Participates in a DNA-damage check-point that is active prior to asymmetric division when DNA is damaged (PubMed:9141693, PubMed:16713562). Forms globular foci that rapidly scan along the chromosomes during sporulation, searching for lesions. Its ability to scan through the chromosome rapidly is due to its non-specific DNA-binding. When a lesion is present, DisA pauses at the lesion site (PubMed:21566650). This triggers a cellular response that culminates in a temporary block in sporulation initiation. It is required, at least partially, to inhibit the activity of the transcription factor spo0A, which controls, among others, early sporulation genes. In B.subtilis c-di-AMP is a second messenger that mediates growth, DNA repair and cell wall homeostasis (PubMed:22211522); it is toxic when present in excess (PubMed:26240071). One of 3 paralogous diadenylate cyclases (DAC) in this bacteria (PubMed:23192352). Has diadenylate cyclase activity, catalyzing the condensation of 2 ATP molecules into cyclic di-AMP (c-di-AMP) (PubMed:18439896, PubMed:25616256). c-di-AMP acts as a signaling molecule that couples DNA integrity with progression of sporulation. The rise in c-di-AMP level generated by DisA while scanning the chromosome operates as a positive signal that advances sporulation; upon encountering a lesion, the DisA focus arrests at the damaged site and halts c-di-AMP synthesis. Does not convert GTP to c-di-GMP (PubMed:18439896). 2 ATP = 3',3'-c-di-AMP + 2 diphosphate Diadenylate cyclase activity is inhibited by the interaction with RadA (By similarity). Diadenylate cyclase activity is not affected by ssDNA or dsDNA, but three- and four-way junctions strongly inhibit the activity of DisA, suggesting the enzyme is regulated by branched nucleic acids. Homooligomer (PubMed:18439896). Interacts with RadA (PubMed:23760274). Present in a puncate pattern at 1.5 hours after sporulation onset, does not co-localize with c-di-AMP phosphodiesterase GdpP. Expression increases during late exponential phase and at the onset of sporulation (PubMed:16713562). Transcribed under partial control of SigM ECF sigma factor (PubMed:17434969). Decreases c-di-AMP levels in mid-exponential phase from about 3.8 uM to about 2.8 uM in strain BG214 (PubMed:25616256). No change in sensitivity to methyl methanesulfonate (MMS), decreased survival after UV irradiation in transition and stationary phase, strong decrease in competence (PubMed:9141693). Cells lacking this gene show a reduced c-di-AMP level compared to wild-type and cannot properly trigger the DNA damage response (PubMed:21566650). No effect on antibiotic sensitivity to the beta-lactam antibiotic cefuroxime (CEF), upon overexpression of the c-di-AMP phosphodiesterase GdpP 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 100-fold more sensitive to MMS, no change in response to H(2)O(2) or nalidixic acid; a double disA-radA deletion suppresses H(2)O(2) sensitivity of the radA mutant, but has no effect on MMS sensitivity, suggesting radA and disA might work in the same DNA repair pathway (PubMed:25616256). Belongs to the DisA family.