Inoviridae is a family of bacteriophage viruses. The genomes are composed of circular single-stranded DNA. Bacteria serve as natural hosts. There are, as of 2014, 43 defined species in this family, divided between two genera.[1][2] However, mining of genomic and metagenomic datasets using machine learning approach led to the discovery of 10,295 inovirus-like sequences in nearly all bacterial phyla across virtually every ecosystem, indicating that this group of viruses is much more diverse and widespread than originally appreciated.[3]

Virus classification e
(unranked): Virus
Phylum: incertae sedis
Class: incertae sedis
Order: incertae sedis
Family: Inoviridae


Group: ssDNA



Viruses in Inoviridae are non-enveloped, with rod or filament geometries. The diameter is around 7 nm, with a length of 2000 nm. Genomes are circular, around 8 kb in length. The genome codes for 4 to 10 proteins.[1]

Genus Structure Symmetry Capsid Genomic arrangement Genomic segmentation
Plectrovirus Rod-shaped Non-enveloped Circular Monopartite
Inovirus Rod-shaped Non-enveloped Circular Monopartite

Life cycleEdit

Viral replication is cytoplasmic. Entry into the host cell is achieved by pilus-mediated adsorption into the host cell. Replication follows the ssDNA rolling circle model. DNA-templated transcription is the method of transcription. The virus exits the host cell by viral extrusion. Bacteria serve as the natural host.[1]

Genus Host details Tissue tropism Entry details Release details Replication site Assembly site Transmission
Plectrovirus Bacteria None Pilus adsorption Secretion Cytoplasm Cytoplasm Pilus
Inovirus Gram-negative bacteria None Pilus adsorption Secretion Cytoplasm Cytoplasm Pilus


  1. ^ a b c "Viral Zone". ExPASy. Retrieved 15 June 2015.
  2. ^ a b ICTV. "Virus Taxonomy: 2014 Release". Retrieved 15 June 2015.
  3. ^ Roux, S; Krupovic, M; Daly, RA; Borges, AL; Nayfach, S; Schulz, F; Sharrar, A; Matheus Carnevali, PB; Cheng, JF; Ivanova, NN; Bondy-Denomy, J; Wrighton, KC; Woyke, T; Visel, A; Kyrpides, NC; Eloe-Fadrosh, EA (2019). "Cryptic inoviruses revealed as pervasive in bacteria and archaea across Earth's biomes". Nature Microbiology. doi:10.1038/s41564-019-0510-x. PMID 31332386.

External linksEdit