The Key Laboratory of Industrial Biotechnology of Ministry of Education School of Biotechnology, Jiangnan University, 1800, Lihu Avenue, Wuxi, 214122, China.
National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, 1800, Lihu Avenue, Wuxi, 214122, China.
Chembiochem. 2020 Jul 16;21(14):2067-2072. doi: 10.1002/cbic.202000068. Epub 2020 Apr 9.
Transcription terminators play a role in terminating the progress of gene transcription, and are thus essential elements in the gene circuit. Terminators have two main functions: terminating gene transcription and improving the stability of gene transcripts during translation. We therefore considered the detailed characteristics of terminators in relation to their different roles in gene transcription and translation, including transcription shut-down degree (α) and upstream mRNA protection capacity (β), and apparent termination efficiency (η) reflecting the overall regulatory effect of the terminator. Based on a dual-reporter gene system, we constructed three terminator-probe plasmids to investigate each characteristic in Escherichia coli. According to multiple regression analysis, the transcription shut-down degree and the upstream mRNA protection capacity contributed almost equally to the apparent termination efficiency. Sequence analysis of 12 terminators demonstrated that the terminator sequence was dominated by GC bases, and that a high ratio of GC bases in the stem structure of terminators might be associated with a high degree of transcription shut-down. This comprehensive characterization of terminators furthers our understanding of the role of terminators in gene expression and provides a guide for synthetic terminator design.
转录终止子在终止基因转录的进程中发挥作用，因此是基因回路的重要组成部分。终止子有两个主要功能：终止基因转录和提高翻译过程中基因转录本的稳定性。因此，我们考虑了终止子在基因转录和翻译中的不同作用的详细特征，包括转录关闭程度（α）和上游 mRNA 保护能力（β），以及反映终止子整体调控效果的明显终止效率（η）。基于双报告基因系统，我们构建了三个终止子探针质粒，以研究大肠杆菌中的每个特征。根据多元回归分析，转录关闭程度和上游 mRNA 保护能力对明显终止效率的贡献几乎相等。对 12 个终止子的序列分析表明，终止子序列主要由 GC 碱基组成，终止子茎结构中 GC 碱基的高比例可能与转录关闭程度高有关。对终止子的全面表征加深了我们对终止子在基因表达中作用的理解，并为合成终止子设计提供了指导。
