Sugar-nonspecific endonuclease that yields nucleotide 3'-monophosphate products. No 5'-nucleotidase activity was detected, using 5'-AMP as the substrate, in the presence of diverse divalent metals and with various pH values. Requires a minimum of 0.1 mM of calcium for a significant activity. Maximal activity was observed with concentrations of calcium between 1 to 5 mM. Is 10-fold less active with the corresponding concentrations of manganese. Inhibited by NaCl at concentrations of 100 mM and higher. Optimum pH is 9.0. Anchored to the cell wall by sortase SrtD. In the C-terminal section; belongs to the 5'-nucleotidase family.