FIG. 1.

Predicted geometries of disulfide bonds introduced into the prefusion MV F trimer. Homology models of MV F were generated on the basis of the coordinates reported for prefusion PIV5 F and are colored by monomer subunits. (A, B, and C) A disulfide bond between residues 452 and 460 is predicted to establish an intersubunit link between the top of the HR-B prefusion stalk and the base of the globular head domain. Side view of the trimer (A), view from the dotted line in panel A up the HR-B stalk (B), and close-up view of the intersection of stalk and head domain (C). Cysteine side chains of engineered bonds are highlighted in blue; individual sulfur atoms are shown in orange. (D, E, and F) A disulfide bond between residues 307 and 448 is predicted to link two loops in the base of the prefusion head domain of the same monomer. Individual views and coloring of engineered bonds as described for panels A through C.