Establishing a high yielding streptomyces-based cell-free protein synthesis system

Area of Science:

• Biotechnology and Synthetic Biology
• Microbial Engineering
• Molecular Biology

Background:

• Cell-free protein synthesis (CFPS) is a versatile tool for biotechnology and synthetic biology.
• Existing CFPS systems often struggle with expressing high GC-content genes, common in certain microbial species.

Purpose of the Study:

• To develop and optimize a Streptomyces-based CFPS system for efficient expression of GC-rich genes.
• To improve protein yields and solubility for complex gene clusters.

Main Methods:

• Developed a streamlined crude extract preparation protocol for Streptomyces.
• Optimized reaction conditions for batch and semi-continuous CFPS formats.
• Compared the Streptomyces system with an Escherichia coli-based CFPS system.

Main Results:

• Achieved EGFP yields >50 μg/mL in batch reactions and 282 ± 8 μg/mL in semi-continuous reactions.
• Demonstrated robustness across multiple Streptomyces strains.
• Showed improved soluble protein expression for high GC-content Streptomyces genes compared to E. coli CFPS.

Conclusions:

• The optimized Streptomyces CFPS system is effective for expressing GC-rich genes.
• This system offers advantages for studying natural product biosynthesis pathways, including nonribosomal peptides and polyketides.
• Provides a new avenue for obtaining and analyzing complex natural products.