"Specific enzymatic cleavages in vivo yield mature proteins. The precursor is processed into S1 and S2 by host cell furin or furin-like protease to yield the mature S1 and S2 proteins. The cleavage site between S1 and S2 requires the optimal sequence [KR]-X-[KR]-R. Additionally, a second cleavage leads to the release of a fusion peptide after viral attachment to host cell receptor."xsd:string
SPARQL endpoint