Notes on Genus: Sirevirus

variable ovoid or spheroid

Type member: Glycine max SIRE1 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 the genera (distinct phylogenetic lineages) in the retroelement family Pseudoviridae. The name is derived from the type member, Glycine max SIRE-1 virus.

Morphology

Virus-like particles (VLPs) are poorly studied but seem to be non-enveloped, ovoid or spheroid in shape and 60-80 nm in diameter.

Genome

The major molecule is a positive sense ssRNA transcript of 4.5-10.5 kb flanked by Long Terminal Repeats (LTRs).

Genus Genomic Organization

Genome organisation is variable with from 1 to 3 ORFs encoding the gag, pol and (sometimes) env proteins. Second and third ORFs (where present) are in separate reading frames and are probably translated by ribosomal frameshift.. As in other genera of the family, the pol contains protease (PR), integrase (IN) and reverse transcriptase (RT) domains in that order.

Type Member Genomic Organization

There is a single gag-pol ORF of 177 kDa. The sequence may be incomplete with an env protein expressed by ribosomal frameshift at the C-terminus of the gag-pol.