An engineered biosynthetic-synthetic platform for production of halogenated indolmycin antibiotics

Area of Science:

• Microbiology
• Synthetic Biology
• Medicinal Chemistry

Background:

• Indolmycin is a natural antibiotic produced by Streptomyces griseus with demonstrated activity against various pathogens.
• Existing methods for indolmycin production are limited, hindering the exploration of its derivatives.
• The biosynthesis pathway of indolmycin offers a target for genetic engineering and synthetic biology approaches.

Purpose of the Study:

• To engineer Escherichia coli for the production of indolmycenic acid, a crucial intermediate in indolmycin biosynthesis.
• To develop a platform for generating novel indolmycin derivatives by introducing a promiscuous tryptophanyl-tRNA synthetase.
• To synthesize and evaluate the bioactivity of new indolmycin analogs.

Main Methods:

• Utilized genes from the indolmycin biosynthetic pathway in an E. coli host system.
• Engineered E. coli by introducing a promiscuous tryptophanyl-tRNA synthetase (trpS) gene.
• Fed halogenated indoles to the engineered E. coli to produce corresponding indolmycenic acids.
• Synthesized indolmycin derivatives from the generated indolmycenic acids.
• Assessed the bioactivity of synthesized fluoro-indolmycin derivatives against methicillin-resistant Staphylococcus aureus.

Main Results:

• Successfully produced indolmycenic acid in E. coli.
• Generated a library of indolmycin derivatives by incorporating halogenated indoles.
• Synthesized 5-, 6-, and 7-fluoro-indolmycin derivatives.
• Demonstrated modest antibiotic activity of these fluoro-indolmycin derivatives against methicillin-resistant Staphylococcus aureus.

Conclusions:

• The engineered E. coli system provides a viable platform for producing indolmycin intermediates and derivatives.
• The synthetic approach allows for the expansion of indolmycin structural diversity.
• Novel indolmycin derivatives show potential as antimicrobial agents, warranting further investigation.