在Caulobacter crescentus中,hiuABC操作子介导着异体利用
Sergio Hernandez-Ortiz1, Aretha Fiebig1, Sean Crosson1
1Department of Microbiology, Genetics & Immunology, Michigan State University, East Lansing, MI, USA.
bioRxiv : the preprint server for biology
|September 15, 2025
概括
半月菌 (Caulobacter crescentus) 使用HiuABC系统从环境中的 siderophores中清理铁. 这种保存的操作子可以从各种酸盐 siderophores 获取铁,这对于在铁有限的环境中生存至关重要.
科学领域:
- 微生物学 微生物学
- 细菌生理学 细菌生理学
- 铁的新陈代谢 铁的新陈代谢
背景情况:
- 菌种类居住在缺乏铁的环境中,因此需要有效的铁获取策略.
- 像Caulobacter crescentus这样的皮肤细菌利用外膜TonB依赖转运体 (TBDTs) 来吸收铁性 siderophore 复合体.
- C. crescentus 缺乏已知的 siderophore 合成,但拥有多个由铁吸收抑制剂 (Fur) 调节的 TBDTs,这表明 xenosiderophore 清理.
研究的目的:
- 在C. crescentus中识别基因,这些基因对于利用外部 siderophores (xenosiderophores) 来获得铁是必不可少的.
- 描述已识别的HiuABC系统在酸酸盐家族 siderophores 的铁吸收中的功能.
主要方法:
- 使用费里奥克萨B (FXB) 作为模型酸盐 siderophore,采用了带条码的转子子屏幕.
- 进行了基因分析,以确定HiuA,HiuB和HiuC在获得铁中的作用.
- 对铁胺和铁 (FC) 的基质特异性进行了评估.
主要成果:
- 保存的,毛皮调节的 hiuABC 操作子被确定为ferrioxamine B (FXB) 获得铁的关键.
- HiuA 作为 ferrioxamines 和 ferrichrome (FC) 的主要 TBDT 的功能.
- HiuB和HiuC形成了FXB和铁氧胺E (FXE) 利用所需的复合体,而HiuC对于FC吸收是不可缺少的,表明基质特定的作用.
结论:
- hiuABC 操作子使 C. crescentus 能够从结构上多样化的酸酸盐家族 siderophores 中获得铁.
- 这个系统对于细菌的生存和铁在稀缺生态系统中的铁平衡至关重要.
- 这些发现揭示了在细菌中利用异体的保存机制.
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