fbpx
Wikipedia

Nidovirales

January 31, 2023

Nidovirales is an order of enveloped, positive-strand RNA viruses which infect vertebrates and invertebrates. Host organisms include mammals, birds, reptiles, amphibians, fish, arthropods, molluscs, and helminths.[1] The order includes the families Coronaviridae, Arteriviridae, Roniviridae, and Mesoniviridae.[2]

Nidovirales
Life cycle of nidoviruses
Virus classification
(unranked): Virus
Realm: Riboviria
Kingdom: Orthornavirae
Phylum: Pisuviricota
Class: Pisoniviricetes
Order: Nidovirales

Member viruses have a viral envelope and a positive-sense, single-stranded RNA genome which is capped and polyadenylated.[3] Nidoviruses are named for the Latin nidus, meaning nest, as all viruses in this order produce a 3' co-terminal nested set of subgenomic mRNAs during infection.[4]

Virology

Structure

 
Comparison of genomes and proteomes of different families of nidoviruses

Nidoviruses have a viral envelope and a positive-sense, single-stranded RNA genome which is capped and polyadenylated.[3] The group expresses structural proteins separately from the nonstructural ones. The structural proteins are encoded at the 3’ region of the genome and are expressed from a set of subgenomic mRNAs.[citation needed]

Member viruses encode one main proteinase and between one and three accessory proteinases which are mainly involved in expressing the replicase gene. These proteinases are also responsible for activating or inactivating specific proteins at the correct time in the virus life cycle, ensuring replication occurs at the right time.[citation needed]

Genome

Nidoviruses can be distinguished from other RNA viruses by a constellation of seven conserved domains—5'-TM2-3CLpro-TM3-RdRp-Zm-HEL1-NendoU-3'—with the first three being encoded in ORF1a and the remaining four in ORF1b. TM2 and TM3 and transmembrane domains; RdRp is the RNA-dependent RNA polymerase; Zm is a Zn-cluster binding domain fused with a helicase (HEL1); 3CLpro is a 3C-like protease; and NendoU is an uridylate-specific endonuclease. The 3CLpro has a catalytic His-Cys dyad, and is related to the SARS coronavirus main proteinase (Mpro).[citation needed]

Most, but not all, nidovirus subgenomic RNAs contain a 5′ leader sequence derived from the 5′ end of the genomic RNA. The frameshift that generates ORF1b frameshift occurs at a UUUAAAC heptanucleotide 'slippery' sequence located upstream of the ORF1a stop codon and a putative RNA pseudoknot structure.[citation needed]

Many proteins have been identified on the genomes of Nidovirales, but their function has not yet been determined. Other enzymes that may be present in the genome include papain-like proteases, ADP-ribose/poly(ADP-ribose)-binding or ADP-ribose 1''-phosphate phosphatase activities and cyclic nucleotide phosphodiesterase.[citation needed]

Phylogenetics

 
Phylogeny and pp1ab domain organization of selected nidoviruses.[5]

The order Nidovirales can be divided into two clades depending on the size of the genome: those with large genomes (26.3–31.7 kilobases) which included the Coronaviridae and Roniviridae (the large nidoviruses) and those with small genomes (the small nidoviruses)—a clade that includes the distantly related Arteriviridae (12.7–15.7 kb).[citation needed]

The large nidoviruses encode both a 2'-O-methyltransferase and a 3'–5' exoribonuclease (ExoN)—the latter being very unusual for an RNA virus. They also encode a superfamily 1 helicase, uridylate-specific endonuclease (an enzyme unique to nidoviruses) and several proteases.[citation needed]

Nidoviruses as a group have the largest RNA genomes of viruses. Group member planarian secretory cell nidovirus (PSCNV) has the largest known nonsegmented RNA genome of 41.1kb.[6] Its host is the planarian flatworm.[7]

Taxonomy

The following suborders and families are recognized (-virineae denotes suborders and -viridae denotes families):[8]

