Figure 8.

Suc gradient flotation reveals that the PH-like domain of SUS1 influences binding to plant microsomes. Equal amounts (0.30 pmol μL⁻¹) of wild-type SUS1 or the Ala-substituted mutants listed above the sections were mixed with equal amounts of apical leaf microsomes at pH 7.5 and 150 mm Suc. After pelleting the microsomes and removing aliquots of the supernatants (input) the pellets were subjected to Suc gradient flotation and the top fraction probed on immunoblots (IB) with an antibody against SUS1 (anti-SUS-PH). A representative immunoblot is shown and densitometry of three separate blots is displayed in the graph at the bottom. Y axis bars indicate ses.