Involved in maintaining the homeostasis of cellular nucleotides by catalyzing the interconversion of nucleoside phosphates (By similarity). Efficiently phosphorylates AMP and dAMP using ATP as phosphate donor, but phosphorylates only AMP when using GTP as phosphate donor (By similarity). Also displays broad nucleoside diphosphate kinase activity (By similarity). Plays a role in controlling cellular ATP levels by regulating phosphorylation and activation of the energy sensor protein kinase AMPK (By similarity). Plays a protective role in the cellular response to oxidative stress (By similarity). a ribonucleoside 5'-triphosphate + AMP = a ribonucleoside 5'-diphosphate + ADP a 2'-deoxyribonucleoside 5'-diphosphate + ATP = a 2'-deoxyribonucleoside 5'-triphosphate + ADP a ribonucleoside 5'-diphosphate + ATP = a ribonucleoside 5'-triphosphate + ADP Monomer (By similarity). Interacts with SLC25A5/ANT2 (By similarity). Consists of three domains, a large central CORE domain and two small peripheral domains, NMPbind and LID, which undergo movements during catalysis. The LID domain closes over the site of phosphoryl transfer upon GTP/ATP binding. Assembling and dissambling the active center during each catalytic cycle provides an effective means to prevent GTP/ATP hydrolysis. Belongs to the adenylate kinase family. AK3 subfamily.