Globuloviridae

Negative-contrast electron micrographs of virions of Pyrobaculum spherical virus (PSV, genus Alphaglobulovirus). (Left) Intact virions; arrows indicate spherical protrusions. (Right) Partially disrupted virions extruding disordered nucleoprotein core. The bars represent 100 nm. Modified from (Häring et al., 2004; provided by ICTV).

Globuloviridae is a family of hyperthermophilic archaeal viruses. Crenarchaea of the genera Pyrobaculum and Thermoproteus serve as natural hosts. There are four species in this family, assigned to a single genus, Alphaglobulovirus.^[1][2][3]

Taxonomy

The family contains one genus which contains four species:^[3]

• Alphaglobulovirus
  • Alphaglobulovirus PSV
  • Alphaglobulovirus PSV1
  • Alphaglobulovirus TSPV1
  • Alphaglobulovirus TTSV1

Structure

Virions in the Globuloviridae are spherical and enveloped. The diameter is around 100 nm.^[1][2]

Genome organization of Pyrobaculum spherical virus (PSV) showing location, sizes and direction of putative genes.

Genomes are linear dsDNA and non-segmented, around 20–30kb in length.^[1][2]

Life cycle

Viral replication is cytoplasmic. DNA-templated transcription is the method of transcription. Pyrobaculum and Thermoproteus archaea serve as the natural host. Transmission routes are passive diffusion.^[1]

References

• Häring M, Peng X, Brügger K, Rachel R, Stetter KO, Garrett RA, Prangishvili D (2004). "Morphology and genome organization of the virus PSV of the hyperthermophilic archaeal genera Pyrobaculum and Thermoproteus: a novel virus family, the Globuloviridae". Virology. 323 (2): 233–242. doi:10.1016/j.virol.2004.03.002. PMID 15193919.