FIGURE 1.

Cell-free synthetic biology reaction formats and strategies. (i) Recombinant enzymes can be mixed together along with enzyme co-factors and substrates to form biosynthetic pathways. (ii) The PURE cell-free protein synthesis system utilizes reconstituted Escherichia coli transcription and translation machinery, DNA templates, purified enzymes and other factors. (iii) Cell extracts from lysed wildtype or engineered cells can be mixed together along with enzyme co-factors and substrates to form biosynthetic pathways. (iv) Cell extract-based cell-free protein synthesis reactions utilize the transcription and translation machinery within cell lysates, along with exogenously added energy mix components (e.g., amino acids) and DNA templates for in vitro protein production.