Fig. 4: HURP interacts with the longitudinal surface of β-tubulin by a three-α-helix bundle.
From: HURP binding to the vinca domain of β-tubulin accounts for cancer drug resistance
a A cryo-EM map of the HURP (428-534)•β-tubulin•α-tubulin complex. The map is segmented into HURP (428-534) (Green), β-tubulin (light gray) and α-tubulin (dark gray) (EMD-38181). b Cartoon representation of the HURP (428-534)•β-tubulin•α-tubulin structure. HURP (428-534), β-tubulin and α-tubulin are shown in green, dark blue and light blue, respectively. The secondary structures of β-tubulin that contribute to the HURP interaction are colored differently. (PDB ID: 8X9P) c A zoomed-in view of the HURP (428-534)•β-tubulin•α-tubulin complex highlighted by the black dashed box in b is shown. The α-helix H, a loop between α-helix G and β-strand E, and the α-helix N of β-tubulin that mediate the HURP interaction are highlighted in pink, red and orange, respectively. d A schematic representation of the interaction between the HURP (428-534) and β-tubulin using the same color code as shown in a. Yellow boxes highlight two binding patches. e A close up view showing the interaction between the HURP (428-534) and β-tubulin. The HURP (428-534) and β-tubulin are shown as cartoon representations with the same color code in c. Key residues involved in the binding are indicated and shown as sticks. f SEC (Superdex 200) elution profiles (arb. units) for the GST-HURP (430-550) WT•tubulin complex (black line), GST-HURP (430-550) (light gray), and tubulin (dark gray). The void volume (Vo) is indicated. g The peak fractions of the GST-HURP (430-550) WT•tubulin complex (Top panel), GST-HURP (430-550) (Middle panel), and tubulin (Low panel) in f were analyzed by SDS-PAGE and stained with Coomassie blue. Representative gels are shown (n = 3). h–j SEC (Superdex 200) elution profiles (arb. units) for (h) GST-HURP (430-550) patch 1 mutant, (i) GST-HURP (430-550) patch 2 mutant or (j) GST-HURP (430-550) patch 1&2 mutant in the presence of tubulin (Black lines). Tubulin alone profiles are shown as light gray lines. The void volume (Vo) is indicated.
