Expanding tryptophan-containing cyclodipeptide synthase spectrum by identification of nine members from Streptomyces strains

• Published in: Applied microbiology and biotechnology Vol. 102; no. 10; pp. 4435 - 4444
• Main Authors: Liu, Jing, Yu, Huili, Li, Shu-Ming
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2018; Springer; Springer Nature B.V
• Subjects: Amino acids; Bacteria; Biomedical and Life Sciences; Biosynthesis; Biotechnologically Relevant Enzymes and Proteins; Biotechnology; Cloning; DNA methylation; E coli; Enzymes; Escherichia coli; Escherichia coli - genetics; Fungi; Gene expression; Genes; Life Sciences; Machinery and equipment; Microbial Genetics and Genomics; Microbiology; Microorganisms; Peptide Synthases - chemistry; Peptide Synthases - genetics; Peptide Synthases - isolation & purification; Peptides; Physiological aspects; Plasmids; Strains (organisms); Streptomyces; Streptomyces - classification; Streptomyces - enzymology; Synthetic biology; Transfer RNA; Tryptophan; Tryptophan - genetics; Cyclodipeptide synthase; Tryptophan-containing cyclodipeptide; Aminoacyl t-RNA; Diketopiperazine; Streptomyces
• DOI: 10.1007/s00253-018-8908-6
• ISSN: 0175-7598; 1432-0614

Cyclodipeptide synthases (CDPSs) comprise normally 200–300 amino acid residues and are mainly found in bacteria. They hijack aminoacyl-tRNAs from the ribosomal machinery for cyclodipeptide formation. In this study, nine new CDPS genes from eight Streptomyces strains were cloned into pET28a vector and expressed in Escherichia coli . Structural elucidation of the isolated products led to the identification of one cyclo - l -Trp- l -Leu, two cyclo - l -Trp- l -Pro, and three cyclo - l -Trp- l -Trp synthases. Other three CDPSs produce cyclo - l -Trp- l -Ala or cyclo - l -Trp- l -Tyr as the major cyclodipeptide. Total product yields of 46 to 211 mg/L E. coli culture were obtained. Our findings represent rare examples of CDPS family derived from actinobacteria that form various tryptophan-containing cyclodipeptides. Furthermore, this study highlights the potential of the microbial machinery for tryptophan-containing cyclodipeptide biosynthesis and provides valid experimental basis for further combination of these CDPS genes with other modification genes in synthetic biology.