De novo design of protein logic gates

Designer gates Signaling in cells can occur through protein-protein interactions. Chen et al. describe the design of logic gates that can regulate protein association. The gates were built from small, designed proteins that all have a similar structure but where one module can be designed to interact specifically with another module. Using monomers and covalently connected monomers as inputs and encoding specificity through designed hydrogen-bond networks allowed the construction of two-input or three-input gates based on competitive binding. The modular control elements were used to regulate the association of elements of transcription machinery and split enzymes in vitro and in yeast cells. Science , this issue p. 78