Fig. 1.

a Canonical organization of the coronavirus genome. Major genes present in all coronaviruses, from 5′ to 3′, encode the replicase/transcriptase complex, the spike (S) protein, the envelope (E) protein, the membrane (M) protein, and the nucleocapsid protein (N). In some variants, a fifth major protein, the hemagglutinin-esterase (HE), is represented proximal to the spike protein. b Organization of the coronavirus virion. S, E, and M proteins are embedded in the membrane envelope, whereas the N protein encases the viral genome