Figure 4

Structural modeling of Tcur1278 and Tcur0390 polyester hydrolases. Homology modeling was performed with the Phyre2 web server (Kelley and Sternberg [2009]). The catalytic triad of (A) Tcur1278 and (B) Tcur0390 is formed by S130, D176 and H208. The 2PET model substrate was docked using GOLD 5.1 with its central ester bond constrained between 2.7 and 3.1 Å in the oxyanion hole formed by the main chain NH groups of F62 and M131 (broken yellow lines). The hydrogen bonds stabilizing the tetrahedral intermediate formed during the catalytic reaction are shown as broken lines in blue. The backbone structures are shown as gray cartoons. The electrostatic surface properties of Tcur1278 (C) and Tcur0390 (D) are shown with negatively charged residues in red, positively charged residues in blue and neutral residues in white/gray, respectively. The lipophilic surface properties of Tcur1278 (E) and Tcur0390 (F) are shown with hydrophilic residues in pink and hydrophobic residues in bright green, respectively. The docked 2PET model substrate is shown in cyan.