背景:天黑链霉菌的几种双组分系统,一种用于研究链霉菌中抗生素生产的模型生物,影响编码细菌铁蛋白的bfr(SCO2113)基因的表达,参与铁储存的蛋白质。在这项工作中,我们已经研究了缺失突变体Δbfr在天色链球菌中的作用。
结果:在复杂培养基上,与野生型相比,Δbfr突变体在形态分化方面表现出延迟,并产生较少量的两种色素抗生素(放线菌素和十一糖苷)。在野生型和Δbfr突变体中测试了铁在基本培养基中的作用。因此,我们还观察到两种菌株之间两种色素抗生素的产生水平不同,取决于铁的浓度和介质(固体或液体)使用。与预期相反,在野生型和Δbfr突变体之间没有检测到细胞内铁浓度的差异。然而,Δbfr突变体中活性氧的含量较高,对氧化应激的耐受性较高。蛋白质组学分析显示铁反应蛋白没有变化,但是与放线菌蛋白和核糖体蛋白相关的蛋白质丰度较低,以及其他与次生代谢产物产生和分化有关的物质。此外,与各种类型的压力相关的蛋白质的丰度更高,比如呼吸和缺氧,也透露了。数据可通过具有标识符PXD050869的ProteomeXchange获得。
结论:天色链球菌中的这种细菌铁蛋白(Bfr)是天色链球菌次级代谢复杂调节的新元素,此外,铁作为信号调节活性分子的生物合成。我们的模型提出了Bfr与含铁调节蛋白之间的相互作用。因此,确定这些相互作用将为改善链霉菌中抗生素的生产提供新的信息。
BACKGROUND: Several two-component systems of Streptomyces coelicolor, a model organism used for studying antibiotic production in Streptomyces, affect the expression of the bfr (SCO2113) gene that encodes a bacterioferritin, a protein involved in iron storage. In this work, we have studied the effect of the deletion mutant ∆bfr in S. coelicolor.
RESULTS: The ∆bfr mutant exhibits a delay in morphological differentiation and produces a lesser amount of the two pigmented antibiotics (actinorhodin and undecylprodigiosin) compared to the wild type on complex media. The effect of iron in minimal medium was tested in the wild type and ∆bfr mutant. Consequently, we also observed different levels of production of the two pigmented antibiotics between the two strains, depending on the iron concentration and the medium (solid or liquid) used. Contrary to expectations, no differences in intracellular iron concentration were detected between the wild type and ∆bfr mutant. However, a higher level of reactive oxygen species in the ∆bfr mutant and a higher tolerance to oxidative stress were observed. Proteomic analysis showed no variation in iron response proteins, but there was a lower abundance of proteins related to actinorhodin and ribosomal proteins, as well as others related to secondary metabolite production and differentiation. Additionally, a higher abundance of proteins related to various types of stress, such as respiration and hypoxia among others, was also revealed. Data are available via ProteomeXchange with identifier PXD050869.
CONCLUSIONS: This bacterioferritin in S. coelicolor (Bfr) is a new element in the complex regulation of secondary metabolism in S. coelicolor and, additionally, iron acts as a signal to modulate the biosynthesis of active molecules. Our model proposes an interaction between Bfr and iron-containing regulatory proteins. Thus, identifying these interactions would provide new information for improving antibiotic production in Streptomyces.