Figure 3.

Water molecules at both sides of the nucleophilic elbow of PhaC_Cs-CAT. (a) A cluster of water molecules (red balls with dotted surfaces) is located at the active site cavity around the nucleophilic elbow. The cavity is covered by the LID region of the CAP subdomain (magenta). Other water molecules are shown as red crosses. Color codes are the same as in Fig. 2. The hydrogen bond between Glu329 and Arg365 is indicated by a broken line. (b) As in a, but without the LID region. Hydrogen bonds involving the catalytic residues are shown as broken lines. Water molecules are divided into two groups, one group at Site A and the other at Site B. The cavity is mostly hydrophobic although Tyr412 and His324 are located at Site A and Asn220 at Site B. Hydrogen bonds are indicated by broken lines.