Figure 2: The Ska complex binds MTs through multiple positively charged clusters.
From: Structural basis for microtubule recognition by the human kinetochore Ska complex
(a) Cartoon representation of the Ska1–MTBD where surface-exposed K/R residues are shown as sticks (left). Surface representation of the Ska1–MTBD in the same orientation with electrostatic surface potential revealing the presence of positively charged patches (right). Residues clustered based on their proximity and mutated to A to test their involvement in MT recognition are highlighted in different colours. (b) Cosedimentation assays of the different K/R- to A-untagged Ska mutants were performed. Representative gels (upper panel) and quantifications of MT cosedimentation assays (bottom panel). Concentration of Ska1 mutants and MTs used in the assays are 3 μM and 6 μM, respectively (mean±s.d., n
3, *P
0.05, ***P0.001; t-test; right bottom panel). Kd values were calculated using 1 μM Ska and 0–12 μM MTs (bottom left panel). Uncropped scans of the gels are shown in Supplementary Fig. S8b.
