Notes on Genus: Mamastrovirus

icosahedra

Type member: Human astrovirus

Contents

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

General Description

This is the one of two genera in the family Astroviridae. It consists of viruses that infect mammals some of whose virions have a star-shaped appearance (Greek astron = star).

Morphology

Virions isometric (icosahedral), not enveloped, 28-30 nm in diameter, 10% of which have a distinctive 5- or 6-pointed star shape.

Genome

Monopartite positive sense single-stranded RNA 6.8-7.9 kb in length with a 3'-polyA tail.

Genus Genomic Organization

The non-structural proteins are encoded by two ORFs that are expressed as one by ribosomal frameshift. The coat protein precursor is towards the 3'-end of the genome and is translated from a subgenomic RNA.

Type Member Genomic Organization

The genome of about 6,800 nucleotides has three open reading frames: