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Coronavirus

This page is about the type of many different viruses. For the current outbreak of the SARS-CoV-2, see COVID-19 pandemic.

Coronaviruses are a group of RNA viruses.[5][6] They cause diseases in birds and mammals, including humans. These diseases can be mild, or they can be fatal. In humans and birds, they cause respiratory tract infections. Mild illnesses in humans include some cases of the common cold (which is also caused by other viruses, for example rhinoviruses). More lethal varieties can cause SARS, MERS, and COVID-19.

Orthocoronavirinae
Coronaviruses 004 lores.jpg
Transmission electron micrograph of Avian coronavirus
Illustration of a SARS-CoV-2 virion
Illustration of a SARS-CoV-2 virion[2]     Red: spike proteins (S)     Grey: lipid bilayer envelope     Yellow: envelope proteins (E)     Orange: membrane proteins (M)
Virus classification e
Unrecognized taxon (fix): Coronaviridae
Subfamily: Orthocoronavirinae
Genera[1]
Synonyms[3][4]
  • Coronavirinae

They are enveloped viruses with a positive-sense RNA genome.[7] The genome size of coronaviruses is about 26 to 32 kilobases,[8] which is extraordinarily large for an RNA virus. There are four major groups of coronaviruses, called alpha, beta, gamma, and delta.

The most famous coronavirus is one of the betas, the kind that causes Coronavirus disease 2019 (COVID-19) in humans.

The name "coronavirus" comes from the Latin word corona, meaning "crown" or "halo", and refers to how virions look under an electron microscopy (E.M.).[9] They have a fringe of large, bulbous surface projections looking like a crown. This morphology is created by the viral spike (S) peplomer, which are proteins on the surface of the virus. They decide which cells the virus can infect.

Proteins of coronaviruses are the spike (S), envelope (E), membrane (M), and nucleocapsid (N).

Diseases

Coronaviruses infect the upper respiratory and gastrointestinal tracts of mammals and birds. Six different strains of coronaviruses infect humans. These include:

Coronaviruses are believed to cause many common colds in human adults. The significance and economic impact of coronaviruses is hard to assess. Unlike rhinoviruses (another common cold virus), human coronaviruses are easy to grow in the laboratory.

Structure

Structure of a coronavirus

Coronaviruses are large, spherical particles with unique surface projections.[10] Their size is variable, averageing 80 to 120 nms.[11] The total molecular weight is on average 40,000 kDa. They are enclosed in an envelope studded with projecting protein molecules.[12] These layers protect the virus when it is outside the host cell.[13]

The viral envelope is made up of a lipid bilayer in which the membrane (M), envelope (E), and spike (S) structural proteins are anchored.[14] The ratio of E:S:M in the lipid bilayer is approximately 1:20:300.[15] The E and M protein are the structural proteins that combined with the lipid bilayer to shape the viral envelope and maintain its size. S proteins are needed for interaction with the host cells. But human coronavirus NL63 is peculiar in that its M protein has the binding site for the host cell, and not its S protein.[16] The diameter of the envelope is 85 nm.

History

The earliest reports of a coronavirus infection in animals occurred in the late 1920s, when an acute respiratory infection of domesticated chickens happened in North America.[17] Arthur Schalk and M.C. Hawn in 1931 made the first detailed report which described a new respiratory infection of chickens in North Dakota. It was not realized at the time that three related viruses were involved.[18]

Human coronaviruses were discovered in the 1960's using two different methods.[19][20][21] E.C. Kendall, Malcolm Bynoe, and David Tyrrel, working at the Common Cold Unit of the British Medical Research Council, collected a unique common cold virus B814 in 1961.[22][23][24] The virus could not be cultivated using the techniques which had successfully cultivated rhinoviruses, adenoviruses, and other known common cold viruses. Eventually, this was solved.[25] The new cultivating method was introduced to the lab by Bertil Hoorn.[26] The isolated virus, when put into the noses of volunteers, caused a cold. The virus was inactivated by ether which showed it had a lipid envelope.[22][27][28] The novel virus caused a cold in volunteers and, like B814, was inactivated by ether.[29]

Transmission electron micrograph of organ cultured coronavirus OC43

Scottish virologist June Almeida at St Thomas' Hospital, London, compared the structures of IBV, B814, and 229E in 1967.[30][31] Using transmission electron microscopy,the three viruses were shown to be similar in shape and have club-like spikes.[32] A research group at the National Institute of Health the same year isolated another member of this group of viruses.[33] Like B814, 229E, and IBV, the novel cold virus OC43 had distinctive club-like spikes when observed with the electron microscope.[34][35]

The IBV-like novel cold viruses looked like the mouse hepatitis virus. This new group of viruses were called "coronaviruses" from their crown-like appearance.[36][37] The coronavirus strain B814 was lost. It is not known which present human coronavirus it was.[38] Other human coronaviruses have since been identified, including SARS-CoV in 2003, HCoV NL63 in 2003, HCoV HKU1 in 2004, MERS-CoV in 2013, and SARS-CoV-2 in 2019.[39] There have been a large number of animal coronaviruses identified since the 1960s.

