Mrz 23, 2020
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Coronaviridae

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Coronaviridae is a family of enveloped, positive-sense, single-stranded RNA viruses. The viral genome is 26–32 kilobases in length. The particles are typically decorated with large (~20 nm), club- or petal-shaped surface projections (the “peplomers” or “spikes”), which in electron micrographs of spherical particles create an image reminiscent of the solar corona.

Virology

Diagram of coronavirus virion structure

The 5′ and 3′ ends of the genome have a cap and poly(A) tract, respectively. The viral envelope, obtained by budding through membranes of the endoplasmic reticulum (ER) or Golgi apparatus, invariably contains two virus-specified (glyco)protein species, S and M. Glycoprotein S comprises the large surface projections, while M is a triple-spanning transmembrane protein. Toroviruses and a select subset of coronaviruses (in particular the members of subgroup A in the genus Betacoronavirus) possess, in addition to the peplomers composed of S, a second type of surface projections composed of the hemagglutinin-esterase protein. Another important structural protein is the phosphoprotein N, which is responsible for the helical symmetry of the nucleocapsid that encloses the genomic RNA.[1]

Taxonomy

The family Coronaviridae is organized in 2 sub-families, 5 genera, 23 sub-genera and about 40 species:[2]

  • Coronaviridae
    • Orthocoronavirinae[3]
    • Letovirinae
      • Alphaletovirus
        • Milecovirus
          • Microhyla letovirus 1

illustration of coronavirus virion

Coronavirus

Illustration of a coronavirus

Coronavirus is the common name for Coronaviridae and Orthocoronavirinae, also called Coronavirinae.[4][5] Coronaviruses cause diseases in mammals and birds. In humans, the viruses cause respiratory infections, including the common cold, which are typically mild, though rarer forms such as SARS, MERS and COVID-19 can be lethal. Symptoms vary in other species: in chickens, they cause an upper respiratory disease, while in cows and pigs coronaviruses cause diarrhea. There are no vaccines or antiviral drugs to prevent or treat human coronavirus infections. They are enveloped viruses with a positive-sense single-stranded RNA genome and a nucleocapsid of helical symmetry. The genome size of coronaviruses ranges from approximately 26 to 32 kilobases, the largest for a RNA virus. The name “coronavirus” is derived from the Ancient Greek ‘κορώνη’, meaning crown or halo, which refers to the characteristic appearance of the virus particles (virions): they have a fringe reminiscent of a crown or of a solar corona.

Orthocoronavirinae taxonomy

  • Orthocoronavirinae
    • Alphacoronavirus
      • Colacovirus
        • Bat coronavirus CDPHE15
      • Decacovirus
        • Bat coronavirus HKU10
        • Rhinolophus ferrumequinum alphacoronavirus HuB-2013
      • Duvinacovirus
        • Human coronavirus 229E
      • Luchacovirus
        • Lucheng Rn rat coronavirus
      • Minacovirus
        • Ferret coronavirus
        • Mink coronavirus 1
      • Minunacovirus
        • Miniopterus bat coronavirus 1
        • Miniopterus bat coronavirus HKU8
      • Myotacovirus
        • Myotis ricketti alphacoronavirus Sax-2011
      • Nyctacovirus
        • Nyctalus velutinus alphacoronavirus SC-2013
      • Pedacovirus
        • Porcine epidemic diarrhea virus
        • Scotophilus bat coronavirus 512
      • Rhinacovirus
        • Rhinolophus bat coronavirus HKU2
      • Setracovirus
        • Human coronavirus NL63
        • NL63-related bat coronavirus strain BtKYNL63-9b
      • Tegacovirus
        • Alphacoronavirus 1 – type species
    • Betacoronavirus
      • Embecovirus
        • Betacoronavirus 1
          • Human coronavirus OC43
        • China Rattus coronavirus HKU24
        • Human coronavirus HKU1
        • Murine coronavirus – type species
      • Hibecovirus
        • Bat Hp-betacoronavirus Zhejiang2013
      • Merbecovirus
        • Hedgehog coronavirus 1
        • Middle East respiratory syndrome-related coronavirus (MERS-CoV)
        • Pipistrellus bat coronavirus HKU5
        • Tylonycteris bat coronavirus HKU4
      • Nobecovirus
        • Rousettus bat coronavirus GCCDC1
        • Rousettus bat coronavirus HKU9
      • Sarbecovirus
        • Severe acute respiratory syndrome-related coronavirus
          • Severe acute respiratory syndrome coronavirus (SARS-CoV)
          • Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19)
    • Deltacoronavirus
      • Andecovirus
        • Wigeon coronavirus HKU20
      • Buldecovirus
        • Bulbul coronavirus HKU11 – type species
        • Porcine coronavirus HKU15
        • Munia coronavirus HKU13
        • White-eye coronavirus HKU16
      • Herdecovirus
        • Night heron coronavirus HKU19
      • Moordecovirus
        • Common moorhen coronavirus HKU21
    • Gammacoronavirus
      • Cegacovirus
        • Beluga whale coronavirus SW1
      • Igacovirus
        • Avian coronavirus – type species

  • Coronaviridae
  • Corona Warriors
  • 19. Coronaviridae
  • Coronaviruses
  • Focus on Coronaviruses
  • Viralzone: Coronaviridae
  • Virus Pathogen Database and Analysis Resource (ViPR): Coronaviridae
  • ICTV


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