| Ortervirales | |
|---|---|
| |
| HI-virión | |
Virus classification
| |
| (unranked): | Virus |
| Realm: | Riboviria |
| Kingdom: | Pararnavirae |
| Phylum: | Artverviricota |
| Class: | Revtraviricetes |
| Order: | Ortervirales |
| Families | |
Ortervirales is an order that contains all accepted species of single-stranded RNA viruses that replicate through a DNA intermediate (Group VI) and all accepted species of double-stranded DNA viruses (except Hepadnaviridae) that replicate through an RNA intermediate (Group VII). [1] [2] The name is derived from the reverse of retro. [3]
All reverse-transcribing viruses possess significant similarities to each other. Their reverse transcriptase proteins share a common origin. Moreover, belpaoviruses, metaviruses, pseudoviruses, and retroviruses have other features in common. Their polymerase proteins are similar in structure and include aspartic protease ( retroviral aspartyl protease) and an integrase belonging to the DDE recombinase superfamily (see Recombination-activating gene [structure]). They also share similar capsid and nucleocapsid proteins/domains. [4] Caulimoviruses also share some features with belpaoviruses, metaviruses, pseudoviruses, and retroviruses such as a homologous aspartate protease. On the other hand, Hepadnaviridae family is part of a sister order of Ortervirales called Blubervirales. [1]
Taxonomy
There are five families in this order:
- Family Belpaoviridae – LTR retrotransposon, Bel/Pao family
- Family Metaviridae – LTR retrotransposon, Ty3/gypsy family
- Family Pseudoviridae – LTR retrotransposon, Ty1/copia family
- Family Retroviridae – Retroviruses, e.g. HIV
- Family Caulimoviridae – dsDNA-RT viruses infecting plants
References
- ^ a b Krupovic, M; Blomberg, J; Coffin, JM; Dasgupta, I; Fan, H; Geering, AD; Gifford, R; Harrach, B; Hull, R; Johnson, W; Kreuze, JF; Lindemann, D; Llorens, C; Lockhart, B; Mayer, J; Muller, E; Olszewski, N; Pappu, HR; Pooggin, M; Richert-Pöggeler, KR; Sabanadzovic, S; Sanfaçon, H; Schoelz, JE; Seal, S; Stavolone, L; Stoye, JP; Teycheney, PY; Tristem, M; Koonin, EV; Kuhn, JH (4 April 2018). "Ortervirales: New virus order unifying five families of reverse-transcribing viruses". Journal of Virology. 92 (12): e00515–18. doi: 10.1128/JVI.00515-18. PMC 5974489. PMID 29618642.
- ^ "Taxonomy". International Committee on Taxonomy of Viruses (ICTV). Retrieved 2018-05-23.
- ^ Jens H. Kuhn, Mart Krupovic, et al.: Creation of new order, Ortervirales, for 5 families of reverse-transcribing viruses, ICTV Proposal (Taxoprop) 2017.013D, DOI:10.1340/RG.2.2.24914.04804
- ^ Krupovic, M; Koonin, EV (2017). "Homologous Capsid Proteins Testify to the Common Ancestry of Retroviruses, Caulimoviruses, Pseudoviruses, and Metaviruses". Journal of Virology. 91 (12): e00210–17. doi: 10.1128/JVI.00210-17. PMC 5446648. PMID 28356531.