Tombusvirus

VIRION

Non-enveloped, spherical, icosahedral, about 28-34 nm in diameter, capsid with a T=3 icosahedral symmetry. 30 hexameric capsomers per nucleocapsid (virion composed of 180 protein subunits).

GENOME

Monopartite, linear, ssRNA(+) genome of 4-5.4 kb, which lacks a cap structure and a poly(A)tail.

GENE EXPRESSION

The virion RNA is infectious and serves as both the genome and viral messenger RNA. Two 5'-proximal ORFs are directly translated to produce the viral constituents of the replicase complex. RdRp is translated through suppression of termination at the end of ORF1. The downstream genes encoding the movement protein, viral suppressor of RNA silencing (VSR) and capsid proteins are translated from subgenomic RNAs.
Cap-independent translation is mediated possibly through the interaction between a 3'-cap-independent translation element and a 5’UTR stem-loop.

REPLICATION

CYTOPLASMIC

  1. Virus penetrates into the host cell.
  2. Uncoating, and release of the viral genomic RNA into the cytoplasm.
  3. The viral RNA is translated to produce the two proteins necessary for RNA synthesis (replication and transcription).
  4. Replication takes place in cytoplasmic viral factories. A dsRNA genome is synthesized from the genomic ssRNA(+).
  5. The dsRNA genome is transcribed/replicated thereby providing viral mRNAs/new ssRNA(+) genomes.
  6. The RdRp recognizes internal subgenomic promoters on the negative-sense RNA to transcribe the 3’co-terminal subgenomic RNAs that will generate the capsid and movement protein.
  7. The RdRp recognizes internal subgenomic promoters on the negative-sense RNA to transcribe the 3’co-terminal subgenomic RNAs that will generate the capsid protein, movement protein and viral suppressor of RNA silencing (VSR).
  8. Virus assembly in the cytoplasm.
  9. Viral movement protein probably mediates virion cell-to-cell transfer.

Host-virus interaction

Suppression of RNA silencing

Tombusviruses encode P19/P20 protein acting as a suppressor of RNA silencing .

Matching UniProtKB/Swiss-Prot entries

32 entries grouped by strain (browse by keywords)

All proteins are shown (view only 11 complete proteome entries)

4 entries

Tomato bushy stunt virus (strain Cherry) (TBSV) reference strain

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CAPSD_TBSVC Capsid protein (Coat protein) (p41)
MVP_TBSVC Movement protein (p22)
P19_TBSVC RNA silencing suppressor p19 (19 kDa symptom severity modulator)
RDRP_TBSVC RNA-directed RNA polymerase (EC 2.7.7.48) (Protein p92) [Cleaved into: Protein p33]

4 entries

Cucumber necrosis virus (CNV)

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CAPSD_CNV Capsid protein (Coat protein) (p41)
MVP_CNV Movement protein (p22)
P19_CNV RNA silencing suppressor p19 (19 kDa symptom severity modulator)
RDRP_CNV RNA-directed RNA polymerase (EC 2.7.7.48) (Protein p92) [Cleaved into: Protein p33]

4 entries

Cymbidium ringspot virus (CymRSV)

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CAPSD_CRV Capsid protein (Coat protein) (p41)
MVP_CRV Movement protein (p22)
P19_CRV RNA silencing suppressor p19 (19 kDa symptom severity modulator)
RDRP_CRV RNA-directed RNA polymerase (EC 2.7.7.48) (Protein p92) [Cleaved into: Protein p33]

3 entries

Artichoke mottled crinkle virus (AMCV)

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CAPSD_AMCV Capsid protein (Coat protein) (p41)
MVP_AMCV Movement protein (p22)
P19_AMCV RNA silencing suppressor p19 (19 kDa symptom severity modulator)

3 entries

Tomato bushy stunt virus (strain BS-3) (TBSV)

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CAPSD_TBSVB Capsid protein (Coat protein) (p41)
MVP_TBSVB Movement protein (p22)
P19_TBSVB RNA silencing suppressor p19 (19 kDa symptom severity modulator)

2 entries

Tomato bushy stunt virus (strain A23) (TBSV)

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MVP_TBSVA Movement protein (p22)
P19_TBSVA RNA silencing suppressor p19 (19 kDa symptom severity modulator)

2 entries

Tomato bushy stunt virus (strain B8) (TBSV)

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MVP_TBSV8 Movement protein (p22)
P19_TBSV8 RNA silencing suppressor p19 (19 kDa symptom severity modulator)

2 entries

Tomato bushy stunt virus (strain Ja6) (TBSV)

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MVP_TBSVJ Movement protein (p22)
P19_TBSVJ RNA silencing suppressor p19 (19 kDa symptom severity modulator)

2 entries

Tomato bushy stunt virus (strain Ja9) (TBSV)

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MP22_TBSVK Movement protein p22 (p21)
P19_TBSVK RNA silencing suppressor p19 (19 kDa symptom severity modulator)

2 entries

Tomato bushy stunt virus (strain type) (TBSV)

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MP22_TBSVT Movement protein p22 (p21)
P19_TBSVT RNA silencing suppressor p19 (19 kDa symptom severity modulator)

1 entry

Carnation Italian ringspot virus (CIRV)

P19_CIRV RNA silencing suppressor p19 (19 kDa symptom severity modulator)

1 entry

Havel river virus (HaRV)

P19_HARV RNA silencing suppressor p19 (19 kDa symptom severity modulator)

1 entry

Pear latent virus (PeLV)

P19_PLV RNA silencing suppressor p19 (19 kDa symptom severity modulator)

1 entry

Pelargonium necrotic spot virus (PeNSV)

P19_PENSV RNA silencing suppressor p19 (19 kDa symptom severity modulator)