Has nicotinamidemononucleotide (NMN) aminohydrolase activity, not active on other substrates. beta-nicotinamide D-ribonucleotide + H2O = NH4(+) + nicotinate beta-D-ribonucleotide kcat is 3.3 sec(-1). Optimum pH active over a broad range of pH values. Homodimer. Belongs to the CinA family. PncC subfamily.