Coronavirus Media

  • Colorized transmission electron micrograph of coronavirus 229E

  • Diagram of the genome and functional domains of the S protein for SARS-CoV and MERS-CoV

  • After binding of the ACE2 receptor, SARS-CoV spike is activated and cleaved at the S1/S2 level.

  • SARS-CoV genome and proteins

  • The life cycle of a coronavirus

  • Replicase-transcriptase complex

  • Transcription of nested mRNAs

  • Nested set of subgenomic mRNAs

Related pages

References

  1. ↑ Virus Taxonomy: 2018b Release (in en). International Committee on Taxonomy of Viruses (ICTV) (March 2019). Retrieved 24 January 2020.
  2. ↑ "The Spiky Blob Seen Around the World". The New York Times. 1 April 2020. https://www.nytimes.com/2020/04/01/health/coronavirus-illustration-cdc.html. Retrieved 6 April 2020. 
  3. ↑ 2017.012-015S (in en). International Committee on Taxonomy of Viruses (ICTV) (October 2018). Retrieved 24 January 2020.
  4. ↑ ICTV Taxonomy history: Orthocoronavirinae' (in en). International Committee on Taxonomy of Viruses (ICTV). Retrieved 24 January 2020.
  5. ↑ de Groot R.J.. Ninth Report of the International Committee on Taxonomy of Viruses (2012)Elsevier, Oxford. p. 806–828. ISBN 978-0-12-384684-6.
  6. ↑ International Committee on Taxonomy of Viruses. ICTV Master Species List 2009 – v10. Retrieved 2020-03-06.
  7. ↑ enveloped = has viral envelopes covering their protective protein capsids; positive sense = the RNA sequence may be directly translated into the desired viral proteins.
  8. ↑ One kilobase = 1000 base pairs
  9. ↑ virion = complete virus particle.
  10. ↑ Ultrastructural characterization of SARS coronavirus. Emerging Infectious Diseases 10 (2) (February 2004). p. 320–6. doi:10.3201/eid1002.030913.
  11. ↑ The molecular biology of coronaviruses. Advances in Virus Research 66 (2006). p. 193–292. ISBN 9780120398690. doi:10.1016/S0065-3527(06)66005-3.
  12. ↑ The chronicles of coronaviruses: the electron microscope, the doughnut, and the spike (in en). Science Vision 20 (2) (2020). p. 78–92. doi:10.33493/scivis.20.02.03.
  13. ↑ A structural analysis of M protein in coronavirus assembly and morphology. Journal of Structural Biology 174 (1) (April 2011). p. 11–22. doi:10.1016/j.jsb.2010.11.021.
  14. ↑ The molecular biology of coronaviruses. Advances in Virus Research 48 (1997). p. 1–100. ISBN 9780120398485. doi:10.1016/S0065-3527(08)60286-9.
  15. ↑ Detection of a coronavirus from turkey poults in Europe genetically related to infectious bronchitis virus of chickens. Birkhäuser Advances in Infectious Diseases BAID. Avian Pathology 30 (4) (August 2001)Birkhäuser. p. 355–68. ISBN 978-3-7643-7339-9. doi:10.1007/3-7643-7339-3_1.
  16. ↑ Membrane Protein of Human Coronavirus NL63 Is Responsible for Interaction with the Adhesion Receptor. Journal of Virology 93 (19) (October 2019). doi:10.1128/JVI.00355-19.
  17. ↑ Coronaviruses, a New Group of Animal RNA Viruses. Avian Diseases 14 (2) (1970). p. 330–336. doi:10.2307/1588476.
  18. ↑ "Il était une fois les coronavirus" (in fr-FR). Réalités Biomédicales. 2020-03-27. https://www.lemonde.fr/blog/realitesbiomedicales/2020/03/27/il-etait-une-fois-les-coronavirus. Retrieved 2020-04-18. 
  19. ↑ History and recent advances in coronavirus discovery. The Pediatric Infectious Disease Journal 24 (11 Suppl) (November 2005). p. S223–7, discussion S226. doi:10.1097/01.inf.0000188166.17324.60.
  20. ↑ The BMJ in 1965. BMJ 369 (April 2020). p. m1547. doi:10.1136/bmj.m1547.
