A nonribosomal peptide synthetase (NRPS) gene cluster (sfa) was identified in Streptomyces thioluteus to direct the biosynthesis of the diisonitrile antibiotic SF2768. Its biosynthetic pathway was reasonably proposed based on bioinformatics analysis, metabolic profiles of mutants, and the elucidation of the intermediate and shunt product structures. Bioinformatics-based alignment found a putative ATP-binding cassette (ABC) transporter related to iron import within the biosynthetic gene cluster, which implied that the product might be a siderophore. However, characterization of the metal-binding properties by high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), metal–ligand titration, thin-layer chromatography (TLC), and chrome azurol S (CAS) assays revealed that the final product SF2768 and its diisonitrile derivatives specifically bind copper, rather than iron, to form stable complexes. Inductively coupled plasma mass spectrometry (ICP-MS) analysis revealed that the intracellular cupric content of S. thioluteus significantly increased upon incubation with the copper–SF2768 complex, direct evidence for the copper acquisition function of SF2768. Further in vivo functional characterization of the transport elements for the copper–SF2768 complexes not only confirmed the chalkophore identity of the compound but also gave initial clues into the copper uptake mechanism of this nonmethanotrophic microorganism.

中文翻译：

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Diisonitrile天然产物SF2768充当介导硫代链霉菌中的铜获得的媒介物。

阿非核糖体肽合成酶（NRPS）基因簇（SFA）中被鉴定链霉菌thioluteus指导二异腈抗生素SF2768的生物合成。基于生物信息学分析，突变体的代谢谱以及对中间产物和分流产物结构的阐明，合理地提出了其生物合成途径。基于生物信息学的比对发现了一个推测的ATP结合盒（ABC）转运蛋白，与生物合成基因簇中的铁导入有关，这暗示该产物可能是铁载体。但是，通过高分辨率电喷雾电离质谱（HR-ESI-MS），金属-配体滴定，薄层色谱（TLC）和铬天青S（CAS）分析表征金属结合性能产品SF2768及其二异腈衍生物与铜而不是铁特异性结合，形成稳定的络合物。小号。与铜–SF2768复合物孵育后，硫脲显着增加，这是SF2768铜获取功能的直接证据。铜-SF2768配合物的转运元素的进一步体内功能表征不仅证实了化合物的垩基身份，而且为这种非甲烷营养微生物的铜吸收机理提供了初步线索。