Cell-free protein synthesis (CFPS) systems are emerging as effective platforms for the production of recombinant proteins in vitro. To enable the expression of various proteins, different CFPS systems have been developed to better mimic the cellular environment of native hosts. In this context, a Streptomyces-based CFPS system was recently developed to express high GC-content genes. Unfortunately, protein yields from the initial system were relatively low (∼50 μg/mL). Here, we sought to address this limitation and enhance the productivity of the Streptomyces-based CFPS system. By adding protein translation related factors to CFPS reactions, we were able to achieve protein yields of approximately 400 μg/mL, which is the highest yield reported to date. We expect our enhanced Streptomyces CFPS system will set the stage for novel applications in metabolic engineering and synthetic biology such as in vitro discovery and synthesis of natural products, which are produced by Streptomyces species with high GC-content (>70%) genomes.
Keywords: Streptomyces; cell-free protein synthesis; in vitro transcription and translation; protein expression; synthetic biology.