Enables nicotinamide-nucleotide adenylyltransferase activity. Acts upstream of or within NAD biosynthetic process and response to wounding. Located in mitochondrion. Is expressed in several structures, including alimentary system; hemolymphoid system; liver; and urinary system. Orthologous to human NMNAT3 (nicotinamide nucleotide adenylyltransferase 3). [provided by Alliance of Genome Resources, Apr 2022]