Fig. 2.

IP₅ 2-K active site. AMPPNP (A) and IP₅ (B) interactions as found in the ternary substrates complex. Residues involved in AMPPNP or inositide recognition are shown in sticks. Water molecules are represented in white and hydrogen bonds as dashed lines. (C) L3 atomic interactions as observed in the ternary products complex. This loop interacts with the side chain of Arg130 and Trp129 from α6, and residues in or near L2 as Gln237 and Arg241. L3 keeps together regions involved in inositide recognition. (D) Substrates (Left) and products (Right) recognition and metal interactions in both ternary complexes. The substrates complex shows only one metal, Mg1, bound to the L5 residues Asp407 and Ser409, whereas the products complex shows two metals, Mg1 and Mg2, both bound to Asp407 and bridging inositide and nucleotide ligands.