Catalyzes the phosphorylation of ribonucleosides and deoxyribonucleoside diphosphates, other than ATP, into the corresponding triphosphates with ATP as the major phosphate donor (PubMed:11277919, PubMed:30587587). The ATP gamma phosphate is transferred to the nucleoside diphosphate beta phosphate via a ping-pong mechanism, using a phosphorylated active-site intermediate. Through the catalyzed exchange of gamma-phosphate between di- and triphosphonucleosides participates in regulation of intracellular nucleotide homeostasis (PubMed:11277919, PubMed:30587587). Inhibits granulocyte differentiation (PubMed:7638209). May be required for ciliary function during renal development (By similarity). ; Independently of its kinase activity, facilitates mitochondrial tethering prior to membrane fusion through its direct membrane-binding and hexamerization (PubMed:30587587, PubMed:37584589). Implicated in repair of both single- and double-stranded breaks in DNA through its association with the ribonucleotide reductase complex (RNR complex) via its interaction with the histone acetyltransferase KAT5, this interaction enables recruitment of NME3 at DNA damage sites where it plays a role in the repair of DNA, independently of its kinase activity (PubMed:37584589).
