FIG 3.

Ribbon diagram of the GGDEF domain of PleD binding the substrate analog GTPαS (PDB code 2V0N). (A) Amino acids interacting with the substrate analog GTPαS (including Lys442 and Arg446, interacting with the phosphate group) and the Mg²⁺ ions (Asp327 and Glu370) (1, 6, 15) are indicated. Mg²⁺ ions are in green. (B) Amino acid motifs providing additional functionality to GGDEF domains. R359XXD362 is the core motif of the I-site. The XXD327XD329 motif was demonstrated to have a role in protein-protein interactions in GGDEF domain proteins others than PleD.