Phosphodiesterase (PDE) that catalyzes the hydrolysis of 3'3'-cyclic GMP-AMP (3'3'-cGAMP), leading to linear 5'-pApG (PubMed:25837739, PubMed:30365951). Also displays 5'-nucleotidase activity, further hydrolyzing 5'-pApG to 5'-ApG. Counteracts the function of the 3'3'-cGAMP synthase DncV, and is involved in the modulation of intracellular 3'3'-cGAMP levels. Enhances bacterial chemotaxis and inhibits intestinal colonization in vivo. Thus exerts a crucial role in regulating bacterial infectivity through catalyzing 3'3'-cGAMP degradation. Is specific for 3'3'-cGAMP since it cannot degrade other cGAMP linkage isomers (3'2'-, 2'3'-, and 2'2'-cGAMPs) (PubMed:25837739). Is also able to hydrolyze c-di-GMP but not c-di-AMP (PubMed:25343965, PubMed:25837739). 3',3'-cGAMP + H2O = 5'-pApG-3' + H(+) 5'-pApG-3' + H2O = 5'-ApG-3' + phosphate Requires a divalent metal cation for activity. Likely has a bi-nuclear metal center. Has the highest enzyme activity with Ca(2+), followed by Mg(2+). Optimum pH is 8.5-10.5. Monomer. Expression is up-regulated by 3'3'-cGAMP production (at both mRNA and protein levels) (PubMed:25837739). Transcripts are more abundant in biofilm cells than in planktonic cells (PubMed:25343965). Significant increase in the ability to colonize the small intestine compared to the wild-type strain. No defect in biofilm formation. Enforced DncV expression in mutant cells lacking this gene causes an enhanced inhibition of chemotaxis. The double mutants lacking both VC_A0681 and VC_A0210 or both VC_A0681 and VC_A0931 show enhanced bacterial infectivity, and the triple one (VC_A0681, VC_A0210 and VC_A0931) has the highest infectivity, which demonstrates that V-cGAPs play non-redundant roles in cGAMP degradation.