Part of a signaling cascade that regulates curli biosynthesis. The cascade is composed of two cyclic-di-GMP (c-di-GMP) control modules, in which c-di-GMP controlled by the DgcE/PdeH pair (module I) regulates the activity of the DgcM/PdeR pair (module II), which in turn regulates activity of the transcription factor MlrA and expression of the master biofilm regulator csgD. 2 GTP = cyclic di-3',5'-guanylate + 2 diphosphate Binds 1 Mg(2+) ion per monomer. Purine metabolism; 3',5'-cyclic di-GMP biosynthesis.