Fig. 1

Cell-free protein expression systems and their applications. Capitalizing on their open nature, CFS can be rationally assembled to include cell lysates, purified proteins, energy sources (e.g., ATP), amino acids, other substrates (such as modified tRNAs and membrane mimics) and RNA or DNA (circular or linear). CFS can be applied in portable diagnostic devices [46, 50] and also hold great potential for biomolecular manufacturing [49, 51]. Additionally, CFS can enable discovery of novel enzymes (e.g., through directed evolution) [52]