Notes on Genus: Betanodavirus

icosahedra

Type member: Striped jack nervous necrosis virus

Contents

• Members of this Genus
• General Description
• Morphology
• Electron Micrograph
• Genome
• Genus Genomic Organization
• Genome Map
• Type Member Genomic Organization
• All Known Sequences
• Curated Sequences

General Description

This is one of two genera in the family Nodaviridae and consists of those viruses that infect fish.

Morphology

Virions isometric (icosahedral), not enveloped, 25-30 nm in diameter without any distinctive surface struture. Empty particles are sometimes seen in virus preparations.

Genome

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.