Identification and Heterologous Expression of the Kendomycin B Biosynthetic Gene Cluster from Verrucosispora sp. SCSIO 07399

• Published in: Marine drugs Vol. 19; no. 12; p. 673
• Main Authors: Chen, Jiang, Zhang, Shanwen, Chen, Yingying, Tian, Xinpeng, Gu, Yucheng, Ju, Jianhua
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 26-11-2021; MDPI
• Subjects: Actinobacteria; Animals; Antibacterial activity; Antibiotics; Aquatic Organisms; Bioinformatics; Biosynthesis; China; Complementation; Cytotoxicity; Dihydroxybenzoic acid; Elongation; Enzymes; Gene disruption; Gene expression; Genes; Genomes; Gram-positive bacteria; heterologous expression; Hypotheses; Identification; kendomycin B; Multigene Family; Natural products; Neoplasms; Nucleotide sequence; Open reading frames; PCR; Polyketide synthase; Polyketides; Quinones; Rifabutin - analogs & derivatives; Rifabutin - metabolism; Scaffolds; Structure-Activity Relationship; Toxicity; Tumors; Verrucosispora sp. SCSIO 07399; China; kendomycin B; heterologous expression; Verrucosispora sp. SCSIO 07399; biosynthesis
• ISSN: 1660-3397; 1660-3397
• DOI: 10.3390/md19120673

sp. SCSIO 07399, a rare marine-derived actinomycete, produces a set of ansamycin-like polyketides kendomycin B-D (
-
) which possess potent antibacterial activities and moderate tumor cytotoxicity. Structurally, kendomycin B-D contain a unique aliphatic macrocyclic
scaffold in which the highly substituted pyran ring is connected to the quinone moiety. In this work, a type I/type III polyketide synthase (PKS) hybrid biosynthetic gene cluster coding for assembly of kendomycin B (
), and covering 33 open reading frames, was identified from
sp. SCSIO 07399. The
cluster was found to be essential for kendomycin B biosynthesis as verified by gene disruption and heterologous expression. Correspondingly, a biosynthetic pathway was proposed based on bioinformatics, cluster alignments, and previous research. Additionally, the role of type III PKS for generating the precursor unit 3,5-dihydroxybenzoic acid (3,5-DHBA) was demonstrated by chemical complementation, and type I PKS executed the polyketide chain elongation. The
cluster was found to contain a positive regulatory gene
whose regulatory effect was identified using real-time quantitative PCR (RT-qPCR). These advances shed important new insights into kendomycin B biosynthesis and help to set the foundation for further research aimed at understanding and exploiting the carbacylic
scaffold.