Luteoviridae. Luteoviridae

Description of Luteoviridae adapted from ICTVdb Virion Properties Morphology Virions consist of a capsid. Virus capsid is not enveloped, round with icosahedral symmetry. The isometric capsid has a diameter of 25-30 nm. Capsids appear round, or hexagonal in outline. The capsomer arrangement is clearly visible, or is not obvious. The capsid consists of 32 capsomers. Electron microscopic preparation and references: Virus preparation contains few virions. Physicochemical and Physical Properties Virions have a buoyant density in CsCl of 1.38-1.42 g cm-3. Nucleic Acid The Mr of the genome constitutes 28-37% of the virion by weight. The genome is not segmented and contains a single molecule of linear positive-sense, single-stranded RNA. Minor species of non-genomic nucleic acid are also found in virions. The encapsidated nucleic acid is mainly of genomic origin, but virions may also contain satellite RNA. The genome is sequenced, and complete sequence is about 5600-6044-6900 nucleotides long. The 5'-end of the genome has a genome-linked protein (VPg). Proteins Proteins constitute about 70-72% of the particle weight. The viral genome encodes structural proteins and non-structural proteins. Virions consist of 1 structural protein(s), or 2 structural protein(s), or 4 structural protein(s). Non-Structural Proteins: Virus-coded non-structural proteins have been isolated, or identified by sequence analysis and 3 non-structural protein(s) are found, or 6 non-structural protein(s) are found. Lipids Lipids are absent. Genome Organization and Replication By itself, genomic nucleic acid is infectious. Translation: The genome replicates in the cytoplasm.