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 (By similarity). Negatively regulates Rho activity by interacting with AKAP13/LBC. Acts as a transcriptional activator of the MYC gene; binds DNA non-specifically. Binds to both single-stranded guanine- and cytosine-rich strands within the nuclease hypersensitive element (NHE) III(1) region of the MYC gene promoter. Does not bind to duplex NHE III(1). Has G-quadruplex (G4) DNA-binding activity, which is independent of its nucleotide-binding and kinase activity. Binds both folded and unfolded G4 with similar low nanomolar affinities. Stabilizes folded G4s regardless of whether they are prefolded or not. Exhibits histidine protein kinase activity (By similarity). a 2'-deoxyribonucleoside 5'-diphosphate + ATP = a 2'-deoxyribonucleoside 5'-triphosphate + ADP a ribonucleoside 5'-diphosphate + ATP = a ribonucleoside 5'-triphosphate + ADP ATP + protein L-histidine = ADP + protein N-phospho-L-histidine. Hexamer of two different chains: A and B (A6, A5B, A4B2, A3B3, A2B4, AB5, B6) (By similarity). Interacts with CAPN8 (PubMed:16476741). Interacts with AKAP13 (By similarity). Interacts ITGB1BP1 (via C-terminal domain region) (By similarity). Interacts with BCL2L10 (PubMed:17532299). Colocalizes with ITGB1 and ITGB1BP1 at the edge or peripheral ruffles and lamellipodia during the early stages of cell spreading on fibronectin or collagen but not on vitronectin or laminin substrates. Expressed in the base region of the oxyntic and pyloric mucosae. Impaired activation of the K(+) channel Kcnn4, resulting in defective T-cell activation. Belongs to the NDK family.