(A) ScNaa10 (yellow), ScNaa15(cyan), and ScNaa50 (violet) are shown in cartoon. The N-terminal two alpha helices (residues 1–53) of Naa15 are not resolved and not shown in the structure. Several alpha helices of Naa15 that contribute to Naa10 and Naa50 binding are labeled.
(B) Zoom-in view of the interface between Naa50, Naa10 and Naa15. Residues that contribute to interactions between Naa10 and Naa50 are shown.
(C) Zoom-in view showing key residues involved in interactions with IP6.
(D) Representative isothermal titration calorimetry (ITC) of curve of IP6 titrated into SpNatA with the calculated dissociation constant indicated.