Diisonitrile Natural Product SF2768 Functions As a Chalkophore That Mediates Copper Acquisition in Streptomyces thioluteus.
Lijuan WangMengyi ZhuQingbo ZhangXu ZhangPanlei YangZihui LiuYun DengYiguang ZhuXue-Shi HuangLi HanShengqing LiJing HePublished in: ACS chemical biology (2017)
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.
Keyphrases
- mass spectrometry
- high resolution
- oxide nanoparticles
- liquid chromatography
- high performance liquid chromatography
- capillary electrophoresis
- ms ms
- gas chromatography
- genome wide
- copy number
- multiple sclerosis
- bioinformatics analysis
- single cell
- pulmonary artery
- high throughput
- binding protein
- dna methylation
- high speed
- pulmonary arterial hypertension
- genome editing
- reactive oxygen species