CBASS (cyclic oligonucleotide-based antiphage signaling system) provides immunity against bacteriophage. The CD-NTase protein synthesizes cyclic nucleotides in response to infection; these serve as specific second messenger signals. The signals activate a diverse range of effectors, leading to bacterial cell death and thus abortive phage infection. A type I-D CBASS(GG) system (PubMed:32839535). Binds c-di-GMP (synthesized by the cognate CdnE encoded upstream in the same operon) and about 10-fold less well 3'3'-cGAMP, but not c-di-AMP, 2'3'-cGAMP or cUMP-AMP (tested with a protein without the transmembrane region) (PubMed:32877915). The effector protein for this CBASS system, its activity is stimulated by c-di-GMP and leads to cell death (Probable). The cyclic nucleotide binds in the C-terminal bacterial STING region. In the C-terminal section; belongs to the bacterial STING family. Truncated N-terminus.