Yoon Youngdae, Kang Yerin, Lee Woonwoo, Oh Ki-Cheol, Jang Geupil, Kim Bong-Gyu
Department of Environmental Health Science, Konkuk University, Seoul 05029, Republic of Korea.
Nakdong River Basin Environmental Office, Changwon 51439, Republic of Korea.
J Microbiol Biotechnol. 2018 Feb 28;28(2):323-329. doi: 10.4014/jmb.1710.10012.
In , the transcription of genes related to metal homeostasis is activated by the presence of target metals. The promoter regions of those genes can be fused with reporter genes to generate whole-cell bioreporters (WCBs); these organisms sense the presence of target metals through reporter gene expression. However, the limited number of available promoters for sensing domains restricts the number of WCB targets. In this study, we have demonstrated an alternative method to generate novel WCBs, based on the notion that since the sensing mechanisms of WCBs are related to metal transportation systems, their properties can be modulated by disrupting metal homeostasis. Mutant strains were generated by deleting the -operon genes , which encodes a zinc-export protein, and , which encodes a -operon regulatory protein, to investigate the effects on the metal-sensing properties of WCBs. Deletion of increased the sensitivity but abolished the selectivity of cadmium-sensing WCBs, whereas arsenic-sensing WCBs gained sensitivity toward cadmium. When was deleted, cadmium-sensing WCBs lost the ability to detect cadmium, and this was recovered by introducing exogenous . In addition, the metal-binding site of ZntR was genetically engineered to modulate metal selectivity. This study provides a valuable platform for the development of novel -based WCBs.
在[具体情况]中，与金属稳态相关的基因转录会因目标金属的存在而被激活。这些基因的启动子区域可与报告基因融合以产生全细胞生物传感器（WCBs）；这些生物体通过报告基因的表达来感知目标金属的存在。然而，用于传感结构域的可用启动子数量有限，限制了WCB的目标数量。在本研究中，我们展示了一种产生新型WCBs的替代方法，基于这样一种观念，即由于WCBs的传感机制与金属运输系统相关，它们的特性可通过破坏金属稳态来调节。通过缺失编码锌输出蛋白的 -操纵子基因 和编码 -操纵子调节蛋白的 来产生突变菌株，以研究对WCBs金属传感特性的影响。缺失 增加了镉传感WCBs的灵敏度，但消除了其选择性，而砷传感WCBs对镉获得了灵敏度。当 被缺失时，镉传感WCBs失去了检测镉的能力，通过引入外源 可恢复此能力。此外，对ZntR的金属结合位点进行基因工程改造以调节金属选择性。本研究为开发新型基于[具体内容]的WCBs提供了一个有价值的平台。
