Structure and comparison of A. thaliana IPMK.
A, stereo schematic of secondary structure. B, representative stereo density of core of A. thaliana IPMK and anomalous peaks. Single coefficient-weighted density (calculated by FFT in CCP4 4. 6.1) is shown at 1.5σ (blue), and anomalous density is shown at 12σ around three of the five seleno-methionine residues used to solve the structure. C, stereo overlay of A. thaliana IPMK (blue), S. cerevisiae IPMK (green), and H. sapiens IP3K (yellow) structures. D, active site comparison of A. thaliana IPMK and H. sapiens IP3K with Ins(1,4,5)P3. Stereo view of the active sites of A. thaliana IPMK and H. sapiens IP3K with AMP-PnP from H. sapiens IP3K and Ins(1,4,5)P3 modeled in the proposed 6-kinase orientation. Note the poor structural conservation on the opposite side of the inositol ring and much more extensive structure and contacts of H. sapiens IP3K.