Comprehensive derivatization of thiostrepton via heterologous expression

Area of Science:

• Biochemistry
• Microbiology
• Synthetic Biology

Background:

• Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a diverse class of natural products.
• Thiostrepton is a potent antibiotic belonging to the thiopeptide class of RiPPs.
• Developing efficient methods for thiostrepton derivatization is crucial for exploring its chemical space and discovering new antibiotics.

Purpose of the Study:

• To optimize a previously developed derivatization technology for thiostrepton metabolites.
• To generate novel thiostrepton derivatives with potential antimicrobial activities.
• To investigate the structure-activity relationship of thiostrepton derivatives.

Main Methods:

• Optimization of thioamide derivatization technology for thiostrepton.
• Development of a heterologous expression system using engineered Streptomyces avermitilis.
• Generation and characterization of thiostrepton derivatives through amino acid substitutions.
• Antimicrobial activity testing against gram-positive bacteria.
• Analysis of tipA promoter induction by thiostrepton and its derivatives.

Main Results:

• Efficient thiostrepton derivatization was achieved using optimized procedures.
• A heterologous expression system facilitated high-performance metabolite production.
• Twenty designed thiostrepton derivatives and novel analogs were produced via heterologous expression.
• Derivatives with specific amino acid substitutions (Ala to Ser or Val) exhibited improved antibacterial activity.
• Antimicrobial activity correlated with tipA promoter induction.

Conclusions:

• The optimized strategy is effective for generating novel non-natural metabolites.
• Thiostrepton derivatives with enhanced antibacterial properties were successfully synthesized.
• The correlation between antimicrobial activity and tipA promoter induction provides insights into the mechanism of action.