Contains about a dozen major host-specific pathogens. Most of these viruses are not human viruses. However two recently discovered are causative agents of the common cold. So names because of the large peplomers projecting from the envelope.
Virion is pleomorphic, coronavirus often being disk, kidney shape or even rod like.
This acts like the matrix protein. And carries binding, membrane fusion and hemagglutinating activity. RNA is single stranded positive polarity of about 30 kb, which is 5' capped and 3' poly A. Viral replication. The infectious plus strand is translated directly, the product of the 5' two thirds of the genome being two polyproteins, the larger of which is produced by ribosomal frame shifting. Draw out Fig 27-2 or figure from Weber.