Biology:RaTG13

From HandWiki
Short description: Close relative of SARS-CoV-2 discovered in 2013
BatCoV RaTG13
Virus classification e
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Pisuviricota
Class: Pisoniviricetes
Order: Nidovirales
Family: Coronaviridae
Genus: Betacoronavirus
Subgenus: Sarbecovirus
Species:
Severe acute respiratory syndrome–related coronavirus
Strain:
BatCoV RaTG13
Synonyms[1]
  • Bat coronavirus Ra4991

Bat coronavirus RaTG13 is a SARS-like betacoronavirus identified in the droppings of the horseshoe bat Rhinolophus affinis.[2][3] It was discovered in 2013 in bat droppings from a mining cave near the town of Tongguan in Mojiang county in Yunnan, China .[4] In February 2020,[5] it was identified as the closest known relative of SARS-CoV-2, the virus that causes COVID-19, sharing 96.1% nucleotide identity.[6][7] However, in 2022, scientists found three closer matches in bats found 530 km south, in Feuang, Laos, designated as BANAL-52 (96.8% identity), BANAL-103 and BANAL-236.[8][9][10]

History

In spring 2012, three miners cleaning bat feces in an abandoned copper mine near the town of Tongguan in Mojiang Hani Autonomous County developed fatal pneumonia.[11] Out of concerns that the miner's cases could represent a novel disease,[12] serum samples collected from the miners were sent to the Wuhan Institute of Virology and tested by Shi Zhengli and her group for Ebola virus, Nipah virus, and bat SARSr-CoV Rp3. The samples tested negative.[3][13][11]

In order to uncover a possible cause of the infection, different animals (including bats, rats, and musk shrews) were also sampled in and around the mining cave. Between 2012 and 2015, Shi Zhengli and her group isolated 293 different coronaviruses (284 alpha- and 9 beta-coronaviruses) from bat feces samples in the cave. One of the samples collected in 2013 from Rhinolophus affinis (the intermediate horseshoe bat) contained a novel sequence of ribonucleic acids later identified as "RaTG13".[3][13]

In 2020, Shi and her group retested the serum samples from the miners for SARS-CoV-2. The samples tested negative.[3]

In 2020, the strain identified in the sample was renamed from the original Ra4991 (4991st sample collected from Rhinolophus affinis) to "RaTG13", to reflect the originating bat species (Ra from Rhinolophus affinis), geographic location (TG from Tongguan), and year collected (13 from 2013).[14] The name change has been considered innuendo by advocates of the lab leak theory for the COVID-19 pandemic.[14]

Virology

The sequence of RaTG13 was reconstructed from metagenomic sampling (a common practice in environmental virology),[15] and as such, could potentially be an in-silico chimera.[16] RaTG13 has not been confirmed to exist in nature, to have been cultured or isolated in any laboratory,[12] or to be a viable human pathogen.[16] A live virus "RaTG13" has never been detected in any laboratory sample from the WIV or elsewhere.[16]

Based on its sequence, RaTG13 is a positive-strand RNA virus with an outer membrane. Its genome is approximately 29,800 nucleotides. The genome encodes a replicase (ORF1a/1b) and four structural proteins; including a spike protein (S), membrane protein (M), envelope protein (E) and nucleocapsid protein (N); and five viral accessory proteins, including ORF3a (NS3), ORF6 (NS6), ORF7a (NS7a), ORF7b (NS7b) and ORF8 (NS8).[3][17]

RaTG13 bears strong resemblance to the SARS-CoV-2 genome (it shares 96.1% nucleotide similarity), and its identification in animal droppings is a supporting piece of evidence for SARS-CoV-2's natural origin.[7] The main area of divergence between RaTG13 and SARS-CoV-2 is in the receptor-binding domain (RBD) of the spike protein (S), which is the portion that binds to the receptor protein on the surface of the host cell and causes infection. The divergence in this domain indicates that, unlike SARS-CoV-2, the RaTG13 virus might not use angiotensin-converting enzyme 2 (ACE2) as its entry site into the cell.[18] Further, the S protein of RaTG13 virus lacks the furin cleavage motif RRAR↓S.[18]

The binding affinity between RATG13 and hACE2 is lower than that between SARS-CoV-2 RBD and hACE2.[19]

