Non-enveloped, rod of filaments of 7nm in diameter and 700 to 2000nm in length. Helical capsid with adsorption proteins on one end.


Circular, ssDNA genome (+) of 4.5 to 8kb encoding for 4 to 10 proteins. Replication occurs via dsDNA intermediate and rolling circle.


Each gene is transcribed by host cellular machinery, via a specific promoter. Some genes end by a transcription terminator.



  1. Viral g3p protein mediates pilus-mediated adsorption of the virus onto host cell. Pilus retraction pulls the virion to the host internal membrane.
  2. The proteins of the capsid perform the injection of the viral DNA through bacterial membranes into cell cytoplasm.
  3. Host polymerase convert the (+)ssDNA viral genome into a covalently closed dsDNA called replicative form DNA (RF).
  4. dsDNA transcription by host RNA polymerase gives rise to viral mRNAs.
  5. Viral g2p protein nicks RF DNA strand at the origin of replication.
  6. (+) strand replication occurs by rolling circle.
  7. New (+)ssDNA genomes are converted into new RF molecules, and further transcription occurs.
  8. When enough g5p protein is synthesized, conversion into RF dsDNA is inhibited, as neo-synthesized genomic ssDNA is covered with g5p.
  9. g5p are replaced by g8p proteins to trigger the assembly of the viral capsid.
  10. New virions are secreted from host cell.
  11. Infected cells continue to divide and produce virions indefinitely.

Matching UniProtKB/Swiss-Prot entries

25 entries grouped by strain (browse by keywords)

13 entries

Spiroplasma virus SpV1-C74 (SpV1) reference strain

Select_all Deselect_all  
CAPSD_SPV1CPutative capsid protein ORF9
INTG_SPV1CPutative integrase ORF3
ORF10_SPV1CUncharacterized protein ORF10
ORF11_SPV1CUncharacterized protein ORF11
ORF12_SPV1CUncharacterized protein ORF12
ORF13_SPV1CUncharacterized protein ORF13
ORF14_SPV1CUncharacterized protein ORF14
ORF15_SPV1CUncharacterized protein ORF15
ORF1_SPV1CUncharacterized protein ORF1
ORF2_SPV1CUncharacterized protein ORF2
ORF4_SPV1CUncharacterized protein ORF4
ORF5_SPV1CUncharacterized protein ORF5
ORF7_SPV1CUncharacterized protein ORF7

12 entries

Spiroplasma virus SpV1-R8A2 B (SpV1) (Spiroplasma virus 1) reference strain

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CAPSD_SPV1RPutative capsid protein ORF9 (Gene 9 protein)
INTG_SPV1RPutative integrase ORF3 (Gene 3 protein)
ORF10_SPV1RUncharacterized protein ORF10 (Gene 10 protein)
ORF11_SPV1RUncharacterized protein ORF11 (Gene 11 protein)
ORF12_SPV1RUncharacterized protein ORF12 (Gene 12 protein)
ORF1_SPV1RUncharacterized protein ORF1 (Gene 1 protein)
ORF2_SPV1RUncharacterized protein ORF2 (Gene 2 protein)
ORF4_SPV1RUncharacterized protein ORF4 (Gene 4 protein)
ORF5_SPV1RUncharacterized protein ORF5 (Gene 5 protein)
ORF6_SPV1RUncharacterized protein ORF6 (Gene 6 protein)
ORF7_SPV1RUncharacterized protein ORF7 (Gene 7 protein)
ORF8_SPV1RUncharacterized protein ORF8 (Gene 8 protein)