FIGURE 2.

Identification of the PS-binding site of the PDK1 PH domain. A, the crystal structure of PDK1-PH complexed with inositol 1,3,4,5-tetrakisphsphate (IP₄) and glycerol (Protein Data Bank code 1W1D) (37). The PDK1-PH structure is shown in a ribbon representation with the Connolly molecular surface. IP₄ and glycerol are shown in space-filling representations. PtdIns(3,4,5)P₃ and PS-binding residues are shown in stick representations and labeled. The molecule is orientated with its top part facing the membrane. B, a model structure of a PDK1-PH-IP₄-PS complex. The PDK1-PH molecule is shown in a surface representation in the same orientation as in Fig. 1A. Red and blue colors qualitatively indicate negative and positive potentials, respectively. IP₄ and PS molecules are shown in space-filling representations.