Structure of the C-terminal IP target peptide binding to PDZ1.

<p><b>A</b>: Ribbon diagram showing the three dimensional structure of PDZ1 (residues 7–86, green with gray carboxylate-binding loop) and the bound C-terminus of IP (⁻⁶IAACSLC⁰, yellow) from an adjacent molecule in the asymmetric unit. Six β-strands (β1-β6), two α-helices (α1–α2) and carboxylate-binding loop (dark gray) are indicated. Vector derived residues have been omitted for clarity. <b>B</b>: Two-dimensional representation of interactions between PDZ1 (green) and the C-terminal IP target peptide (yellow). Hydrogen bonds are shown as dashed lines and hydrophobic interactions as arcs with radial spokes. This figure was generated using LIGPLOT <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0053819#pone.0053819-Wallace1" target="_blank">[48]</a>. <b>C</b>: Stereo representation of the ligand-binding groove of PDZ1 (green) and the IP target peptide (yellow). Oxygen, nitrogen and waters molecules are shown in red, dark blue and cyan, respectively. Sulfur atoms are colored in yellow. Hydrogen bonds are shown as dashed lines. The orientation is similar to that in panel A.