Plays a central, regulatory role in the late adaptive responses and affects the levels of many genes (PubMed:24163345). May act via regulation of cAMP levels (PubMed:26904951). Decreases the expression of motility genes and induces genes involved in biofilm formation, by controlling the expression of SlrR (PubMed:21856853). Required for formation of intercellular nanotubes that bridge neighboring cells to allow molecular exchange (PubMed:26906740). Plays a key role in directing the early stages of colony development (PubMed:26904951). In vitro, has a metal-dependent phosphodiesterase activity against 2',3'-cAMP and 2',3'-cGMP. Has also 3',5'-cyclic-nucleotide phosphodiesterase activity, but cannot use cyclic di-AMP or cyclic di-GMP, and does not have phosphatase activity (PubMed:24163345). a nucleoside 2',3'-cyclic phosphate + H2O = a nucleoside 3'-phosphate + H(+) Corresponds to iron 2 in the structure. Corresponds to iron 1 in the structure. kcat is 15.0 min(-1) with 2',3'-cAMP as substrate. kcat is 22.1 min(-1) with 2',3'-cGMP as substrate. kcat is 9.2 min(-1) with 3',5'-cAMP as substrate. kcat is 7.7 min(-1) with 3',5'-cGMP as substrate. Homodimer. Localizes to the cytoplasm, cell periphery and nanotubes. Deletion of the gene affects the levels of over 800 mRNAs (PubMed:24163345). Deletion mutant overexpresses flagellin and other genes of the sigma-D-dependent motility regulon. In contrast, the two major operons for biofilm formation are not expressed and the mutant is unable to form biofilms. All cells are short and motile (PubMed:21856853). Deletion also results in a significant decrease in intercellular molecular exchange (PubMed:26906740). Mutant displays aberrant developmental patterns and forms smaller colonies (PubMed:26904951). Belongs to the YmdB-like family.