Fig. 3. Binding of 5-PA-InsP5 (2) to human PPIP5K2KD (a–c) and phosphorylation of 2 by PPIP5K2KD (d). (a) 5-PA-InsP5 (2, ball-and-stick model) and its interacting residues (stick model) for hPPIP5K2 are shown in light blue for carbon, blue for nitrogen, orange and red for phosphate groups. Residues that make contacts with 5-PP-InsP5 (green stick) are also shown in green carbon. Magnesium atoms are shown as spheres. C-4 and C-5 in the inositol ring are labelled. (b) Residues that interact with PA or PP are shown. Bond distances (dashed lines) are denoted in Å. (c) Key catalytic residues are shown in stick model. Inositol phosphates and nucleotide cofactors are shown in ball-and-stick model. Colours are as (a). Also shown are catalytic magnesium atoms (magenta spheres). C-1 of the inositol ring is labelled. Bond distances (dashed lines) are denoted in Å. (d) Phosphorylation of 5-PA-InsP5 by PPIP5K2KD.
