Potyviridae. Potyviridae

Description of Potyviridae adapted from ICTVdb Virion Properties Morphology Virions consist of a capsid. Virus capsid is not enveloped. Capsid/nucleocapsid is elongated with helical symmetry. Virus preparations contain one particle component, or more than one particle component. The capsid is filamentous, flexuous; with a clear modal length, or clear predominate lengths with a length of 680-900 nm, or 500-600 nm; 200-300 nm and a width of 12-15 nm. Pitch of helix is 3.4 nm. Physicochemical and Physical Properties Virions have a buoyant density in CsCl of 1.26-1.34 g cm-3. Nucleic Acid The Mr of the genome constitutes 5% of the virion by weight. The genome is linear, positive-sense, single-stranded RNA. The complete genome is 8500-10000 nucleotides long. The 5'-end of the genome has a genome-linked protein (VPg). The 3'-terminus has a poly (A) tract. The multipartite genome is divided among more than one type of particle and the segments are distributed between 2 different types of particles. Proteins Proteins constitute about 95% of the particle weight. The viral genome encodes structural proteins and non-structural proteins. Lipids Lipids are not reported.