文献类型：期刊文献

英文题名：Establishment of a low-dosage-IPTG inducible expression system construction method in Escherichia coli

作者：Zhao, Ming[1];Tao, Xin-Yi[1];Wang, Feng-Qing[1];Ren, Yu-Hong[1];Wei, Dong-Zhi[1]

机构：[1]East China Univ Sci & Technol, Newworld Inst Biotechnol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2018

卷号：58

期号：9

起止页码：806

外文期刊名：JOURNAL OF BASIC MICROBIOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000443394500009)】；

基金：National Natural Science Foundation of China, Grant number: 21776075

语种：英文

外文关键词：gene expression system; lac operon; low-dosage-IPTG; synthetic promoter library

摘要：The lac operon is a delicate inducible gene expression element in bacteria. To efficiently induce gene expression, a sufficient dosage of an inducer, usually that of 500-1000 mu M isopropyl -D-1-thiogalactopyranoside (IPTG), is required to keep repressor LacI from its binding sites, which is a heavy cost burden in low-value-added products. So we propose a strategy to reduce the required dosage of IPTG by restricting LacI expression. To test this strategy, we employed a reconstructed IPTG inducible expression system based on lac operon, Promoter(lacO)-target gene-PtacL-lacI, where a modified promoter, Ptac, with a random synthetic library (PtacL) to instead of PlacI to optimize LacI expression in Escherichia coli. Finally, the PtacL mutant, PtacL4, which could maintain the same repression effect as the original PlacI while reducing the required dosage of IPTG from 500 to 20 mu M, was selected. This method is simple and efficient and can be of a good reference point for attempts to reduce inducer concentration in the IPTG or similar inducible expression systems.