Notes on Family: Paramyxoviridae

enveloped spheres

Contents

Members of this Family
General Description
Morphology
Genome
Genera in the Family
All Known Sequences
Curated Sequences

General Description

This family is characterised by its (usually) spherical, enveloped, particles at least 150nm in diameter, which contain a monopartite negative sense ssRNA genome of 15-18kb. It is classified in the order Mononegavirales with three other families of enveloped viruses with monopartite negative sense genomes, i.e. the Filoviridae (particles usually filamentous), Bornaviridae (particles about 90 nm diameter) and Rhabdoviridae (particles bullet-shaped).

Morphology

Virions pleomorphic but usually spherical, enveloped, 150 nm in diameter or larger with spike-like projections.

Genome

Monopartite single-stranded negative sense RNA of 15-18 kb. There is no genome-linked protein (VPg) at the 5'-terminus nor a 3'-polyA tail. There are 6-10 transcriptional elements with the RNA polymerase at the 5'-end of the genome and the capsid nucleoprotein at or near the 3'-end. There is a fairly standard order of the major mRNAs (here listed in their order on the template strand - i.e. from 3' to 5' with respect to the virion strand):

Genera in the Family

Classification is based on genome organisation and size and on the relatedness of the encoded proteins. Host type is sometimes also significant.