Enhanced production of Shiga toxin 1 in enterohaemorrhagic Escherichia coli by oxygen
Enhanced production of Shiga toxin 1 in enterohaemorrhagic Escherichia coli by oxygen
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氧气增强肠出血性大肠杆菌中志贺毒素 1 的产生
DOI：
10.1099/mic.0.001122
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发表时间：
2021
期刊：
影响因子：
1.5
通讯作者：
Hamabata Takashi
中科院分区：
文献类型：
--
作者：
Shimizu Takeshi;Onuki Manami;Suzuki Shin;Hirai Shinichiro;Yokoyama Eiji;Matsumoto Akio;Hamabata Takashi
肠出血性大肠杆菌（EHEC）产生志贺毒素1 （Stx1）和志贺毒素2 （Stx2）。虽然stx1和stx2存在于stx编码噬菌体（Stx-phages）的后期操纵子中，但stx1主要是从stx1启动子（PStx1）转录而来，PStx1是stx1上游转录调节因子Fur（铁摄取调节因子）的功能操作子结合位点（Fur box）。在本研究中，我们发现肠出血性大肠杆菌产生Stx1受氧浓度的影响。在氧气存在下增加Stx1的产生依赖于Fur，这是一种Fe2+响应转录因子。微氧条件下细胞内的Fe2+池比厌氧条件下低，表明较低的Fe2+可用性导致Fe2+-Fur的形成减少，与pstx1区域的DNA结合减少，Stx1的产生增加。
EnterohaemorrhagicEscherichia coli(EHEC) produces Shiga toxin 1 (Stx1) and Shiga toxin 2 (Stx2). Althoughstx1andstx2were found within the late operons of the Stx-encoding phages (Stx-phages),stx1could mainly be transcribed from thestx1promoter (PStx1), which represents the functional operator-binding site (Fur box) for the transcriptional regulator Fur (ferric uptake regulator), upstream ofstx1. In this study, we found that the production of Stx1 by EHEC was affected by oxygen concentration. Increased Stx1 production in the presence of oxygen is dependent on Fur, which is an Fe2+-responsive transcription factor. The intracellular Fe2+pool was lower under microaerobic conditions than under anaerobic conditions, suggesting that lower Fe2+availability drove the formation of less Fe2+-Fur, less DNA binding to thePStx1region, and an increase in Stx1 production.