Notes on Genus: Betanodavirus
Type member: Striped jack nervous necrosis virus
This is one of two genera in the family Nodaviridae
and consists of those viruses that infect fish.
Virions isometric (icosahedral), not enveloped, 25-30 nm in diameter without any distinctive surface struture. Empty particles are sometimes seen in virus preparations.
Bipartite positive sense single-stranded RNA without 3'-polyA tails of approximate lengths 3.1 (RNA1) and 1.4kb (RNA2).
Genus Genomic Organization
RNA1 has one large ORF encoding an RNA polymerase (protein A) and one smaller protein (B2). RNA2 has a single ORF, a coat protein precursor (protein alpha), which is subsequently cleaved into two products (beta and gamma).
Type Member Genomic Organization
RNA1 (3107 nts) encodes two proteins:
- Polymerase protein A (111 kDa)
- Protein B2 (8 kDa) of unknown function
RNA2 (1421 nts) encodes the coat protein precursor alpha (37 kDa) which is subsequently cleaved into the two products.