Catalyzes the reversible transfer of the terminal phosphate group between ATP and AMP (PubMed:18973776). Has very low activity with CTP, GTP, ITP and UTP and no activity with GMP, UMP or IMP in vitro (PubMed:18973776). AMP + ATP = 2 ADP kcat is 5.4 sec(-1) (at 25 degrees Celsius and pH 7.6). Optimum pH is 8. Monomer (PubMed:18973776). Oligomer (PubMed:18973776). Heterodimer composed of NMT and AK2; AK2 myristoylation stabilizes the complex (PubMed:18973776). Localizes to the vacuolar side of the parasitophorous vacuole. Myristoylation is required for cell membrane localization. May be palmitoylated at Cys-4 which stabilizes cell membrane localization of the myristoylated protein. Belongs to the adenylate kinase family.