Has phosphodiesterase (PDE) activity against cyclic-di-AMP (c-di-AMP) and to a much lesser extent against cyclic-di-GMP (c-di-GMP) in the DHH/DHHA1 domains (PubMed:19901023, PubMed:21257773). Also has ATPase activity, probably via the GGDEF domain (PubMed:19901023, PubMed:21257773). Overexpression leads to increased sensitivity to methyl methanesulfonate (MMS) and H(2)O(2) (PubMed:25616256). Overexpression leads to extreme sensitivity to the beta-lactam antibiotic cefuroxime (CEF), probably dependent on PDE activity (PubMed:22211522). May monitor cellular heme or NO levels (PubMed:21257773). 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). 3',3'-c-di-AMP + H2O = 5'-O-phosphonoadenylyl-(3'->5')-adenosine + H(+) Binds 1 heme (probably heme b) per subunit, probably hexa-coordinated, which inhibits PDE and ATPase. The Fe(2+) binds CN(-), CO and NO. ATPase activity (residues 84-303) prefers Mg(2+) over Mn(2+). For phosphodiesterase activity (residues 84-695), probably binds 2 Mn(2+) per subunit, can also use Co(2+), Mg(2+) or Ni(2+). Phosphodiesterase (PDE) inhibited by Zn(2+), Ca(2+) inhibits in the presence of Mg(2+) but not Mn(2+); c-di-AMP PDE activity is competitively inhibited by ppGpp (PubMed:19901023). Heme binding (by Fe(2+) or Fe(3+) heme) inhibits PDE, activity is partially restored by KCN or NO only for Fe(2+) heme (PubMed:21257773). Binding of NO to Fe(2+) heme switches from hexa- to pentacoordination (PubMed:21257773). Heme binding inhibits the ATPase activity (PubMed:21257773). Phosphodiesterase kcat 0.55 for c-di-AMP, 0.23 for c-di-GMP, tested for a construct expressing residues 84-695, a shorter construct (residues 150-695) has a 10-fold decreased kcat for both substrates. ATPase kcat 0.59. Optimum pH is 8.5-9.2 (for a construct expressing residues 84-695). After 3.5 hours of sporulation is present in a punctate pattern associated with the cell membrane. Does not co-localize with c-di-AMP synthase DisA. Expressed at low levels at the onset of sporulation, it rises during sporulation (at protein level). Probably transcribed under control of the sigma A factor (sigA), protein levels are negatively regulated by an antisense RNA (PubMed:22956758). Has a GGDEF domain (residues 173-310) preceded by a PAS-like domain (residues 84-149) which together have ATPase activity, followed by a region with a DHH (339-496) and a DHHA1 (591-646) domain (PubMed:19901023). The combined GGDEF, DHH and DHHA1 domains have c-di-AMP phosphodiesterase activity (residues 150-659) that is 10-fold enhanced by inclusion of the PAS-like domain (84-149); PDE activity may only require the DHH/DHHA1 domains (PubMed:19901023). The PAS-like domain is important for heme b-binding (PubMed:21257773). Increased resistance to acid stress, increased sporulation efficiency following DNA damage (by nalidixic acid) (PubMed:19901023). Increases c-di-AMP levels in mid-exponential phase from about 3.8 uM to about 4.3 uM in strain BG214 (PubMed:25616256). Increased levels of c-di-AMP 4-fold during sporulation (PubMed:21566650). Insertion mutations in this gene partially restore antibiotic resistance to the beta-lactam antibiotic cefuroxime (CEF) in a sigM deletion mutant (PubMed:22211522). Decreased sensitivity to MMS and H(2)O(2) (PubMed:25616256). In strain 168 grown in minimal medium and glutamate, 2.2-fold increase in c-di-AMP levels while a double pgpH-gdpP mutant has 4.2-fold increased levels of in c-di-AMP; double mutants die on solid medium after 2 days (PubMed:26240071). Belongs to the GdpP/PdeA phosphodiesterase family.