Description of Tetraviridae
adapted from
ICTVdb
Virion Properties
Morphology
Virions consist of a
capsid. Virus capsid is not enveloped, round with
quasi-
icosahedral symmetry (T=4). The capsid is isometric and has a
diameter of 40 nm. Capsids appear hexagonal in outline. The
capsid surface structure reveals a regular pattern with
distinctive features (that are resolved by cryo-electron
microscopy and image reconstruction). The capsomer arrangement is
clearly visible in cryo-electron microscopy.
Physicochemical and Physical Properties
Virions have a buoyant density in
CsCl of 1.28-1.3 g cm
-3.
Nucleic Acid
The Mr of the genome constitutes 11% of the virion
by weight. The genome is not segmented and contains a single
molecule of, or segmented and consists of two segments of linear,
positive-sense, single-stranded RNA. The complete genome is
5500-8000 nucleotides long, is sequenced, complete sequence is
about 5500 nucleotides long, is sequenced, but only an estimate
is available, complete sequence is 2500 nucleotides long.
Proteins
The viral genome encodes structural
proteins.
Lipids
Lipids are undetermined (however the
amino terminus of the coat protein precursor, alpha, is blocked
by an unidentified entity).
Carbohydrates
Carbohydrates have not been reported.