Phylogenetics

Phylogenetic tree

See also

References

  1. ↑ "Taxonomy browser (Bat coronavirus RaTG13)". https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?id=2709072. 
  2. ↑ "Coexistence of multiple coronaviruses in several bat colonies in an abandoned mineshaft". Virologica Sinica 31 (1): 31–40. February 2016. doi:10.1007/s12250-016-3713-9. PMID 26920708. 
  3. ↑ 3.0 3.1 3.2 3.3 3.4 "Addendum: A pneumonia outbreak associated with a new coronavirus of probable bat origin". Nature 588 (7836): E6. December 2020. doi:10.1038/s41586-020-2951-z. PMID 33199918. Bibcode: 2020Natur.588E...6Z. 
  4. ↑ "Addendum: A pneumonia outbreak associated with a new coronavirus of probable bat origin". Nature 588 (7836): E6. December 2020. doi:10.1038/s41586-020-2951-z. PMID 33199918. Bibcode: 2020Natur.588E...6Z. 
  5. ↑ "A pneumonia outbreak associated with a new coronavirus of probable bat origin". Nature 579 (7798): 270–273. March 2020. doi:10.1038/s41586-020-2012-7. PMID 32015507. Bibcode: 2020Natur.579..270Z. 
  6. ↑ "Animal coronaviruses and coronavirus disease 2019: Lesson for One Health approach". Open Veterinary Journal 10 (3): 239–251. October 2020. doi:10.4314/ovj.v10i3.1. PMID 33282694. 
  7. ↑ 7.0 7.1 "SARS-CoV-2, Covid-19, and the debunking of conspiracy theories". Reviews in Medical Virology 31 (6): e2222. November 2021. doi:10.1002/rmv.2222. PMID 33586302. 
  8. ↑ "Bat coronaviruses related to SARS-CoV-2 and infectious for human cells". Nature 604 (7905): 330–336. April 2022. doi:10.1038/s41586-022-04532-4. PMID 35172323. Bibcode: 2022Natur.604..330T. 
  9. ↑ "Closest known relatives of virus behind COVID-19 found in Laos". Nature 597 (7878): 603. September 2021. doi:10.1038/d41586-021-02596-2. PMID 34561634. Bibcode: 2021Natur.597..603M. 
  10. ↑ "Newly Discovered Bat Viruses Give Hints to Covid's Origins". New York Times. 2021-10-14. https://www.nytimes.com/2021/10/14/science/bat-coronaviruses-lab-leak.html. 
  11. ↑ 11.0 11.1 "Novel Henipa-like virus, Mojiang Paramyxovirus, in rats, China, 2012" (in en-us). Emerging Infectious Diseases 20 (6): 1064–1066. June 2014. doi:10.3201/eid2006.131022. PMID 24865545. 
  12. ↑ 12.0 12.1 "The 'Occam's Razor Argument' Has Not Shifted in Favor of a Lab Leak". Snopes. 16 July 2021. https://www.snopes.com/news/2021/07/16/lab-leak-evidence/. 
  13. ↑ 13.0 13.1 "Coexistence of multiple coronaviruses in several bat colonies in an abandoned mineshaft". Virologica Sinica 31 (1): 31–40. February 2016. doi:10.1007/s12250-016-3713-9. PMID 26920708. 
  14. ↑ 14.0 14.1 "The 'Occam's Razor Argument' Has Not Shifted in Favor of a COVID Lab Leak". Snopes. 16 July 2021. https://www.snopes.com/news/2021/07/16/lab-leak-evidence/. 
  15. ↑ "Diversity and evolution of the animal virome". Nature Reviews. Microbiology 20 (6): 321–334. June 2022. doi:10.1038/s41579-021-00665-x. PMID 34983966. 
  16. ↑ 16.0 16.1 16.2 "There is no "origin" to SARS-CoV-2". Environmental Research (Elsevier) 207: 112173. May 2022. doi:10.1016/j.envres.2021.112173. PMID 34626592. Bibcode: 2022ER....207k2173F. 
  17. ↑ "Bat coronavirus RaTG13, complete genome". NCBI. https://www.ncbi.nlm.nih.gov/nuccore/MN996532. 
  18. ↑ 18.0 18.1 "The proximal origin of SARS-CoV-2". Nature Medicine 26 (4): 450–452. April 2020. doi:10.1038/s41591-020-0820-9. PMID 32284615. 
  19. ↑ "Binding and molecular basis of the bat coronavirus RaTG13 virus to ACE2 in humans and other species". Cell 184 (13): 3438–3451.e10. June 2021. doi:10.1016/j.cell.2021.05.031. PMID 34139177. 

Wikidata ☰ Q91561236 entry



Retrieved from "https://handwiki.org/wiki/index.php?title=Biology:RaTG13&oldid=3567090"