Phosphodiesterase (PDE) that catalyzes the hydrolysis of cyclic diguanylate (c-di-GMP) to GMP (PubMed:19170727, PubMed:24066157). Hydrolyzes c-di-GMP to GMP in a two-step reaction, via the linear intermediate 5'-phosphoguanylyl(3'->5')guanosine (pGpG). In vitro, can use pGpG as an alternative substrate and hydrolyze it into GMP (PubMed:24066157). Acts in regulation of motility, synthesis of virulence determinants and biofilm architecture (PubMed:19170727). cyclic di-3',5'-guanylate + 2 H2O = 2 GMP + 2 H(+) Activated by Mg(2+) and Mn(2+). kcat is 0.00015 sec(-1). Optimum pH is 8. Optimum temperature is 30 degrees Celsius. Monomer. Disruption mutant has increased levels of cyclic di-GMP. Mutation leads to reduction in both swarming and twitching motility, to a decrease in pyocyanine production, to a reduction in the extracellular levels of the ExoS effector, and a reduction in virulence. It produces a flatter biofilm.