classification e
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Pisuviricota
Class: Pisoniviricetes
Order: Nidovirales
Suborder: Cornidovirineae
Family: Coronaviridae
Subfamilies and genera

Coronaviridae is a family of enveloped, positive-strand RNA viruses which infect amphibians, birds, and mammals. The group includes the subfamilies Letovirinae and Orthocoronavirinae; the members of the latter are known as coronaviruses.

The viral genome is 26–32 kilobases in length. The particles are typically decorated with large (~20 nm), club- or petal-shaped surface projections (the "peplomers" or "spikes"), which in electron micrographs of spherical particles create an image reminiscent of the solar corona.[1][2][3]

Virology

Replication cycle of a coronavirus

The 5' and 3' ends of the genome have a cap and poly(A) tract, respectively. The viral envelope, obtained by budding through membranes of the endoplasmic reticulum (ER) or Golgi apparatus, invariably contains two virus-specified glycoprotein species, known as the spike (S) and membrane (M) proteins. The spike protein makes up the large surface projections (sometimes known as peplomers), while the membrane protein is a triple-spanning transmembrane protein. Toroviruses and a select subset of coronaviruses (in particular the members of subgroup A in the genus Betacoronavirus) possess, in addition to the peplomers composed of S, a second type of surface projections composed of the hemagglutinin-esterase protein. Another important structural protein is the phosphoprotein nucleocapsid protein (N), which is responsible for the helical symmetry of the nucleocapsid that encloses the genomic RNA.[4] The fourth and smallest viral structural protein is known as the envelope protein (E), thought to be involved in viral budding.[5]

Genetic recombination can occur when at least two viral genomes are present in the same infected host cell. RNA recombination appears to be a major driving force in coronavirus evolution. Recombination can determine genetic variability within a CoV species, the capability of a CoV species to jump from one host to another and, infrequently, the emergence of a novel CoV.[6] The exact mechanism of recombination in CoVs is not known, but likely involves template switching during genome replication.[6]

Taxonomy

Taxonomy of family Coronaviridae with species pathogenic to humans

The family Coronaviridae is organized in 2 sub-families, 5 genera, 26 sub-genera, and 46 species.[7] Additional species are pending or tentative.[8]

Coronavirus

Main page: Biology:Coronavirus

Coronavirus is the common name for Coronaviridae and Orthocoronavirinae, also called Coronavirinae.[10][11] Coronaviruses cause diseases in mammals and birds. In humans, the viruses cause respiratory infections. Four human coronaviruses cause typically minor symptoms of a common cold, while three are known to cause more serious illness and can be lethal: SARS-CoV-1, which causes SARS; MERS-CoV, which causes MERS; and SARS-CoV-2, which causes COVID-19.[12] Symptoms vary in other species: in chickens, they cause an upper respiratory disease, while in cows and pigs coronaviruses cause diarrhea. Other than for SARS-CoV-2, there are no vaccines or antiviral drugs to prevent or treat human coronavirus infections. They are enveloped viruses with a positive-sense single-stranded RNA genome and a nucleocapsid of helical symmetry. The genome size of coronaviruses ranges from approximately 26 to 32 kilobases, among the largest for an RNA virus (second only to a 41-kb nidovirus recently discovered in planaria).[13]

Phylogenetic tree of Coronaviridae with host species indicated by color

Orthocoronavirinae taxonomy

References

  1. ↑ Alfarouk, Khalid O.; AlHoufie, Sari T. S.; Ahmed, Samrein B. M.; Shabana, Mona; Ahmed, Ahmed; Alqahtani, Saad S.; Alqahtani, Ali S.; Alqahtani, Ali M. et al. (21 May 2021). "Pathogenesis and Management of COVID-19". Journal of Xenobiotics 11 (2): 77–93. doi:10.3390/jox11020006. PMID 34063739. 
  2. ↑ King, Andrew M. Q.; Adams, Michael J.; Carstens, Eric B. et al., eds. (2012-01-01), "Order - Nidovirales" (in en), Virus Taxonomy (Elsevier): 784–794, doi:10.1016/B978-0-12-384684-6.00066-5, ISBN 978-0-12-384684-6, http://www.sciencedirect.com/science/article/pii/B9780123846846000665, retrieved 2020-06-08 
  3. ↑ Bukhari, Khulud; Mulley, Geraldine; Gulyaeva, Anastasia A.; Zhao, Lanying; Shu, Guocheng; Jiang, Jianping; Neuman, Benjamin W. (2018-11-01). "Description and initial characterization of metatranscriptomic nidovirus-like genomes from the proposed new family Abyssoviridae, and from a sister group to the Coronavirinae, the proposed genus Alphaletovirus" (in en). Virology 524: 160–171. doi:10.1016/j.virol.2018.08.010. ISSN 0042-6822. PMID 30199753. 
  4. ↑ "The coronavirus nucleocapsid is a multifunctional protein". Viruses 6 (8): 2991–3018. August 2014. doi:10.3390/v6082991. PMID 25105276. 
  5. ↑ Schoeman, Dewald; Fielding, Burtram C. (December 2019). "Coronavirus envelope protein: current knowledge". Virology Journal 16 (1): 69. doi:10.1186/s12985-019-1182-0. PMID 31133031. 
  6. ↑ 6.0 6.1 Su S, Wong G, Shi W, Liu J, Lai ACK, Zhou J, Liu W, Bi Y, Gao GF. Epidemiology, Genetic Recombination, and Pathogenesis of Coronaviruses. Trends Microbiol. 2016 Jun;24(6):490-502. DOI: 10.1016/j.tim.2016.03.003. Epub 2016 Mar 21. Review. PMID 27012512
  7. ↑ "Virus Taxonomy: 2019 Release". International Committee on Taxonomy of Viruses. https://ictv.global/taxonomy. 
  8. ↑ "The species Severe acute respiratory syndrome related coronavirus: classifying 2019-nCoV and naming it SARS-CoV-2". Nature Microbiology 5 (4): 536–44. 2020. doi:10.1038/s41564-020-0695-z. PMID 32123347. 
  9. ↑ "Bat Coronaviruses in China". Viruses 11 (3): 210. March 2019. doi:10.3390/v11030210. PMID 30832341. 
  10. ↑ "2017.012-015S" (in en) (xlsx). October 2018. https://ictv.global/ictv/proposals/2017.012_015S.A.v1.Nidovirales.zip. 
  11. ↑ "ICTV Taxonomy history: Orthocoronavirinae" (in en). https://ictv.global/taxonomy/taxondetails?taxnode_id=201851847. 
  12. ↑ "The 2019–2020 Novel Coronavirus (Severe Acute Respiratory Syndrome Coronavirus 2) Pandemic: A Joint American College of Academic International Medicine‑World Academic Council of Emergency Medicine Multidisciplinary COVID‑19 Working Group Consensus Paper". https://www.researchgate.net/publication/340903626. 
  13. ↑ "A planarian nidovirus expands the limits of RNA genome size". PLOS Pathogens 14 (11): e1007314. November 2018. doi:10.1371/journal.ppat.1007314. PMID 30383829. 

External links

Wikidata ☰ Q1134583 entry



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