  21. ↑ Monto, Arnold S.. Viral Infections of Humans (in en). Viral infections of humans: epidemiology and control (1984)Springer US. p. 151–165. ISBN 978-1-4684-4727-9. doi:10.1007/978-1-4684-4727-9_7.
  22. ↑ 22.0 22.1 Virus isolations from common colds occurring in a residential school. British Medical Journal 2 (5297) (July 1962). p. 82–6. doi:10.1136/bmj.2.5297.82.
  23. ↑ Richmond, Caroline. David Tyrrell. BMJ : British Medical Journal 330 (7505) (2005-06-18). p. 1451. doi:10.1136/bmj.330.7505.1451.
  24. ↑ Obituary Notices: Malcom Byone (in en). British Medical Journal 2 (5660) (1969-06-28). p. 827–829. doi:10.1136/bmj.2.5660.827.
  25. ↑ Cultivation of a novel type of common-cold virus in organ cultures. British Medical Journal 1 (5448) (June 1965). p. 1467–70. doi:10.1136/bmj.1.5448.1467.
  26. ↑ Tyrrell, David Arthur John. Cold Wars: The Fight Against the Common Cold (in en) (2002)Oxford University Press. p. 93–95. ISBN 978-0-19-263285-2.
  27. ↑ Hagan, William Arthur. Hagan and Bruner's Microbiology and Infectious Diseases of Domestic Animals. (in en) (1988)Cornell University Press. p. 440. ISBN 978-0-8014-1896-9.
  28. ↑ Knapp, Alex. The secret history of The first coronavirus (in en). Forbes. Retrieved 2020-05-06.
  29. ↑ A new virus isolated from the human respiratory tract. Proceedings of the Society for Experimental Biology and Medicine 121 (1) (January 1966). p. 190–3. doi:10.3181/00379727-121-30734.
  30. ↑ The woman who discovered the first coronavirus. Apr 14, 2020. https://www.bbc.com/news/uk-scotland-52278716. Retrieved May 13, 2022. 
  31. ↑ Almeida, Joyce. June Almeida (née Hart) (in en). BMJ 336 (7659) (2008-06-26). p. 1511.1–1511. doi:10.1136/bmj.a434.
  32. ↑ The morphology of three previously uncharacterized human respiratory viruses that grow in organ culture. The Journal of General Virology 1 (2) (April 1967). p. 175–8. doi:10.1099/0022-1317-1-2-175.
  33. ↑ Growth in suckling-mouse brain of "IBV-like" viruses from patients with upper respiratory tract disease. Proceedings of the National Academy of Sciences of the United States of America 58 (6) (December 1967). p. 2268–73. doi:10.1073/pnas.58.6.2268.
  34. ↑ Recovery in tracheal organ cultures of novel viruses from patients with respiratory disease. Proceedings of the National Academy of Sciences of the United States of America 57 (4) (April 1967). p. 933–40. doi:10.1073/pnas.57.4.933.
  35. ↑ Times, Harold M. Schmeck Jr Special To the New York (1967-05-05). "Six newly discovered viruses may explain cold: strains are similar to germ that causes a bronchial infection in chickens believed to be new group" (in en-US). The New York Times. ISSN 0362-4331 . https://www.nytimes.com/1967/05/05/archives/six-newly-discovered-viruses-may-explain-cold-strains-are-similar.html. Retrieved 2020-04-25. 
  36. ↑ Myint, Steven H.. The Coronaviridae (in en). The Viruses (1995)Springer US. p. 389–401. ISBN 978-1-4899-1531-3. doi:10.1007/978-1-4899-1531-3_18.
  37. ↑ Human coronaviruses: insights into environmental resistance and its influence on the development of new antiseptic strategies. Viruses 4 (11) (November 2012). p. 3044–68. doi:10.3390/v4113044.
  38. ↑ Viral Infections of Humans. Emerging Infectious Diseases 20 (8) (August 2014). p. 1319–22. ISBN 978-1-4899-7447-1. doi:10.1007/978-1-4899-7448-8_10.
  39. ↑ A Novel Coronavirus from Patients with Pneumonia in China, 2019. The New England Journal of Medicine 382 (8) (February 2020). p. 727–733. doi:10.1056/NEJMoa2001017.

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