Major role in the synthesis of nucleoside triphosphates other than ATP. The ATP gamma phosphate is transferred to the NDP beta phosphate via a ping-pong mechanism, using a phosphorylated active-site intermediate. (Microbial infection) Catalyzes the phosphorylation of dZDP to dZTP, when the bacterium is infected by a phage that produces the substrate for the synthesis of dZTP (2- amino-2'-deoxyadenosine 5'-triphosphate), which is then used by the phage as a DNA polymerase substrate. ATP + dZDP = ADP + dZTP a 2'-deoxyribonucleoside 5'-diphosphate + ATP = a 2'-deoxyribonucleoside 5'-triphosphate + ADP a ribonucleoside 5'-diphosphate + ATP = a ribonucleoside 5'-triphosphate + ADP Purine metabolism. Homotetramer. Belongs to the NDK family.