Isolation and Biosynthetic Analysis of Haliamide, a New PKS-NRPS Hybrid Metabolite from the Marine Myxobacterium Haliangium ochraceum

Molecules

Yuwei Sun¹  Tomohiko Tomura¹  Junichi Sato¹  Takashi Iizuka²  Ryosuke Fudou³  Makoto Ojika¹ 

[1] Graduate School of Bioagricultural Sciences, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan;Institute for Innovation, Ajinomoto Co., Inc., Kawasaki, Kanagawa 210-8681, Japan;R & D Planning Department, Ajinomoto Co., Inc., Chuo-ku, Tokyo 104-8315, Japan;

关键词: marine myxobacterium;    Haliangium ochraceum;    haliamide;    polyketide;    biosynthesis;   

DOI  :  10.3390/molecules21010059

来源: mdpi

【 摘 要 】

Myxobacteria of marine origin are rare and hard-to-culture microorganisms, but they genetically harbor high potential to produce novel antibiotics. An extensive investigation on the secondary metabolome of the unique marine myxobacterium Haliangium ochraceum SMP-2 led to the isolation of a new polyketide-nonribosomal peptide hybrid product, haliamide (1). Its structure was elucidated by spectroscopic analyses including NMR and HR-MS. Haliamide (1) showed cytotoxicity against HeLa-S3 cells with IC₅₀ of 12 μM. Feeding experiments were performed to identify the biosynthetic building blocks of 1, revealing one benzoate, one alanine, two propionates, one acetate and one acetate-derived terminal methylene. The biosynthetic gene cluster of haliamide (hla, 21.7 kbp) was characterized through the genome mining of the producer, allowing us to establish a model for the haliamide biosynthesis. The sulfotransferase (ST)-thioesterase (TE) domains encoded in hlaB appears to be responsible for the terminal alkene formation via decarboxylation.

【 授权许可】

CC BY   
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