One of 3 paralogous diadenylate cyclases (DAC) in this bacteria, catalyzing the condensation of 2 ATP molecules into cyclic di-AMP (c-di-AMP) (Probable). Upon expression in E.coli leads to c-di-AMP synthesis (PubMed:23192352). Probably the main producer of c-di-AMP for the cell; is probably implicated in control of peptidogylcan synthesis (PubMed:22211522, PubMed:23192352, PubMed:26240071). In B.subtilis c-di-AMP is a second messenger that mediates growth, DNA repair and cell wall homeostasis; it is toxic when present in excess (PubMed:26240071). 2 ATP = 3',3'-c-di-AMP + 2 diphosphate DAC activity is stimulated about 20-fold in E.coli by coexpression with CdaR (PubMed:23192352). Probably a homodimer (By similarity). Interacts with CdaR (PubMed:23192352, PubMed:26240071). May interact with GlmM (PubMed:26240071). Constitutively expressed, part of the cdaA-cdaR-glmM-glmS operon (PubMed:23192352). Increased sensitivity to the beta-lactam antibiotic cefuroxime (CEF), upon overexpression of the c-di-AMP phosphodiesterase GdpP greatly increased sensitivity to CEF (PubMed:22211522). Double disA-cdaA mutants cannot be made, suggesting they are lethal, while double disA-cdaS and cdaA-cdaS mutants are viable (PubMed:22211522, PubMed:23192352). Depletion of cdaA in double disA-cdaA deletion cells leads to cell lysis (PubMed:22211522). Exponentially growing cells are extremely sensitive to H(2)O(2), no change in response to methyl methanesulfonate (PubMed:25616256). Belongs to the adenylate cyclase family. DacA/CdaA subfamily.