One of 3 paralogous diadenylate cyclases (DAC) in this bacteria catalyzing the condensation of 2 ATP molecules into cyclic di-AMP (c-di-AMP). It has slow DAC activity with ADP as a substrate and may have weak ADPase activity (PubMed:26441857). Required for efficient spore formation, whereas in B.subtilis, it is required for efficient spore germination. It is produced under the control of different sigma factors in the two bacteria. It is also required for parasporal crystal formation (PubMed:26441857). 2 ATP = 3',3'-c-di-AMP + 2 diphosphate Optimum pH is 7.5. Probably forms a homohexamer (PubMed:26441857). Probably expressed only during sporulation. First expressed at onset of sporulation, maximal transcription at 18 hours during sporulation in mid-stationary phase. Under control of sigma-H factor; in B.subtilis is under control of the sigma-G factor. The N-terminal region (residues 1-69) is required for activity, unlike the B.subtilis ortholog where their removal increases c-di-AMP production. Spore formation delayed by about 2 hours, about 20-fold decrease in spore formation; 2-fold decrease in parasporal crystal formation, 30% decreased c-di-AMP levels at 18 hours growth. Double cdaS-disA and cdaS-cdaA mutants are viable, but neither double cdaA-disA nor triple cdaA-cdaS-disA mutants can be made, suggesting c-di-AMP is essential. This strain no longer produces parasporal crystals, but can be made to do so upon transformation with appropriate plasmids. Belongs to the adenylate cyclase family. DacB/CdaS subfamily.