Figure 2. Structure of the Stu2 C-terminal segment (CTS) bound to the Ndc80c^dwarf.

(A) Stu2 CTS (residues 855–888) bound to the Ndc80c^dwarf. The peptide binds at the four-way junction of Ndc80, Nuf2, Spc24, and Spc25 in a groove between Ndc80 and Spc24. (B) Model of the Stu2 peptide built into the 2Fo-Fc map (gray mesh); anomalous difference map (green mesh), contoured at 8σ, showing the position of SeMet in the peptide. (C) Conservation of residues at the contacts of Stu2 CTS, Ncd80, and Spc24, shaded from red (conserved) to blue (variable). Nuf2 and Spc25 are in gray. Ndc80c components in surface representation; Su2 in stick representation. The N- and C-termini of the Stu2 peptide are indicated. The expanded region depicted in (D) is shown as a black box. (D) Expanded view of the Ndc80-Spc24 surface corresponding to the boxed region in panel C, showing conserved pockets for the three hydrophobic residues of Stu2 discussed in the text. Coloring as in (C). (E and F) Detailed views of the contacts between the Stu2 peptide and Ndc80 and Spc24.