Betaflexiviridae

VIRION

Non-enveloped, flexuous, filamentous, 600-1000 nm or more long and 12-13 nm in diameter.

GENOME

Linear ssRNA(+) genome of 6.5-9 kb in size. The 3' terminus is polyadenylated and, in some genera, the 5' end is capped. Encodes 2 to 6 proteins.

GENE EXPRESSION

The virion RNA is infectious and serves as both the genome and viral messenger RNA. RNA-dependent RNA polymerase (RdRp) is translated directly from the genomic RNA. The other ORFs are transcribed presumably as monocistronic subgenomic mRNAs (sgRNAs).

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 as a monocistronic mRNA to produce the RdRp (encoded by the 5'-proximal ORF).
  4. Replication occurs in 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. Internal subgenomic promoters are used to transcribe the sgRNAs. Traduction of these sgRNAs yields the capsid and movement proteins.
  7. Assembly of new virus particles.
  8. Triple gene block proteins (TGBp) allow cell-to-cell and long-distance movement.

Host-virus interaction

Suppression of RNA silencing

Potato virus M cysteine-rich protein (ORF6) and TGBp1 proteins act as suppressors of RNA silencing, the former inhibiting both local and systemic silencing, whereas the latter inhibits systemic silencing .

Grapevine virus A ORF5 p10 suppresses local and systemic RNA silencing .

Citrus leaf blotch virus movement protein acts as suppressor of RNA silencing .

Apple chlorotic leaf spot virus 50 kDa movement protein acts as a systemic suppressor of RNA silencing through phloem .

Matching UniProtKB/Swiss-Prot entries

55 entries grouped by protein (browse by keywords)

All proteins are shown (view only 28 complete proteome entries)

12 entries

Capsid protein (Coat protein) (CP)

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CAPSD_ACLSP
Apple chlorotic leaf spot virus (isolate plum P863) (ACLSV) reference strain
CAPSD_ASPVP
Apple stem pitting virus (isolate PA66) (ASPV) reference strain

Capsid protein (CP) (Coat protein)

CAPSD_CLBVS
Citrus leaf blotch virus (isolate Nagami kumquat/France/SRA-153/1984) (CLBV) reference strain

Capsid protein (CP) (Coat protein)

CAPSD_GVAIS
Grapevine virus A (isolate Is 151) (GVA) reference strain

Capsid protein (CP) (Coat protein)

CAPSD_PVMR
Potato virus M (strain Russian) (PVM) reference strain
CAPSD_ACLSA
Apple chlorotic leaf spot virus (isolate apple) (ACLSV)
CAPSD_CVB
Chrysanthemum virus B (CVB)
CAPSD_HELVS
Helenium virus S (HelVS)
CAPSD_LSV
Lily symptomless virus (LSV)
CAPSD_POPMV
Poplar mosaic virus (isolate ATCC Pv275) (PMV)
CAPSD_PVMG
Potato virus M (strain German) (PVM)
CAPSD_PVSP
Potato virus S (strain Peruvian)

2 entries

Movement protein (MP)

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MOVP_CLBVS
Citrus leaf blotch virus (isolate Nagami kumquat/France/SRA-153/1984) (CLBV) reference strain

Putative movement protein (MP) (Cell-to-cell transport protein)

MOVP_GVAIS
Grapevine virus A (isolate Is 151) (GVA) reference strain

4 entries

Probable movement protein (EC 3.4.21.-) (36 kDa protein) (ORF2 protein)

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MP_ACLSP
Apple chlorotic leaf spot virus (isolate plum P863) (ACLSV) reference strain

Putative movement protein (50.8 kDa protein) (ORF2 protein)

MP_ASGVP
Apple stem grooving virus (strain P-209) (ASGV) reference strain
MP_ACLSA
Apple chlorotic leaf spot virus (isolate apple) (ACLSV)

Putative movement protein (50.4 kDa protein) (ORF2 protein)

MP_ASGVK
Apple stem grooving virus (strain Korea) (ASGV)

Putative movement protein (EC 3.4.21.-) (36 kDa protein) (ORF2 protein)

1 entry

Uncharacterized ORF2 protein

ORF2_GVAIS
Grapevine virus A (isolate Is 151) (GVA) reference strain

2 entries

Genome polyprotein (241 kDa polyprotein) (ORF1 polyprotein)

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POLG_ASGVP
Apple stem grooving virus (strain P-209) (ASGV) reference strain
POLG_ASGVK
Apple stem grooving virus (strain Korea) (ASGV)

