Colicin-Mediated Transport of DNA through the Iron Transporter FepA.
Colicin-Mediated Transport of DNA through the Iron Transporter FepA.
复制标题
大肠杆菌素介导的 DNA 通过铁转运蛋白 FepA 的转运。
DOI：
10.1128/mbio.01787-21
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发表时间：
2021-10-26
期刊：
影响因子：
6.4
通讯作者：
Kleanthous C
中科院分区：
文献类型：
--
作者：
Cohen-Khait R;Harmalkar A;Pham P;Webby MN;Housden NG;Elliston E;Hopper JTS;Mohammed S;Robinson CV;Gray JJ;Kleanthous C
大肠杆菌素是由大肠杆菌部署以消除竞争菌株的蛋白质抗生素。大肠杆菌素经常利用外膜（OM）营养转运蛋白穿透选择性渗透细菌细胞包膜。在这里，通过应用活细胞荧光成像，我们能够监测成孔毒素大肠杆菌素B（ColB）进入E。并将其定位在周质中。我们进一步证明了与ColB偶联的单链DNA也可以被运输到周质，强调可以利用大肠杆菌素的进口途径将大的货物分子运送到细菌中。此外，我们的特征的分子机制的ColB协会与OM受体FepA通过应用光活化交联，质谱和结构建模的组合。我们表明，复杂的形成是一致的大肠杆菌素的大规模构象变化。此后，ColB通过FepA的主动转运涉及大肠杆菌素取代通常封闭该铁转运蛋白的塞结构域的N-末端一半。
Colicins are protein antibiotics deployed by Escherichia coli to eliminate competing strains. Colicins frequently exploit outer membrane (OM) nutrient transporters to penetrate the selectively permeable bacterial cell envelope. Here, by applying live-cell fluorescence imaging, we were able to monitor the entry of the pore-forming toxin colicin B (ColB) into E. coli and localize it within the periplasm. We further demonstrate that single-stranded DNA coupled to ColB can also be transported to the periplasm, emphasizing that the import routes of colicins can be exploited to carry large cargo molecules into bacteria. Moreover, we characterize the molecular mechanism of ColB association with its OM receptor FepA by applying a combination of photoactivated cross-linking, mass spectrometry, and structural modeling. We demonstrate that complex formation is coincident with large-scale conformational changes in the colicin. Thereafter, active transport of ColB through FepA involves the colicin taking the place of the N-terminal half of the plug domain that normally occludes this iron transporter.