FIGURE 5.

Ala insertions in the Sgf11 helix disrupt binding to Sus1. A, helical nets show the hydrophobic stripe on Sgf11 to which Sus1 binds. B, shown is an illustration of how the stripe is disrupted by insertion of an Ala after residue 18. C, binding assays demonstrate the reduced affinity of Sus1 for Sgf11 Ala variants. GST control (lane 2); GST-Sgf11 wild-type (lane 3), I15A (Ala substitution for Ile15, lane 4), 19A (Ala inserted after residue 18, lane 5), and 20A (Ala inserted after residue 19, lane 6) were coexpressed with full-length Sus1 and affinity purified from cell lysates. Proteins were visualized by SDS-PAGE.