文摘
Synthetic biology and protein origami both require protein building blocks that behave in a reliable, predictable fashion. In particular, we require protein interaction modules with known specificity and affinity. Here, we describe three designed TRAP (Tetratricopeptide Repeat Affinity Protein)鈥損eptide interaction pairs that are functional in vivo. We show that each TRAP binds to its cognate peptide and exhibits low cross-reactivity with the peptides bound by the other TRAPs. In addition, we demonstrate that the TRAP鈥損eptide interactions are functional in many cellular contexts. In extensions of these designs, we show that the binding affinity of a TRAP鈥損eptide pair can be systematically varied. The TRAP鈥損eptide pairs we present thus represent a powerful set of new building blocks that are suitable for a variety of applications.