Hokovirus

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"Hokovirus"
Systematics
Classification : Viruses
Area : Varidnaviria
Empire : Bamfordvirae
Phylum : Nucleocytoviricota
Class : Megaviricetes
Order : Impersonal
Family : Mimiviridae
Subfamily : "Klosneuvirinae" ?
Genre : "Hokovirus"
Taxonomic characteristics
Genome : dsDNA
Baltimore : Group 1
Scientific name
"Hokovirus"
Short name
HokV / HKV
Left
NCBI  Taxonomy: 1977636

" Hokovirus " ( HokV , also HKV ) is a proposed genus of giant viruses in the phylum Nucleocytoviricota (formerly Nucleocytoplasmic large DNA viruses , NCLDV ) from the family of Mimiviridae with only one species, " Hokovirus HKV1 ". Like all these giant viruses, they have a genome made up of double-stranded DNA (dsDNA). The genus was found in the analysis of metagenome samples from bottom sediments of deposits in the sewage treatment plant in Klosterneuburg near Vienna, Austria. Together with the Hokovirus , Schulz et al. In 2017, three additional virus genera identified, " Klosneuvirus ", " Catovirus " and " Indivirus ", which are collectively referred to as Klosneuviruses (proposed family " Klosneuvirinae ").

Genome

“ Hokovirus ” has a large genome of 1,326,229 base pairs (bp) and is predicted to encode 1,022 proteins , that is 881 gene families. This means that “ Hokovirus ” has the third largest genome among the toilet viruses mentioned after “ Klosneuvirus ” (1.57 million bp, 1,272 gene families) and “ Catovirus ” (1.53 million bp). The GC content is 21.4%, comparable to that of two other giant viruses, Cafeteria roenbergensis virus (CroV) and “ Choanovirus 1 ” (ChoanoV1), these have 23% and 22% respectively.

Hosts

The metagenomic analysis of the ribosomal 18S rRNA further showed that their hosts are (at least) close to simple Cercozoa .

Systematics

As of April 2020, " Hokovirus " is not yet registered by the International Committee on Taxonomy of Viruses (ICTV) ( Master Species List # 35). The National Center for Biotechnology Information (NCBI) sees the genus " Hokovirus " with the species " Hokovirus HKV1 " in the family of Mimiviridae .

While the affiliation of all four virus genera found in Klosterneuburg to the Mimiviridae is undisputed, the exact topology of the relationships within this family is currently still being discussed. Usually, as in Schulz et al. (2017) placed in a proposed subfamily " Klosneuvirinae ".

Some authors (CNS 2018) see the toilet new viruses including the “ Bodo saltans virus ” (BsV) in close relation to the cafeteria roenbergensis virus (CroV) and summarize them in a temporary subfamily called “ Aquavirinae ”. Another suggestion is to put all of them together with the mimiviruses (with mimivirus and “ megavirus ”) in a larger subfamily “ Megavirinae ”.

While the NCBI sees the “ Bodo saltans virus ” (BsV) as a species in the genus “ Klosneuvirus ”, Disa Bäckström et al. (2019), Fig. 3, a system of toilet new viruses with the " Catovirus " as the closest relative of BsV among the four original toilet new viruses. Cladograms for the internal systematics of the toilet new viruses can be found under Klos new virus §Systematics .

Individual evidence

  1. ↑ a b c d e f ICTV: ICTV Master Species List 2019.v1 , New MSL including all taxa updates since the 2018b release, March 2020 (MSL # 35)
  2. ↑ a b NCBI : Hokovirus (genus), date of access: August 21, 2019
  3. ↑ a b c d Frederik Schulz, Natalya Yutin, Natalia N. Ivanova, Davi R. Ortega, Tae Kwon Lee, Julia Vierheilig, Holger Daims, Matthias Horn, Michael Wagner: Giant viruses with an expanded complement of translation system components . In: Science . 356, No. 6333, April 7, 2017, ISSN  0036-8075 , pp. 82-85. doi : 10.1126 / science.aal4657 .
  4. ↑ David M. Needham, Susumu Yoshizawa, Toshiaki Hosaka, Camille Poirier, Chang Jae Choi, Elisabeth Hehenberger, Nicholas AT Irwin, Susanne Wilken, Cheuk-Man Yung, Charles Bachy, Rika Kurihara, Yu Nakajima, Keiichi Kojima, Tomomi Kimura-Someya , Guy Leonard, Rex R. Malmstrom, Daniel R. Mende, Daniel K. Olson, Yuki Sudo, Sebastian Sudek, Thomas A. Richards, Edward F. DeLong, Patrick J. Keeling, Alyson E. Santoro, Mikako Shirouzu, Wataru Iwasaki , Alexandra Z. Worden: A distinct lineage of giant viruses brings a rhodopsin photosystem to unicellular marine predators , in: PNAS, 23 September 2019, doi: 10.1073 / pnas.1907517116 , ISSN 0027-8424, here: Supplement 1 (xlsx)
  5. ↑ Center national de la recherche scientifique (CNS): List of the main “giant” viruses known as of today , Université Aix Marseille, April 18, 2018
  6. ↑ CM Deeg, ECT Chow, CA Suttle: The kinetoplastid-infecting Bodo saltans virus (BsV), a window into the most abundant giant viruses in the sea . In: eLife . 7, 2018, p. E33014. doi : 10.7554 / eLife.33014 .
  7. ↑ NCBI : Bodo saltans virus (species), date of access: August 2, 2019
  8. ↑ Disa Bäckström, Natalya Yutin, Steffen L. Jørgensen, Jennah Dharamshi, Felix Homa, Katarzyna Zaremba-Niedwiedzka, Anja Spang, Yuri I. Wolf, Eugene V. Koonin, Thijs JG Ettema; Richard P. Novick (Ed.): Virus Genomes from Deep Sea Sediments Expand the Ocean Megavirome and Support Independent Origins of Viral Gigantism , in: mBio Vol. 10 No. 2 2019, doi: 10.1128 / mBio.02497-18

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