Virion: large, enveloped; Genome: non segmented, linear, double-stranded DNA. Asfarviridae

Description of Asfarviridae adapted from ICTVdb Virion Properties Morphology Virions consist of an envelope, a capsid, a core, and a nucleoprotein complex. During their life cycle, virions have an extracellular phase; can occur in two phenotypes. Virus capsid is enveloped. Virions are spherical and measure 175-215 nm in diameter. Intracellular virions are not enveloped. Capsid/nucleocapsid is round and exhibits icosahedral symmetry (T=189-217). The isometric capsid has a diameter of 172-191 nm. Capsids appear hexagonal in outline. The capsid surface structure does not reveal a regular pattern with distinctive features and consists of 1892-2172 capsomers; each capsomer measures 13 nm in diameter. Capsomers consist of a hexagonal base with a central cavity. The core is cylindrical. Physicochemical and Physical Properties Virions have a buoyant density in CsCl of 1.19-1.24 g cm-3. Nucleic Acid The genome is not segmented and contains a single molecule of linear double-stranded DNA. The complete genome is 170000-190000 nucleotides long. The genome has a guanine + cytosine content of 39 %. The genome sequence has termini with hairpin structure. The genome has terminally redundant sequences. The terminally redundant sequences have reiterated inverted terminal sequences which are tandemly repeated; are reiterated internally as direct repeats in tandem form. Double-stranded DNA is covalently. Double-stranded DNA is linked at both ends. Proteins The viral genome encodes structural proteins and non-structural proteins. Lipids Lipids are present and located in the envelope. Viral membranes include glycolipids. Genome Organization and Replication Release: The virus envelope is acquired from the host cell during the maturation process. Envelope lipids are derived from the host cell plasma membrane.