Notes on Genus: Respirovirus

enveloped spheres

Type member: Sendai virus

General Description

The genus Respirovirus is one of nine genera in the family Paramyxoviridae and contains viruses that produce a non-strutural protein C, a hemagglutinin-neuraminidase attachment protein and translate protein V from an edited RNA transcript. It is named after the Latin respirare = to breathe.

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 about 15 kb. There is no genome-linked protein (VPg) at the 5'-terminus nor a 3'-polyA tail.

Genus Genomic Organization

There are 6 transcriptional elements (mRNA species). Their major ORFs are listed here in their order on the template strand - i.e. from 3' to 5' with respect to the virion strand:

1	N	57-58 kDa	Coat protein (nucleocapsid)
2	P	63-67 kDa	Phosphoprotein
3	C	24-26 kDa	Non-structural protein from same mRNA transcript as P but in a different reading frame; some isolates may also produce a shorter Y1 (21 kDa) protein
4	V	24 kDa	Produced from the P transcript by RNA editing in some viruses: shares the N-terminus of P but then has a frame shift
5	M	38-40 kDa	Matrix protein
6	F	60-61 kDa	Fusion protein: glycosylated envelope protein
7	HN	63-65 kDa	Hemagglutinin-neuraminidase attachment protein
8	L	253-259 kDa	Polymerase

Type Member Genomic Organization