Protein targets for disease intervention through inhibition of nucleic acid metabolism are disclosed. Novel polypeptides for one such target, DNA-dependent ATPase A, and novel polynucleotides encoding DNA-dependent ATPase A are disclosed. Phosphoaminoglycoside compounds which act on such protein targets to inhibit nucleic acid metabolism. In addition, screening assays for identifying compounds that inhibit nucleic acid-dependent ATPase activity, including, but not limited to, DNA-dependent ATPase A, are disclosed. Such compounds are useful in the treatment of diseases, including but not limited to cancer and infectious disease, through disruption of nucleic acid metabolism and induction of apoptosis. Moreover, methods for prevention and treatment of diseases including, but not limited to cancer and infectious disease are disclosed.