ICTV Virus Taxonomy Profile: Pleolipoviridae

Abstract

Members of the family Pleolipoviridae (termed pleolipoviruses) are pseudo-spherical and pleomorphic archaeal viruses. The enveloped virion is a simple membrane vesicle, which encloses different types of DNA genomes of approximately 7–16 kbp (or kilonucleotides). Typically, virions contain a single type of transmembrane (spike) protein at the envelope and a single type of membrane protein, which is embedded in the envelope and located in the internal side of the membrane. All viruses infect extremely halophilic archaea in the class Halobacteria (phylum Euryarchaeota). Pleolipoviruses have a narrow host range and a persistent, non-lytic life cycle. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on the taxonomy of the Pleolipoviridae which is available at www.ictv.global/report/pleolipoviridae.

Novel haloarchaeal viruses from Lake Retba infecting Haloferax and Halorubrum species

“…HRPV10, HRPV11 and HRPV12 form a well‐supported clade with members of the genus Betapleolipovirus , namely Halorubrum virus HRPV‐3 and Halogeometricum virus HGPV‐1. The clade also includes Haloarcula virus HHPV3 and Natrinema virus SNJ2, two tentative members of the Betapleolipovirus genus (Liu et al ., ; Bamford et al ., ).…”

“…Membrane‐containing virions of pleolipoviruses resemble extracellular membrane vesicles able to carry the virus genome from host to host (Pietilä et al ., ). They represent a unique archaeal virus group with a recently established taxonomic position as the first family containing viruses with either single‐stranded (ss) or double‐stranded (ds) DNA genomes (linear or circular forms) (Pietilä et al ., ; Bamford et al ., ). The non‐lytic pleomorphic virus life cycle starts with fusion between the viral and host membranes and they exit the host cell most probably by budding, preserving the host membrane integrity (Svirskaite et al ., ; El Omari et al ., ).…”

Taxonomy of prokaryotic viruses: 2017 update from the ICTV Bacterial and Archaeal Viruses Subcommittee

“…The family Pleolipoviridae is now recognized as the first virus taxon in the newly established ICTV category for ssDNA/dsDNA Viruses. The summaries of the ICTV Report chapters are published in The Journal of General Virology [6,11,12].…”

The Unexplored Diversity of Pleolipoviruses: The Surprising Case of Two Viruses with Identical Major Structural Modules

“…Pleolipoviruses are rather newly-described, related pleomorphic viruses that infect extremely halophilic archaeal hosts from the genera Halorubrum , Haloarcula , or Halogeometricum [ 1 ]. At the time of writing, the family Pleolipoviridae comprises eight members and five related, but unclassified, pleomorphic viruses: Halorubrum pleomorphic virus 7 (HRPV-7), HRPV-8, Haloarcula pleomorphic virus 2 (HAPV-2), Natrinema virus SNJ2, and Haloarcula hispanica pleomorphic virus 3 (HHPV3) [ 1 , 2 , 3 , 4 ]. The viral family consists of three genera, Alphapleolipovirus , Betapleolipovirus , and Gammapleolipovirus , and is acknowledged by the International Committee on Taxonomy of Viruses (ICTV) as a virus family that contains related viruses with different nucleic acid types [ 1 ].…”

“…At the time of writing, the family Pleolipoviridae comprises eight members and five related, but unclassified, pleomorphic viruses: Halorubrum pleomorphic virus 7 (HRPV-7), HRPV-8, Haloarcula pleomorphic virus 2 (HAPV-2), Natrinema virus SNJ2, and Haloarcula hispanica pleomorphic virus 3 (HHPV3) [ 1 , 2 , 3 , 4 ]. The viral family consists of three genera, Alphapleolipovirus , Betapleolipovirus , and Gammapleolipovirus , and is acknowledged by the International Committee on Taxonomy of Viruses (ICTV) as a virus family that contains related viruses with different nucleic acid types [ 1 ]. Genomes of the known haloarchaeal pleomorphic viruses are approximately 7–17 kb in size and can be either circular single-stranded (ss) DNA, circular or linear double-stranded (ds) DNA, or circular dsDNA with single-stranded interruptions [ 1 , 5 ].…”