Bacteriophages: Lipid‐containing

Abstract

Viruses exhibit vast diversity in their form and function and are by far the most numerous (estimates 10 30 –10 32 ) organisms on earth. The largest group among viruses is bacteriophages, the viruses that infect bacteria, with over 5000 identified members. Majority of the phages are composed of protein and nucleic acid with a head–tail morphology. Polyhedral, filamentous or pleomorphic phages comprise only less than 4% of the described bacteriophages, and a minority of these have lipid constituents in addition to nucleic acid and protein. These lipid‐containing bacteriophages form a diverse group of viruses and they are classified in four virus families Corticoviridae , Cystoviridae , Plasmaviridae and Tectiviridae . The lipids can be either as the outermost layer of the virion or they can locate internally enclosed within the virus capsid. In both cases, the viral membranes are involved in cell entry processes. Key Concepts: The lipid‐containing bacteriophages are a diverse group of bacterial viruses. The lipid‐containing bacteriophages are sensitive to organic solvents and detergents. Lipids in the viral membrane have a bilayer structure. The virion proteins are all virus specific, but lipids are derived from host cytoplasmic membrane. During virus morphogenesis, the virus‐specific proteins exclude host proteins during formation of the viral membrane. The viral protein‐rich membranes have an essential role during entry mediating the translocation of the genome across the host cell envelopes.

Lipids of Archaeal Viruses

“…Chloroform treatment can, however, also abolish the infectivity of virions that have not been reported to contain lipids [ 35 ] and therefore further studies are always required. Low buoyant density is also an indicator of the lipid membrane in the virions [ 6 , 36 ]. Sudan Black B can be used to stain the polyacrylamide gel containing separated virion proteins and lipids [ 10 , 37 ].…”

“…Few viruses contain both the inner membrane as well as an envelope [ 1 ]. Lipid membranes of viruses have evolved into essential components of virions that in many cases seem to be involved in the initial stages of infection [ 4 – 6 ]. The majority of membrane containing viruses infect animals both vertebrate and invertebrate that do not have a cell wall surrounding the cytoplasmic membrane.…”

“…Enveloped viruses obtain the membrane during budding, that is, egress of the viral particles from the cells without disturbing the cell membrane integrity [ 15 ]. The inner membrane of prokaryotic viruses is presumed to be obtained from specific patches of host cytoplasmic membrane containing viral membrane proteins and mechanistically analogous to the formation of clathrin coated pits [ 6 , 16 – 18 ]. Consequently, enveloped viruses often exit the cells without lysis, whereas the viruses containing a membrane inside the capsid usually lyse the cells.…”

Chronic Release of Tailless Phage Particles from Lactococcus lactis

“…The group of tailless phages includes bacteriophages that have, in addition to nucleic acid and proteins, internal or external lipid constituents, a property originally associated with viruses infecting multicellular eukaryotes. Currently, the lipid-containing bacteriophages are classified into four families, Corticoviridae , Cystoviridae , Plasmaviridae , and Tectiviridae ( 19 ).…”

Good things come in small packages : delivery of vitamin K2 to human cells by extracellular vesicles from Lactococcus lactis

“…The group of tailless phages includes bacteriophages that have, in addition to nucleic acid and proteins, internal or external lipid constituents -a property originally associated with viruses infecting multicellular eukaryotes. Currently, the lipidcontaining bacteriophages are classified into four families, Corticoviridae, Cystoviridae, Plasmaviridae and Tectiviridae (Oksanen et al, 2010).…”