Evolution and Synthesis of New Function
Jason Chin

Networks of molecular interactions in organisms have evolved to allow the increase in complexity from unicellular organisms to metazoans via gene duplication followed by natural selection. The evolution of highly connected molecular hubs has been constrained by their connectivity. Yet, paradoxically, alteration of the function of just such cellular hubs offers the greatest potential for the addition of new function to living matter.

We have begun to explore the synthetic evolution and exploitation of duplicated versions of highly connected cellular hubs. In one example of this approach we have evolved multiple orthogonal ribosome•mRNA pairs in which the new mRNA is not a substrate for the endogenous ribosome and the new ribosome does not translate endogenous mRNAs. Moreover we have predicted and measured the molecular specificity of each orthogonal ribosome with respect to each orthogonal mRNA and vice versa. A knowledge of the interaction network has allow us to construct ribosome based genetic logic circuits composed of multiple ribosomes and their mRNA binding sites.