 
Taxonomy tree of the order Nidovirales

See also

References

  1. ^ Ogando, Natacha S.; Ferron, Francois; Decroly, Etienne; Canard, Bruno; Posthuma, Clara C.; Snijder, Eric J. (2019). "The Curious Case of the Nidovirus Exoribonuclease: Its Role in RNA Synthesis and Replication Fidelity". Frontiers in Microbiology. 10: 1813. doi:10.3389/fmicb.2019.01813. ISSN 1664-302X. PMC 6693484. PMID 31440227.
  2. ^ "International Committee on Taxonomy of Viruses (ICTV)". talk.ictvonline.org. Retrieved 2020-06-08.
  3. ^ a b King, Andrew M. Q.; Adams, Michael J.; Carstens, Eric B.; Lefkowitz, Elliot J., eds. (2012-01-01), "Order - Nidovirales", Virus Taxonomy, Elsevier: 784–794, doi:10.1016/B978-0-12-384684-6.00066-5, ISBN 978-0-12-384684-6, S2CID 218627729, retrieved 2020-06-08
  4. ^ Antoine A.F. de Vries, Marian C. Horzinek, Peter J. M. Rottier, Raoul J. de Groot (1997). "The Genome Organization of the Nidovirales: Similarities and Differences between Arteri-, Toro-, and Coronaviruses". Seminars in Virology. 8 (1): 33–47. CiteSeerX 10.1.1.462.1825. doi:10.1006/smvy.1997.0104. PMC 7128191. PMID 32288441. S2CID 85383257.{{cite journal}}: CS1 maint: uses authors parameter (link)
  5. ^ Gulyaeva, Anastasia A.; Gorbalenya, Alexander E. (January 2021). "A nidovirus perspective on SARS-CoV-2". Biochemical and Biophysical Research Communications. 538: 24–34. doi:10.1016/j.bbrc.2020.11.015. PMC 7664520. PMID 33413979.
  6. ^ "Taxonomy browser (Planidovirus 1)". www.ncbi.nlm.nih.gov. Retrieved 2020-06-08.
  7. ^ Saberi, Amir; Gulyaeva, Anastasia A.; Brubacher, John L.; Newmark, Phillip A.; Gorbalenya, Alexander E. (2018-11-01). "A planarian nidovirus expands the limits of RNA genome size". PLOS Pathogens. 14 (11): e1007314. doi:10.1371/journal.ppat.1007314. ISSN 1553-7374. PMC 6211748. PMID 30383829.
  8. ^ "Virus Taxonomy: 2019 Release". talk.ictvonline.org. International Committee on Taxonomy of Viruses. Retrieved 30 April 2020.
  • Ziebuhr, J; Snijder, EJ; Gorbalenya, AE (April 2000). "Virus-encoded proteinases and proteolytic processing in the Nidovirales". The Journal of General Virology. 81 (Pt 4): 853–79. doi:10.1099/0022-1317-81-4-853. PMID 10725411.

External links

  • Nidovirales—ICTVdB—The Universal Virus Database, version 4.
  • Nidovirales at the US National Library of Medicine Medical Subject Headings (MeSH)
  • NIH/MeSH
  • "The Nidoviruses" ISBN 0306466341

