Editing DNA virus (section)

===''Duplodnaviria''===
[[File:Duplodnaviria virion morphology.jpg|thumb|Illustrated sample of ''Duplodnaviria'' virions]]
''[[Duplodnaviria]]'' contains dsDNA viruses that encode a major capsid protein (MCP) that has the HK97 fold. Viruses in the realm also share a number of other characteristics involving the capsid and capsid assembly, including an icosahedral capsid shape and a terminase enzyme that packages viral DNA into the capsid during assembly. Two groups of viruses are included in the realm: tailed bacteriophages, which infect prokaryotes and are assigned to the order ''[[Caudovirales]]'', and herpesviruses, which infect animals and are assigned to the order ''[[Herpesvirales]]''.<ref name=duplo />

''Duplodnaviria'' is a very ancient realm, perhaps predating the [[last universal common ancestor]] (LUCA) of cellular life. Its origins not known, nor whether it is monophyletic or polyphyletic. A characteristic feature is the HK97-fold found in the MCP of all members, which is found outside the realm only in [[encapsulin]]s, a type of nanocompartment found in bacteria: this relation is not fully understood.<ref name=duplo /><ref name=krupovic >{{cite journal|vauthors=Krupovic M, Koonin EV|date=21 March 2017|title=Multiple origins of viral capsid proteins from cellular ancestors|journal=Proc Natl Acad Sci U S A|volume=114|issue=12|pages=E2401–E2410|doi=10.1073/pnas.1621061114|pmc=5373398|pmid=28265094|bibcode=2017PNAS..114E2401K |doi-access=free}}</ref><ref name=luca >{{cite journal|last1=Krupovic|first1=M|last2=Dolja|first2=VV|last3=Koonin|first3=EV|title=The LUCA and its complex virome.|journal=Nat Rev Microbiol|date=14 July 2020|volume=18|issue=11|pages=661–670|doi=10.1038/s41579-020-0408-x|pmid=32665595|s2cid=220516514|url=https://bpp.oregonstate.edu/sites/agscid7/files/bpp/attachments/lucavirome2020.pdf |archive-url=https://web.archive.org/web/20201027183841/https://bpp.oregonstate.edu/sites/agscid7/files/bpp/attachments/lucavirome2020.pdf |archive-date=2020-10-27 |url-status=live|access-date=24 September 2020}}</ref>

The relation between caudoviruses and herpesviruses is also uncertain: they may share a common ancestor or herpesviruses may be a divergent clade from the realm ''Caudovirales''. A common trait among duplodnaviruses is that they cause latent infections without replication while still being able to replicate in the future.<ref>{{cite journal|vauthors=Weidner-Glunde M, Kruminis-Kaszkiel E, Savanagoudar M|date=February 2020|title=Herpesviral Latency—Common Themes|journal=Pathogens|volume=9|issue=2|pages=125|doi=10.3390/pathogens9020125|pmc=7167855|pmid=32075270|doi-access=free}}</ref><ref>{{cite web|title=Virus latency|url=https://viralzone.expasy.org/3970|website=ViralZone|publisher=Swiss Institute of Bioinformatics|access-date=24 September 2020}}</ref> Tailed bacteriophages are ubiquitous worldwide,<ref>{{cite journal|vauthors=Andrade-Martínez JS, Moreno-Gallego JL, Reyes A|date=August 2019|title=Defining a Core Genome for the Herpesvirales and Exploring their Evolutionary Relationship with the Caudovirales|journal=Sci Rep|volume=9|issue=1|pages=11342 |doi=10.1038/s41598-019-47742-z|pmc=6683198|pmid=31383901|bibcode=2019NatSR...911342A}}</ref> important in marine ecology,<ref>{{cite journal|vauthors=Wilhelm SW, Suttle CA|date=October 1999|title=Viruses and Nutrient Cycles in the Sea: Viruses play critical roles in the structure and function of aquatic food webs|journal=BioScience|volume=49|issue=10|pages=781–788|doi=10.2307/1313569|jstor=1313569|doi-access=free}}</ref> and the subject of much research.<ref>{{cite journal|vauthors=Keen EC|date=January 2015|title=A century of phage research: Bacteriophages and the shaping of modern biology|journal=BioEssays|volume=37|issue=1|pages=6–9|doi=10.1002/bies.201400152|pmc=4418462|pmid=25521633}}</ref> Herpesviruses are known to cause a variety of epithelial diseases, including [[herpes simplex]], [[chickenpox]] and [[shingles]], and [[Kaposi's sarcoma]].<ref>{{cite journal|vauthors=Kukhanova MK, Korovina AN, Kochetkov SN|date=December 2014|title=Human herpes simplex virus: life cycle and development of inhibitors|journal=Biochemistry (Mosc)|volume=79|issue=13|pages=1635–1652|doi=10.1134/S0006297914130124|pmid=25749169|s2cid=7414402}}</ref><ref>{{cite journal|vauthors=Gershon AA, Breuer J, Cohen JI, Cohrs RJ, Gershon MD, Gilden D, Grose C, Hambleton S, Kennedy PG, Oxman MN, Seward JF, Yamanishi K|date=2 July 2015|title=Varicella zoster virus infection|journal=Nat Rev Dis Primers|volume=1|pages=15016|doi=10.1038/nrdp.2015.16|pmc=5381807|pmid=27188665}}</ref><ref>{{cite journal|vauthors=O'Leary JJ, Kennedy MM, McGee JO|date=February 1997|title=Kaposi's sarcoma associated herpes virus (KSHV/HHV 8): epidemiology, molecular biology and tissue distribution|journal=Mol Pathol|volume=50|issue=1|pages=4–8|doi=10.1136/mp.50.1.4|pmc=379571|pmid=9208806}}</ref>