7 entries

RNA replication polyprotein (ORF1 protein)

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RDRP_ACLSP
Apple chlorotic leaf spot virus (isolate plum P863) (ACLSV) reference strain

RNA-directed RNA polymerase (EC 2.7.7.48) (216.5 kDa protein) (ORF1 protein) (RNA replicase)

RDRP_ASPVP
Apple stem pitting virus (isolate PA66) (ASPV) reference strain
RDRP_BBSCV
Blueberry scorch virus (BBScV) reference strain

RNA replication polyprotein (223 kDa protein) (ORF1 protein)

RDRP_CLBVS
Citrus leaf blotch virus (isolate Nagami kumquat/France/SRA-153/1984) (CLBV) reference strain
RDRP_GVAIS
Grapevine virus A (isolate Is 151) (GVA) reference strain

RNA replication protein

RDRP_PVMR
Potato virus M (strain Russian) (PVM) reference strain
RDRP_ACLSA
Apple chlorotic leaf spot virus (isolate apple) (ACLSV)

RNA-directed RNA polymerase (EC 2.7.7.48) (216.5 kDa protein) (ORF1 protein) (RNA replicase)

6 entries

Movement and silencing protein TGBp1 (25 kDa protein) (Silencing suppressor P25) (Triple gene block 1 protein) (TGBp1)

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TGB1_ASPVP
Apple stem pitting virus (isolate PA66) (ASPV) reference strain
TGB1_PVMR
Potato virus M (strain Russian) (PVM) reference strain
TGB1_CVB
Chrysanthemum virus B (CVB)
TGB1_LSV
Lily symptomless virus (LSV)
TGB1_POPMV
Poplar mosaic virus (isolate ATCC Pv275) (PMV)
TGB1_PVSP
Potato virus S (strain Peruvian)

5 entries

Movement protein TGB2 (12 kDa protein) (Triple gene block 2 protein) (TGBp2)

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TGB2_ASPVP
Apple stem pitting virus (isolate PA66) (ASPV) reference strain

Movement protein TGB2 (Triple gene block 2 protein) (TGBp2)

TGB2_PVMR
Potato virus M (strain Russian) (PVM) reference strain
TGB2_CVB
Chrysanthemum virus B (CVB)
TGB2_LSV
Lily symptomless virus (LSV)
TGB2_PVSP
Potato virus S (strain Peruvian)

7 entries

Movement protein TGBp3 (7 kDa protein) (Triple gene block 3 protein) (TGBp3)

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TGB3_ASPVP
Apple stem pitting virus (isolate PA66) (ASPV) reference strain

Movement protein TGBp3 (Triple gene block 3 protein) (TGBp3)

TGB3_PVMR
Potato virus M (strain Russian) (PVM) reference strain
TGB3_CLV
Carnation latent virus (CLV)
TGB3_CVB
Chrysanthemum virus B (CVB)
TGB3_LSV
Lily symptomless virus (LSV)
TGB3_POPMV
Poplar mosaic virus (isolate ATCC Pv275) (PMV)
TGB3_PVSP
Potato virus S (strain Peruvian)

9 entries

RNA silencing suppressor (10.7 kDa protein) (Putative nucleic acid-binding protein)

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VSR_GVAIS
Grapevine virus A (isolate Is 151) (GVA) reference strain

RNA silencing suppressor

VSR_PVMR
Potato virus M (strain Russian) (PVM) reference strain
VSR_CLV
Carnation latent virus (CLV)

RNA silencing suppressor (11.6 kDa protein) (Putative nucleic acid-binding protein)

VSR_CVB
Chrysanthemum virus B (CVB)

RNA silencing suppressor (12.6 kDa protein) (Putative nucleic acid-binding protein)

VSR_HELVS
Helenium virus S (HelVS)

RNA silencing suppressor (12.6 kDa protein) (Putative nucleic acid-binding protein)

VSR_LSV
Lily symptomless virus (LSV)

RNA silencing suppressor (16 kDa protein) (ORF6 protein) (Putative nucleic acid-binding protein)

VSR_POPMV
Poplar mosaic virus (isolate ATCC Pv275) (PMV)

RNA silencing suppressor (14 kDa protein) (Putative nucleic acid-binding protein)

VSR_PVMG
Potato virus M (strain German) (PVM)

RNA silencing suppressor (12 kDa protein) (Cysteine-rich protein) (CRP) (Nucleic acid-binding regulatory protein) (PR12)

VSR_PVSP
Potato virus S (strain Peruvian)