Nucleocytoviricota

Nucleocytoviricota
Virus classification Edit this classification
(unranked): Virus
Realm: Varidnaviria
Kingdom: Bamfordvirae
Phylum: Nucleocytoviricota
Classes

See text

Synonyms

Megavirales[1]

Nucleocytoviricota is a phylum of viruses.[2] Members of the phylum are also known as the nucleocytoplasmic large DNA viruses (NCLDV), which serves as the basis of the name of the phylum with the suffix -viricota for virus phylum. These viruses are referred to as nucleocytoplasmic because they are often able to replicate in both the host's cell nucleus and cytoplasm.[3]

The phylum is notable for containing the giant viruses.[4][1] There are nine families of NCLDVs that all share certain genomic and structural characteristics; however, it is uncertain whether the similarities of the different families of this group have a common viral ancestor.[5] One feature of this group is a large genome and the presence of many genes involved in DNA repair, DNA replication, transcription, and translation. Typically, viruses with smaller genomes do not contain genes for these processes. Most of the viruses in this family also replicate in both the host's nucleus and cytoplasm, thus the name nucleocytoplasmic.

There are 47 NCLDV core genes currently recognised. These include four key proteins involved in DNA replication and repair: the enzymes DNA polymerase family B, the topoisomerase II A, the FLAP endonuclease and the processing factor proliferating cell nuclear antigen. Other proteins include DNA dependent RNA polymerase II and transcription factor II B.

  1. ^ a b Colson P, De Lamballerie X, Yutin N, Asgari S, Bigot Y, Bideshi DK, Cheng XW, Federici BA, Van Etten JL, Koonin EV, La Scola B, Raoult D (2013). ""Megavirales", a proposed new order for eukaryotic nucleocytoplasmic large DNA viruses". Archives of Virology. 158 (12): 2517–21. doi:10.1007/s00705-013-1768-6. PMC 4066373. PMID 23812617.
  2. ^ "Virus Taxonomy: 2019 Release". talk.ictvonline.org. International Committee on Taxonomy of Viruses. Retrieved 25 April 2020.
  3. ^ Koonin EV, Dolja VV, Krupovic M, Varsani A, Wolf YI, Yutin N, Zerbini M, Kuhn JH (October 2019). "Create a megataxonomic framework, filling all principal taxonomic ranks, for DNA viruses encoding vertical jelly roll-type major capsid proteins". ICTV Proposal (Taxoprop): 2019.003G. doi:10.13140/RG.2.2.14886.47684.
  4. ^ Colson P, de Lamballerie X, Fournous G, Raoult D (2012). "Reclassification of giant viruses composing a fourth domain of life in the new order Megavirales". Intervirology. 55 (5): 321–332. doi:10.1159/000336562. PMID 22508375.
  5. ^ Iyer, L. M.; Aravind, L.; Koonin, E. V. (December 2001). "Common Origin of Four Diverse Families of Large Eukaryotic DNA Viruses". Journal of Virology. 75 (23): 11720–34. doi:10.1128/JVI.75.23.11720-11734.2001. PMC 114758. PMID 11689653.