January 31, 2023
nidovirales, order, enveloped, positive, strand, viruses, which, infect, vertebrates, invertebrates, host, organisms, include, mammals, birds, reptiles, amphibians, fish, arthropods, molluscs, helminths, order, includes, families, coronaviridae, arteriviridae,. Nidovirales is an order of enveloped positive strand RNA viruses which infect vertebrates and invertebrates Host organisms include mammals birds reptiles amphibians fish arthropods molluscs and helminths 1 The order includes the families Coronaviridae Arteriviridae Roniviridae and Mesoniviridae 2 NidoviralesLife cycle of nidovirusesVirus classification unranked VirusRealm RiboviriaKingdom OrthornaviraePhylum PisuviricotaClass PisoniviricetesOrder NidoviralesMember viruses have a viral envelope and a positive sense single stranded RNA genome which is capped and polyadenylated 3 Nidoviruses are named for the Latin nidus meaning nest as all viruses in this order produce a 3 co terminal nested set of subgenomic mRNAs during infection 4 Contents 1 Virology 1 1 Structure 1 2 Genome 2 Phylogenetics 3 Taxonomy 4 See also 5 References 6 External linksVirology EditStructure Edit Comparison of genomes and proteomes of different families of nidoviruses Nidoviruses have a viral envelope and a positive sense single stranded RNA genome which is capped and polyadenylated 3 The group expresses structural proteins separately from the nonstructural ones The structural proteins are encoded at the 3 region of the genome and are expressed from a set of subgenomic mRNAs citation needed Member viruses encode one main proteinase and between one and three accessory proteinases which are mainly involved in expressing the replicase gene These proteinases are also responsible for activating or inactivating specific proteins at the correct time in the virus life cycle ensuring replication occurs at the right time citation needed Genome Edit Nidoviruses can be distinguished from other RNA viruses by a constellation of seven conserved domains 5 TM2 3CLpro TM3 RdRp Zm HEL1 NendoU 3 with the first three being encoded in ORF1a and the remaining four in ORF1b TM2 and TM3 and transmembrane domains RdRp is the RNA dependent RNA polymerase Zm is a Zn cluster binding domain fused with a helicase HEL1 3CLpro is a 3C like protease and NendoU is an uridylate specific endonuclease The 3CLpro has a catalytic His Cys dyad and is related to the SARS coronavirus main proteinase Mpro citation needed Most but not all nidovirus subgenomic RNAs contain a 5 leader sequence derived from the 5 end of the genomic RNA The frameshift that generates ORF1b frameshift occurs at a UUUAAAC heptanucleotide slippery sequence located upstream of the ORF1a stop codon and a putative RNA pseudoknot structure citation needed Many proteins have been identified on the genomes of Nidovirales but their function has not yet been determined Other enzymes that may be present in the genome include papain like proteases ADP ribose poly ADP ribose binding or ADP ribose 1 phosphate phosphatase activities and cyclic nucleotide phosphodiesterase citation needed Phylogenetics Edit Phylogeny and pp1ab domain organization of selected nidoviruses 5 The order Nidovirales can be divided into two clades depending on the size of the genome those with large genomes 26 3 31 7 kilobases which included the Coronaviridae and Roniviridae the large nidoviruses and those with small genomes the small nidoviruses a clade that includes the distantly related Arteriviridae 12 7 15 7 kb citation needed The large nidoviruses encode both a 2 O methyltransferase and a 3 5 exoribonuclease ExoN the latter being very unusual for an RNA virus They also encode a superfamily 1 helicase uridylate specific endonuclease an enzyme unique to nidoviruses and several proteases citation needed Nidoviruses as a group have the largest RNA genomes of viruses Group member planarian secretory cell nidovirus PSCNV has the largest known nonsegmented RNA genome of 41 1kb 6 Its host is the planarian flatworm 7 Taxonomy EditThe following suborders and families are recognized virineae denotes suborders and viridae denotes families 8 Taxonomy tree of the order Nidovirales Abnidovirineae Abyssoviridae Arnidovirineae Arteriviridae Cremegaviridae Gresnaviridae Olifoviridae Cornidovirineae Coronaviridae Mesnidovirineae Medioniviridae Mesoniviridae Monidovirineae Mononiviridae Nanidovirinae Nanghoshaviridae Nanhypoviridae Ronidovirineae Euroniviridae Roniviridae Tornidovirineae TobaniviridaeSee also EditAnimal viruses CoronavirusesReferences Edit Ogando Natacha S Ferron Francois Decroly Etienne Canard Bruno Posthuma Clara C Snijder Eric J 2019 The Curious Case of the Nidovirus Exoribonuclease Its Role in RNA Synthesis and Replication Fidelity Frontiers in Microbiology 10 1813 doi 10 3389 fmicb 2019 01813 ISSN 1664 302X PMC 6693484 PMID 31440227 International Committee on Taxonomy of Viruses ICTV talk ictvonline org Retrieved 2020 06 08 a b King Andrew M Q Adams Michael J Carstens Eric B Lefkowitz Elliot J eds 2012 01 01 Order Nidovirales Virus Taxonomy Elsevier 784 794 doi 10 1016 B978 0 12 384684 6 00066 5 ISBN 978 0 12 384684 6 S2CID 218627729 retrieved 2020 06 08 Antoine A F de Vries Marian C Horzinek Peter J M Rottier Raoul J de Groot 1997 The Genome Organization of the Nidovirales Similarities and Differences between Arteri Toro and Coronaviruses Seminars in Virology 8 1 33 47 CiteSeerX 10 1 1 462 1825 doi 10 1006 smvy 1997 0104 PMC 7128191 PMID 32288441 S2CID 85383257 a href Template Cite journal html title Template Cite journal cite journal a CS1 maint uses authors parameter link Gulyaeva Anastasia A Gorbalenya Alexander E January 2021 A nidovirus perspective on SARS CoV 2 Biochemical and Biophysical Research Communications 538 24 34 doi 10 1016 j bbrc 2020 11 015 PMC 7664520 PMID 33413979 Taxonomy browser Planidovirus 1 www ncbi nlm nih gov Retrieved 2020 06 08 Saberi Amir Gulyaeva Anastasia A Brubacher John L Newmark Phillip A Gorbalenya Alexander E 2018 11 01 A planarian nidovirus expands the limits of RNA genome size PLOS Pathogens 14 11 e1007314 doi 10 1371 journal ppat 1007314 ISSN 1553 7374 PMC 6211748 PMID 30383829 Virus Taxonomy 2019 Release talk ictvonline org International Committee on Taxonomy of Viruses Retrieved 30 April 2020 Ziebuhr J Snijder EJ Gorbalenya AE April 2000 Virus encoded proteinases and proteolytic processing in the Nidovirales The Journal of General Virology 81 Pt 4 853 79 doi 10 1099 0022 1317 81 4 853 PMID 10725411 External links EditNidovirales ICTVdB The Universal Virus Database version 4 Nidovirales at the US National Library of Medicine Medical Subject Headings MeSH NIH MeSH The Nidoviruses ISBN 0306466341 Retrieved from https en wikipedia org w index php title Nidovirales amp oldid 1136463531, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.