Fig. 6.

(a) SDS-PAGE and N-terminal sequencing analyses of DKNV virion proteins. *The determined N-terminal aa sequences of p80 and p55 are shown in arrowhead-shaped boxes. **The N terminus of p30 could not be directly sequenced because of the presence of a blocked N-terminal residue. (b) Cleavage sites in the precursor ORF2a polypeptide. An arrow and an arrowhead represent the cleavage sites of signal peptidase and furin-like proteases, respectively. (c) Predicted topology of the two forms of DKNV spike glycoprotein, msS1 and msS2. Cylinders and solid lines represent predicted transmembrane domains and ectodomains, respectively. The precursor ORF2a polypeptide is posttranslationally processed by signal peptidase to yield msS1 and further processed by a furin-like protease to yield msS2