Rapid Optimization of Engineered Metabolic Pathways with Serine Integrase Recombinational Assembly (SIRA)

Area of Science:

• Synthetic Biology
• Metabolic Engineering
• Biotechnology

Background:

• Microbial hosts offer sustainable production of chemicals via metabolic pathway engineering.
• Optimizing metabolic pathways requires balancing gene expression, enzyme activity, and metabolic flux.
• Current DNA assembly methods are a bottleneck in metabolic engineering.

Purpose of the Study:

• To introduce and validate Serine Integrase Recombinational Assembly (SIRA) as a rapid DNA assembly method.
• To demonstrate SIRA's utility in optimizing engineered metabolic pathways.
• To provide protocols and practical methods for applying SIRA.

Main Methods:

• Utilized six pairs of orthogonal attP and attB sites with distinct central dinucleotide sequences.
• Employed ΦC31 integrase for DNA manipulation.
• Developed one-pot reactions for assembling multiple DNA parts and generating combinatorial libraries.

Main Results:

• Successfully inserted single DNA fragments into plasmids.
• Assembled three, four, and five DNA parts for functional metabolic pathways in one-pot reactions.
• Generated combinatorial libraries with varied ribosome binding site strengths and gene orders.
• Enabled targeted post-assembly modification for DNA part replacement and addition.

Conclusions:

• SIRA is a versatile and efficient method for rapid DNA assembly in metabolic engineering.
• SIRA facilitates the optimization of complex metabolic pathways.
• The study provides a practical framework for implementing SIRA in microbial biosynthesis applications.