08-31-2021-2304 - Nucleocytoviricota nucleocytoplasmic large DNA viruses (NCLDV) virus plasmid plasma genes involved in DNA repair, DNA replication, transcription, and translation nucleus cytoplasm proliferating cell nuclear antigen topoisomerase II A, FLAP endonuclease factor bamford varidnaviria mega ancestor NCLDV genome

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 endonucleaseand the processing factor proliferating cell nuclear antigen. Other proteins include DNA dependent RNA polymerase II and transcription factor II B. 

Nucleocytoviricota
Virus classification
(unranked):	Virus
Realm:	Varidnaviria
Kingdom:	Bamfordvirae
Phylum:	Nucleocytoviricota
Classes
See text
Synonyms
Megavirales[1]

Taxonomy[edit]

The following classes are recognized, under which are orders that contain families mentioned in this article:

• Megaviricetes
  • Pimascovirales
    • Ascoviridae
    • Iridoviridae
    • Marseilleviridae
    • (Pithoviridae?) – by etymology of Pimascovirales
    • (Mininucleoviridae?) – by phylogeny
  • Imitervirales
    • Mimiviridae
  • Algavirales
    • Phycodnaviridae
    • (Pandoraviridae?) – by phylogeny
• Pokkesviricetes
  • Asfuvirales
    • Asfarviridae
  • Chitovirales
    • Poxviridae

The unrecognized families are parenthesized and placed in the most likely location.

https://en.wikipedia.org/wiki/Nucleocytoviricota