Involved 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 (By similarity). a 2'-deoxyribonucleoside 5'-diphosphate + ATP = a 2'-deoxyribonucleoside 5'-triphosphate + ADP a ribonucleoside 5'-diphosphate + ATP = a ribonucleoside 5'-triphosphate + ADP A number of isoforms are produced. According to EST sequences. Belongs to the NDK family.