The self-assembly of nanosized DNA templates—based on formation of duplex, triplex, quadruplex or even pentaplex structures—provides unique opportunities for the controlled presentation of appended functional units. Recently, researchers have recognized the potential of such DNA scaffolds to address questions in the life sciences. In this critical review the focus is on the exploration of proteins. It is shown how different scaffolds can be used to control localization, structure and bioactivity of proteins and protein ligands. Further examples demonstrate that DNA-based recognition can even be used to trigger the formation of protein targeted molecules. Potential and existing applications in protein detection, drug discovery, structural characterization of protein targets as well as in the design of nucleic acid responsive pharmacophores are discussed