Membrane glycoprotein (M, responsible for transmembrane transport of nutrients, budding release of newborn virus and formation of virus envelope). A few species also have hemagglutinin glycoprotein (HE protein, hemagglutinin-esterase).
The nucleic acid of coronavirus is non-segmented single-stranded (+)RNA with a length of 27-3 1kb. It is the longest RNA nucleic acid chain in RNA virus, which has a unique and important structural feature of positive-strand RNA: there is a methylated "hat" at the 5' end of RNA chain.
Morphological structure:
Coronavirus particles are irregular in shape and about 60-220nm in diameter. Virus particles are wrapped by a layer of fat membrane, and there are three kinds of glycoproteins on the surface of the membrane: spike glycoprotein (S, the receptor binding site, cell lysis and major antigen site); Small envelope glycoprotein (E, envelope protein).