Birnaviridae
| Birnaviridae | |
|---|---|
| Virus classification | |
| Group: | Group III (dsRNA) |
| Family: | Birnaviridae |
| Genera | |
|
Aquabirnavirus | |
| Birnavirus RNA dependent RNA polymerase (VP1) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Birna_RdRp | ||||||||
| Pfam | PF04197 | ||||||||
| InterPro | IPR007100 | ||||||||
| |||||||||
| Birnavirus VP2 protein | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 crystal structure of infectious bursal disease virus vp2 subviral particle | |||||||||
| Identifiers | |||||||||
| Symbol | Birna_VP2 | ||||||||
| Pfam | PF01766 | ||||||||
| Pfam clan | CL0055 | ||||||||
| InterPro | IPR002662 | ||||||||
| |||||||||
| Birnavirus VP3 protein | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Birna_VP3 | ||||||||
| Pfam | PF01767 | ||||||||
| InterPro | IPR002663 | ||||||||
| |||||||||
| Birnavirus VP4 protein | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Birna_VP4 | ||||||||
| Pfam | PF01768 | ||||||||
| InterPro | IPR002664 | ||||||||
| MEROPS | S50 | ||||||||
| |||||||||
| Birnavirus VP5 protein | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Identifiers | |||||||||
| Symbol | Birna_VP5 | ||||||||
| Pfam | PF03042 | ||||||||
| InterPro | IPR004284 | ||||||||
| |||||||||
The Birnaviridae are a family of viruses, including the following genera:
- Genus Aquabirnavirus; type species: Infectious pancreatic necrosis virus
- Genus Avibirnavirus; type species: Infectious bursal disease virus
- Genus Blosnavirus; type species: Blotched snakehead virus
- Genus Entomobirnavirus; type species: Drosophila X virus
The Birnaviridae are type-III viruses in the Baltimore classification, which means they have a double-stranded RNA genome. The other family of type-III viruses is the Reoviridae.
Birnaviridae proteins
The Birnaviridae genome encodes several proteins:
The Birnaviridae RNA-directed RNA polymerase (VP1), which lacks the highly conserved Gly-Asp-Asp (GDD) sequence, a component of the proposed catalytic site of this enzyme family that exists in the conserved motif VI of the palm domain of other RNA-directed RNA polymerases.[1]
The large RNA segment, segment A, of birnaviruses codes for a polyprotein (N-VP2-VP4-VP3-C) [2] that is processed into the major structural proteins of the virion: VP2, VP3 (a minor structural component of the virus), and into the putative protease VP4.[2] VP4 protein is involved in generating VP2 and VP3.[2] recombinant VP3 is more immunogenic than recombinant VP2.[3]
Infectious pancreatic necrosis virus (IPNV), a birnavirus, is an important pathogen in fish farms. Analyses of viral proteins showed that VP2 is the major structural and immunogenic polypeptide of the virus.[4][5] All neutralizing monoclonal antibodies are specific to VP2 and bind to continuous or discontinuous epitopes. The variable domain of VP2 and the 20 adjacent amino acids of the conserved C-terminal are probably the most important in inducing an immune response for the protection of animals.[4]
Non structural protein VP5 is found in RNA segment A. The function of this small viral protein is unknown. It is believed to be involved in influencing apoptosis, but studies are not completely concurring. The protein can not be found in the virion.
Viruses
The family includes a number of viruses:
Chicken proventricular necrosis virus
References
- ↑ Shwed PS, Dobos P, Cameron LA, Vakharia VN, Duncan R (May 2002). "Birnavirus VP1 proteins form a distinct subgroup of RNA-dependent RNA polymerases lacking a GDD motif". Virology 296 (2): 241â50. doi:10.1006/viro.2001.1334. PMID 12069523.
- ↑ 2.0 2.1 2.2 Jagadish MN, Staton VJ, Hudson PJ, Azad AA (March 1988). "Birnavirus precursor polyprotein is processed in Escherichia coli by its own virus-encoded polypeptide". J. Virol. 62 (3): 1084â7. PMC 253673. PMID 2828658.
- ↑ Moon CH, Do JW, Cha SJ, Bang JD, Park MA, Yoo DJ, Lee JM, Kim HG, Chung DK, Park JW (October 2004). "Comparison of the immunogenicity of recombinant VP2 and VP3 of infectious pancreatic necrosis virus and marine birnavirus". Arch. Virol. 149 (10): 2059â68. PMID 15669113.
- ↑ 4.0 4.1 Heppell J, Tarrab E, Lecomte J, Berthiaume L, Arella M (December 1995). "Strain variability and localization of important epitopes on the major structural protein (VP2) of infectious pancreatic necrosis virus". Virology 214 (1): 40â9. doi:10.1006/viro.1995.9956. PMID 8525637.
- ↑ Nobiron I, Galloux M, Henry C, Torhy C, Boudinot P, Lejal N, Da Costa B, Delmas B (February 2008). "Genome and polypeptides characterization of Tellina virus 1 reveals a fifth genetic cluster in the Birnaviridae family". Virology 371 (2): 350â61. doi:10.1016/j.virol.2007.09.022. PMID 17976679.
External links
This article incorporates text from the public domain Pfam and InterPro IPR002664
This article incorporates text from the public domain Pfam and InterPro IPR002663
This article incorporates text from the public domain Pfam and InterPro IPR004284
This article incorporates text from the public domain Pfam and InterPro IPR002662
This article incorporates text from the public domain Pfam and InterPro IPR007100