State Key Laboratory of Rice Biology and Ministry of Agriculture Key Laboratory of Molecular Biology of Crop Pathogens and Insects, Institute of Biotechnology, Zhejiang University, 310058 Hangzhou, China.
Zhejiang University-University of Edinburgh Institute, Zhejiang University, Hangzhou 314400, China.
Int J Biol Macromol. 2021 Jul 1;182:838-848. doi: 10.1016/j.ijbiomac.2021.04.051. Epub 2021 Apr 19.
In an environment with limited iron levels, sufficiently high intracellular iron concentrations are critical for bacterial survival. When iron levels are low, many bacteria including those of the Burkholderia cepacia group secrete chemically diverse siderophores to capture Fe. The synthesis of the two main siderophores, ornibactin and pyochelin, is regulated in an iron concentration dependent manner via the regulator protein Fur. In this study, we identified a novel Nonribosomal Peptide Synthetase (NRPS) cluster in strain R456 of Burkholderia seminalis, a member of the B. cepacia group. We show that the NRPS cluster not only allows the production of a so-far undescribed siderophore, but is also required for ornibactin and pyochelin production as it is a crucial component in the signaling pathway targeting the global iron regulating effector Fur which regulates siderophore production. Furthermore, the NRPS cluster is also involved in cell motility and biofilm formation, both of which are directly dependent on iron concentration in various bacteria. Interestingly, our data suggests that this newly discovered NRPS cluster which regulates siderophore iron metabolism in bacteria was obtained by horizontal gene transfer from algae.
在铁含量有限的环境中，足够高的细胞内铁浓度对细菌的生存至关重要。当铁水平较低时，包括伯克霍尔德氏菌属在内的许多细菌会分泌化学性质多样的铁载体来捕获 Fe。两种主要铁载体，即奥尼巴辛和焦脱镁叶绿酸的合成通过调节蛋白 Fur 以铁浓度依赖的方式进行调节。在这项研究中，我们在伯克霍尔德氏菌属 R456 菌株中鉴定出一个新的非核糖体肽合成酶 (NRPS) 簇，该菌株是伯克霍尔德氏菌属的成员。我们表明，NRPS 簇不仅允许产生一种迄今尚未描述的铁载体，而且还是 ornibactin 和 pyochelin 产生所必需的，因为它是靶向全局铁调节效应物 Fur 的信号通路的关键组成部分，Fur 调节铁载体的产生。此外，NRPS 簇还参与细胞运动和生物膜形成，这两者都直接依赖于各种细菌中的铁浓度。有趣的是，我们的数据表明，这种新发现的 NRPS 簇调节细菌中铁代谢的铁载体是通过从藻类获得的水平基因转移获得的。
