Mechanism of thiopeptide antibiotic biosynthesis enzyme revealed by Shanghai Institute of organic chemistry, Chinese Academy of Sciences

Shanghai organic Research Institute of Chinese Academy of Sciences first clarified the enzymatic mechanism of the key macrocyclization reaction during the formation of the side ring of thiostreptomycetin (TSR) The relevant results were published online in the Journal of National Academy of Sciences Thiopeptide antibiotics are a kind of ancient bioactive peptide antibiotics Related research is not only conducive to the production of new drug precursors by using the modified "microbial factory", but also expands people's understanding and recognition of post-translational modification of special proteins / peptides By optimizing the fermentation time of the mutant △ tsrt fed with 6-f-qa as the precursor, the team isolated and identified a key fluorine intermediate whose side ring had not been closed but whose QA group had been epoxidated The introduction of fluorine atom reduced the enzyme activity of the key protein which catalysed the formation of side ring, resulting in the short-term accumulation of intermediates, while continuing to extend the fermentation time, the intermediate would be transformed into the final mature 6 '- fluoro-tsr molecule The separation and identification of the intermediate lay an important foundation for the study of enzymatic mechanism in the biosynthesis pathway of TSR side ring The researchers identified a gene TSRI in the TSR biosynthesis gene cluster whose function has not yet been attributed, and the protein TSRI encoded belongs to the α / β hydrolase superfamily It has been confirmed that TSRI is the key protein in the biosynthesis of s-catenin side ring, which is responsible for the removal of the leading peptide and the macrocyclization of TSR side ring closure.