“…The S glycoprotein possesses an N-terminal signal sequence, which is cleaved during intracellular processing, and thus is absent from the mature S protein (Abraham et al, 1991 ;Boireau et al, 1990 ;Parker et al, 1990a, b). The S protein is synthesized as a high-molecular-mass precursor, which, after glycosylation, undergoes proteolytic cleavage, a host-celldependent event, to yield two subunits of molecular mass 85-100 kDa corresponding to the N-terminal S1 and the C-terminal S2 glycopolypeptides (Boireau et al, 1990 ;Parker et al, 1990a, b). Deduced amino acid sequences of BCoV and HCoV-OC43 revealed as much as 95, 91, 94 and 96 % identities between their HE, S, M and N proteins, respectively (Mounir & Talbot, 1992, 1993a.…”