Nodaviridae
{{Short description|Family of viruses}}
{{Use dmy dates|date=April 2017}}
{{Virusbox
| image = Journal.ppat.1005203.g001.D.jpg
| image_alt =
| image_caption = Crystal structure of grouper nervous necrosis virus a piscine betanodavirus
| taxon = Nodaviridae
| subdivision_ranks = Genera
| subdivision =
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Nodaviridae is a family of nonenveloped positive-strand RNA viruses.{{cite journal |last1=Sahul Hameed |first1=AS |last2=Ninawe |first2=AS |last3=Nakai |first3=T |last4=Chi |first4=SC |last5=Johnson |first5=KL |last6=ICTV Report |first6=Consortium |title=ICTV Virus Taxonomy Profile: Nodaviridae. |journal=The Journal of General Virology |date=January 2019 |volume=100 |issue=1 |pages=3–4 |doi=10.1099/jgv.0.001170 |pmid=30431412|doi-access=free |s2cid=53435394 }} Vertebrates and invertebrates serve as natural hosts. Diseases associated with this family include: viral encephalopathy and retinopathy in fish. There are two genera in the family.{{cite web |title=ICTV Report Nodaviridae |url=http://www.ictv.global/report/nodaviridae}}{{cite web|title=Viral Zone|url=http://viralzone.expasy.org/all_by_species/47.html|publisher=ExPASy|access-date=15 June 2015}}
History
The name of the family is derived from the Japanese village of Nodamura, Iwate Prefecture where Nodamura virus was first isolated from Culex tritaeniorhynchus mosquitoes.{{cn|date=October 2022}}
Virology
=Structure=
The virus is not enveloped and has an icosahedral capsid (triangulation number = 3) ranging from 29 to 35 nm in diameter. The capsid is constructed of 32 capsomers.
= Genome =
File:Elife-25940-fig1-v2.jpg genome and functional map of replicase protein A.]]
The genome is linear, positive sense, bipartite (composed of two segments – RNA1 and RNA2) single stranded RNA consisting of 4500 nucleotides with a 5’ terminal methylated cap and a non-polyadenylated 3’ terminal.
RNA1, which is ~3.1 kilobases in length, encodes a protein that has multiple functional domains: a mitochondrial targeting domain, a transmembrane domain, an RNA-dependent RNA polymerase (RdRp) domain, a self-interaction domain and an RNA capping domain. In addition, RNA1 encodes a subgenomic RNA3 that encodes protein B2, an RNA silencing inhibitor.
RNA2 encodes protein α, a viral capsid protein precursor, which is auto-cleaved into two mature proteins, a 38 kDa β protein and a 5 kDa γ protein, at a conserved Asn/Ala site during virus assembly.
=Life cycle=
Viral replication is cytoplasmic. Entry into the host cell is achieved by penetration into the host cell. Replication follows the positive stranded RNA virus replication model. Positive stranded RNA virus transcription, using the internal initiation model of subgenomic RNA transcription is the method of transcription. Vertebrates and invertebrates serve as the natural host. Transmission routes are contact and contamination.
Taxonomy
The members of the genus Alphanodavirus were originally isolated from insects while those of the genus Betanodavirus were isolated from fish. A small number of nodoviruses seem to lie outside either of these clades. Flock house virus (FHV) is the best studied of the nodaviruses.
References
{{Reflist}}
External links
- [http://www.ictv.global/report/nodaviridae ICTV Report: Nodaviridae]
- [http://viralzone.expasy.org/all_by_species/47.html Viralzone: Nodaviridae]
{{Baltimore classification}}
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