Phosphodiesterase (PDE) that catalyzes the hydrolysis of 3'3'-cyclic GMP-AMP (3'3'-cGAMP), leading to linear 5'-pApG (PubMed:25837739, PubMed:30365951). 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); is also able to hydrolyze c-di-GMP but not c-di-AMP (PubMed:25837739). 3',3'-cGAMP + H2O = 5'-pApG-3' + H(+) Requires a divalent metal cation for activity. Likely has a bi-nuclear metal center. Has the highest enzyme activity with Mn(2+), and when incubated with Ni(2+), its activity is about 60% lower than that observed with Mn(2+). Optimum pH is 10.0. Monomer. Expression is up-regulated by 3'3'-cGAMP production (at both mRNA and protein levels). Consists of two tandem domains of about 15% identity and similar three-dimensional topology that interact to form a pseudo-dimeric structure. The N-terminal domain (residues 1-258) plays an important regulatory role in facilitating the catalytic function of the C-terminal domain (residues 259-460). The N-terminal domain alone does not show any activity. The C-terminal domain alone is much less active comparing to the full-length protein. The full-length protein is 13 times more active than the C-terminal domain alone. 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 mutant lacking both VC_A0681 and VC_A0931 shows 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.