Figure 4

Identification of Sre1-binding surface based on the Scp1-WD40 structure. (A) The top surface of the Scp1-WD40 propeller. The left and right panels depict the electrostatic surface potential and the corresponding cartoon representations, respectively. Six basic residues from blades 1 and 2 constitute a positively charged surface patch, the “RK patch”. (B) A close-up view on the residues involved in Sre1 binding. Six basic residues, one acidic residue and two Ser residues are colored blue, red and yellow, respectively. (C) Interaction between Scp1-WD40 variants and Sre1 regulatory domain assessed by MBP-mediated pull-down assay. The WT (residues 567-1 085) and Scp1-Δ24 were included as control. Scp1-M1/M2/M3 almost completely lost association with Sre1 (Lanes 10-12, boxed in red). Scp1-M4/M5/M6 showed decreased binding with Sre1 (Lanes 13-15, boxed in green). The experiments were performed with the same protocol as that for Figure 1B.