Broad-specificity nucleoside monophosphate (NMP) kinase that catalyzes the reversible transfer of the terminal phosphate group between nucleoside triphosphates and monophosphates. AMP and dAMP are the preferred substrates, but CMP and TMP are also good substrates. ATP and dATP are the best phosphate donors. May have a role in nuclear energy homeostasis. AMP + ATP = 2 ADP Suppresses worm growth. Belongs to the adenylate kinase family. AK6 subfamily.