Sobemovirus

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Benyvirus
Virus classification
Group: Group IV ((+)ssRNA)
Family: Unassigned
Genus: Sobemovirus
Species

Southern cowpea mosaic virus

The Sobemovirus is a genus of a virus with no family.

Virology[edit]

The virion capsids are non-enveloped, round and isometric, with a diameter of 25–33 nm.

The genome is a single piece of linear, positive-sense, single-stranded RNA, 4100–5700 nucleotides in length.[1] The genome encodes five open reading frames: ORF1, ORFs 2a and 2b, ORF3 and ORFx.[2]

ORF1 encodes P1 which plays a role in suppression of silencing and virus movement.

ORFs 2a and 2b encode the replicational polyproteins P2a and P2ab. Translation of ORF2a from the genomic RNA is dependent on a leaky scanning mechanism.

ORF3 encodes the coat protein.

ORFx is conserved in all sobemoviruses. It overlaps the 5' end of ORF2a in the +2 reading frame and also extends some distance upstream of ORF2a. It lacks an AUG initiation codon and its expression is predicted to depend on low level initiation at near-cognate non-AUG codons, such as CUG, by a proportion of the ribosomes that are scanning the region between the ORF1 and ORF2a initiation codons. Its function is unknown but it appears to be essential for infection.

Taxonomy[edit]

The Southern cowpea mosaic virus is the type species.

References[edit]

  1. ^ Index of Viruses—Sobemovirus (2006). In: ICTVdB—The Universal Virus Database, version 4. Büchen-Osmond, C (Ed), Columbia University, New York, USA.
  2. ^ Ling R, Pate AE, Carr JP, Firth AE. An essential fifth coding ORF in the sobemoviruses. Virology pii: S0042-6822(13)00314-0. doi: 10.1016/j.virol.2013.05.033

External links[edit]