Synthetic protein–protein interaction domains created by shuffling Cys2His2 zinc-fingers

Cys2His2 zinc-fingers (C2H2 ZFs) mediate a wide variety of protein-DNA and protein-protein interactions. DNA-binding C2H2 ZFs can be shuffled to yield artificial proteins with different DNA binding specificities. Here we demonstrate that shuffling of C2H2 ZFs from transcription factor dimerization zinc-finger (DZF) domains can also yield two-finger DZFs with novel protein-protein interaction specificities. We show that these synthetic protein-protein interaction domains can be used to mediate activation of a single-copy reporter gene in bacterial cells and of an endogenous gene in human cells. In addition, the synthetic two-finger domains we constructed can also be linked together to create more extended, four-finger interfaces. Our results demonstrate that shuffling of C2H2 ZFs can yield artificial protein-interaction components that should be useful for applications in synthetic biology.