Coronaviridae1

Siddell, S.G.; Anderson, R.; Cavanagh, D.; Fujiwara, K.; Klenk, H.D.; Macnaughton, M.R.; Pensaert, M.; Stohlman, S.A.; Sturman, L.; van der Zeijst, B.A.M.

The family Coronavirtdae comprises a monogeneric group of 11 viruses which infect vertebrates. The main characteristics of the member viruses are: (i) Morphological: Enveloped pleomorphic particles typically 100 nm in diameter (range 60-220 nm), bearing about 20 nm long club-shaped surface projections, (ii) Structural: A single-stranded infectious molecule of genomic RNA of about (5-7) × 10(6) molecular weight. A phosphorylated nucleocapsid protein [mol.wt. (50-60) × 10(3)] complexed with the genome as a helical ribonucleoprotein; a surface (peplomer) protein, associated with one or two glycosylated polypeptides [mol.wt. (90-180) × 10(3)]; a transmembrane (matrix) protein, associated with one polypeptide which may be glycosylated to different degrees [mol.wt. (20-35) × 10(3)]. (iii) Replicative: Production in infected cells of multiple 3′ coterminal sub genomic mRNAs extending for different lengths in the 5′ direction. Virions bud intracytoplasmically. (iv) Antigenic: 3 major antigens, each corresponding to one class of virion protein, (v) Biological: Predominantly restricted to infection of natural vertebrate hosts by horizontal transmission via the fecal/oral route. Responsible mainly for respiratory and gastrointestinal disorders.