Closteroviridae

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Closteroviridae
Systematics
Classification : Viruses
Area : Riboviria
Empire : Orthornavirae
Phylum : Kitrinoviricota
Class : Alsuviricetes
Order : Martellivirales
Family : Closteroviridae
Taxonomic characteristics
Genome : (+) ssRNA linear
Baltimore : Group 4
Symmetry : helical
Cover : no
Left
NCBI  Taxonomy: 69973
ViralZone ( ExPASy , SIB): 34

The Closteroviridae (not to be confused with the Klosneuviruses , found in Klosterneuburg ) are a family of RNA viruses that infect plants .

construction

Virion

The virions (virus particles) of the Closteroviridae have a helical-filamentous capsid (twisted thread-like) with a variable length from about 650 nm to over 2200 nm and a diameter of 10-13 nm. The viral genome is single-stranded with positive polarity and a length of about 13 to 19 kilobases , with different segmentation of the genome. The genome is packaged in a capsid composed of the major capsid protein ( English major capsid protein is constructed MCP) and both sides of the minor capsid protein is capped.

Genome

Anticipated secondary structure of the 3 'pseudoknot in the Sweet Potato Chlorotic Stunt Virus

The Closteroviridae genome is one of the largest RNA genomes in plant viruses. It contains linearly arranged duplicates of coding sequences as well as partly non-viral sections (e.g. for proteases and the HSP70 ), which can be flexibly integrated through RNA recombination . Some species form subviral, small particles that contain only parts of the genome or subgenomic viral RNA. The genome of the Beet yellows virus (BYT) codes for the proteins ORF1a (contains the RNA polymerase ), ORF1ab (also contains the RNA polymerase), p6 , MP / Hsp70h , p64 , CPm , Cp , p20 and p21 .

Systematics

Internal system

The genera of the family differ in the segmentation of the genome and in the type of transmission. The genomes of the ampeloviruses are segmented in one piece and are transmitted by mealybugs and other scale insects, while the genome of the closteroviruses is one piece and is passed on by aphids and the genome of the crinivirus is two or three-part and is transmitted by the whitefly . The following breakdown of the Closteroviridae in Genera follows the requirements of the International Committee on Taxonomy of Viruses (ICTV) as of November 2018,

  • Family Closteroviridae

There are also a number of species that are not assigned to any genus, e.g. B. the Blueberry virus A

External system

In 2015, Koonin et al assigned the Closteroviridae taxonomically (due to their relationship) to the supergroup 'Alphavirus-like superfamily' they postulated. Sister group is thereafter the family Virgaviridae . The members of this proposed supergroup belong to different groups of the Baltimore classification , usually they are single-stranded RNA viruses of positive polarity ((+) ssRNA, Baltimore group 4), but there are also double-stranded representatives (marked with dsRNA, Find Baltimore Group 3).

This suggestion has now been replaced by the ICTV Master Species List # 35 of March 2020. A comparison of the cladograms can be found in Tymovirales §ICTV Master Species List # 35 .

literature

  • GP Martelli et al. : Family Closteroviridae . In: AMQ King, MJ Adams, EB Carstens, EJ Lefkowitz (eds.): Virus Taxonomy. Ninth Report of the International Committee on Taxonomy of Viruses. Amsterdam 2012 pp. 987ff, ISBN 978-0-12-384684-6
  • DM Knipe, Peter M. Howley , DE Griffin, (Eds.): Fields Virology. 5th edition, Lippincott Williams & Wilkins, Philadelphia 2007, ISBN 978-0-7817-6060-7 .

Web links

Individual evidence

  1. ↑ ICTV Master Species List 2018b v1 MSL # 34, Feb. 2019
  2. ↑ a b c d e ICTV: ICTV Master Species List 2019.v1 , New MSL including all taxa updates since the 2018b release, March 2020 (MSL # 35)
  3. ↑ R. Flores, P. Moreno, B. Falk, GP Martelli, WO Dawson: e-Book on Closteroviridae. In: Frontiers in microbiology. Volume 4, 2013, p. 411, ISSN  1664-302X . doi : 10.3389 / fmicb.2013.00411 . PMID 24409172 . PMC 3873501 (free full text).
  4. ↑ GP Martelli, AA Agranovsky, M. Bar-Joseph, D. Boscia, T. Candresse, RH Coutts, VV Dolja, BW Falk, D. Gonsalves, W. Jelkmann, AV Karasev, A. Minafra, S. Namba, HJ Vetten, GC Wisler, N. Yoshikawa: The family Closteroviridae revised. In: Archives of virology. Volume 147, Number 10, October 2002, pp. 2039-2044, ISSN  0304-8608 . doi : 10.1007 / s007050200048 . PMID 12376765 .
  5. ↑ L. Rubio, J. Guerri, P. Moreno: Genetic variability and evolutionary dynamics of viruses of the family Closteroviridae. In: Frontiers in microbiology. Volume 4, 2013, p. 151, ISSN  1664-302X . doi : 10.3389 / fmicb.2013.00151 . PMID 23805130 . PMC 3693128 (free full text).
  6. ↑ ICTV : Master Species List 2018a v1 , MSL (# 33) including all taxa updates since the 2017 release. Fall 2018
  7. ↑ SIB: Ampelovirus , on: ViralZone
  8. ↑ SIB: Closterovirus , on: ViralZone
  9. ↑ SIB: Crinivirus , on: ViralZone
  10. ↑ Since this group (referred to by the authors as English superfamily ) contains an order with the Tymovirales , their rank must be higher than this and should not be understood as a superfamily . Ranks higher than order were not given by the ICTV at the time of the work.
  11. ^ Eugene V. Koonin, Valerian V. Dolja, Mart Krupovic: Origins and evolution of viruses of eukaryotes: The ultimate modularity , in: Virology from May 2015; 479-480. 2-25, Epub March 12, 2015, PMC 5898234 (free full text), PMID 25771806