Notes on Genus: Pseudovirus

variable ovoid or spheroid

Type member: Saccharomyces cerevisiae Ty1 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. DNA synthesis is primed by a complete t-RNA molecule. The name reflects uncertainty as to whether to regard these elements as viruses.

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 4.5-12 kb flanked by Long Terminal Repeats (LTRs).

Genus Genomic Organization

The two major genes gag and pol are produced from 2 ORFs 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

The two major genes are

1. gag: structural polyprotein of 49 kDa
2. pol: polymerase of c. 150 kDa consisting of the protease (PR), integrase (IN) and reverse transcriptase (RT)