Sequence and structure of the coronavirus peplomer protein.

Coronaviruses display a characteristic fringe of large (17–20 nm), clubshaped peplomers, each consisting of a di- or trimer of the peplomer protein (Cavanagh et al. 1983). The peplomer protein, E2, plays an important role during the infection proces. It mediates the binding of virions to the host-cell receptors and is involved in membrane fusion. In addition, the E2 protein appears to be a major inducer of protective immunity to coronaviral infection (reviewed by Sturman and Holmes, 1983)