Examples: histone, BN000065

Project: PRJNA16850

Description of Corticoviridae

adapted from ICTVdb

Virion Properties

Morphology

Phages consist of a capsid and an internal lipid membrane. Virus capsid is not enveloped. Internal lipid membrane located between outer and inner protein shell. Capsid/nucleocapsid is round and exhibits icosahedral symmetry (T=12), or 13). The capsid is isometric and has a diameter of 60 nm (or more). The capsid shells of virions are composed of three layers. Capsids appear hexagonal in outline. The capsid surface structure reveals a regular pattern with distinctive features. The capsomer arrangement is clearly visible. Surface projections are distinct, brush-like spikes protruding from the 12 vertices.

Physicochemical and Physical Properties

Virions have a buoyant density in CsCl of 1.29 g cm-3.

Nucleic Acid

The Mr of the genome constitutes 13% of the virion by weight. The genome is not segmented and contains a single molecule of circular; supercoiled, double-stranded DNA. The complete genome is 9000-10000 nucleotides long. The genome has a guanine + cytosine content of 43 %.

Proteins

The viral genome encodes structural proteins and non-structural proteins.

Lipids

Lipids are present and located in the internal component (between the outer and inner shell). Virions are composed of 13% lipids by weight. The composition of viral lipids and host cell membranes are distinctly different. Lipids in the viral membrane have a bilayer structure. Viral membranes include phosphatidyl glycerol and phosphatidyl ethanolamine.

General