FIG. 2.

Presentation of the fusion peptide and mutations of HaF. (A) Helical-wheel presentation of the fusion peptide of HaF. Fusion peptide residues are numbered from the N terminus of the F₁ subunit. The mutations are indicated at the outside of the helical wheel with arrows and substituted amino acids. (B) Linear presentation of the fusion peptide of HaF (the first 18 N-terminal amino acids of the cleaved HearNPV F₁ fragment). The open arrow indicates the furin cleavage site. Solid arrows indicate amino acid changes for the mutations.