Podoviridae is a family of viruses in the order Caudovirales. Bacteria serve as natural hosts. There are currently 132 species in this family, divided among 3 subfamilies and 45 genera. This family is characterized by having very short, noncontractile tails.
Structure
Viruses in Podoviridae are non-enveloped, with icosahedral and head-tail geometries. The diameter is around 60 nm, and consists of 72 capsomers. The head protein has a molecular mass of ~38 kiloDaltons and is present in 460 copies per virion. There are 9 structural proteins. The tail is non-contractile and has 6 short subterminal fibers. It is thick and rod-shaped and built of stacked disks. The maximum length is ~17 nm. The double strandedDNA genome is linear, around 40-42kb in length, and encodes ~55 genes. The guanine + cytosine content is ~50%. It has terminally redundantsequences and is nonpermuted. By weight, the genome constitutes ~50% of the viron. The genome encodes 9 structural proteins, an adenylated transferase B typeDNA polymerase and an RNA polymerase. Three internal proteins constitute the polymerase complex. Two classes of genes are recognized. This classification is based on the timing of transcription that is temporally regulated. Genes with related functions are clustered together. Genome replication is bidirectional.
Life cycle
Viral replication is cytoplasmic. Entry into the host cell is achieved by adsorption into the host cell. Replication follows the DNA strand displacement model. DNA-templated transcription is the method of transcription. The virus exits the host cell by lysis, and holin/endolysin/spanin proteins. Bacteria serve as the natural host. Transmission routes are passive diffusion.
Taxonomy
Genera within this family have ~40% homology between corresponding proteins. Subfamilies have ~20% homology between corresponding proteins. The following subfamilies and their genera are recognized :
Picovirinae
*Capunavirus
*Negarvirus
*Salasvirus
*Species unassigned to a genus in Picovirinae: Actinomyces virus Av1 and Mycoplasma virus P1
Rakietenvirinae
*Andhravirus
*Rosenblumvirus
Sepvirinae
*Diegovirus
*Oslovirus
*Traversvirus
The following genera are not assigned to a subfamily:
Baltimorevirus
Bjornvirus
Bruynoghevirus
Enhodamvirus
Enquatrovirus
Fipvunavirus
Fischettivirus
Gamaleyavirus
Giessenvirus
Hollowayvirus
Ithacavirus
Jasminevirus
Johnsonvirus
Jwalphavirus
Kafunavirus
Kelquatrovirus
Kochitakasuvirus
Krylovvirus
Kuravirus
Lederbergvirus
Lessievirus
Lightbulbvirus
Litunavirus
Luzseptimavirus
Mukerjeevirus
Myxoctovirus
Pagevirus
Perisivirus
Rauchvirus
Ryyoungvirus
Schmidvirus
Shizishanvirus
Skarprettervirus
Sortsnevirus
Uetakevirus
Vicosavirus
Xuquatrovirus
The following species are unassigned to a genus:
Hamiltonella virus APSE1
Lactococcus virus KSY1
Phormidium virus WMP3
Phormidium virus WMP4
Pseudomonas virus 119X
Roseobacter virus SIO1
Vibrio virus VpV262
Proposed genera
The following genera have been proposed but are not currently ratified by the International Committee on Taxonomy of Viruses:
Genus 119xlikevirus; type species: Pseudomonas phage 119X
*Species:
**Pseudomonas phage 119X
Genus Cba40unalikevirus; type species: Cellulophaga phage phi40:1
*Species:
**Cellulophaga phage phi40:1
**Cellulophaga phage phi38:1
Genus Cba183likevirus; type species: Cellulophaga phage phi18:3
*Species:
**Cellulophaga phage phi18:3
**Cellulophaga phage phi13:2
**Cellulophaga phage phi19:3
**Cellulophaga phage phi46:3
Genus Cba142likevirus; type species: Cellulophaga phage phi14:2
*Species:
**Cellulophaga phage phi14:2
Genus Cba4unalikevirus; type species: Cellulophaga phage phi4:1
*Species:
**Cellulophaga phage phi4:1
**Cellulophaga phage phi17:2
Genus Cpvunalikevirus; type species: Clostridium phage CpV1
*Species:
**Clostridium phage CpV1
Genus Gap227likevirus; type species: Cronobacter phage vB CsaP GAP227
*Species:
**Cronobacter phage vB CsaP GAP227
**Yersinia phage phiR8-01
**Yersinia phage phi80-18
**Aeromonas phage phiAS7
Genus P60likevirus ; type species: Synechococcus phage P60
*Species:
**Synechococcus phage P60
Genus pelagiphages ; type species: Pelagibacter phage HTVC010P
*Species:
**Pelagibacter phage HTVC010P MAR122
**Pelagibacter phage HTVC010P MAR123
**Pelagibacter phage HTVC010P MAR124
Genus Vp2likevirus; type species: Vibrio phage VP2
*Species:
**Vibrio phage VP2
Genus Ys6unalikevirus; type species: Weissella phage phiYS61
*Species:
**Weissella phage phiYS61
In 2017, it was proposed to add crAssphage to this family.