枯草芽孢杆菌中一种新型双向启动子的功能鉴定

Characterization of a novel bidirectional promoter in Bacillus subtilis

摘要:

本研究旨在通过转录组分析预测的方法，由地衣芽孢杆菌中筛选获得一种新型双向启动子，鉴定其启动强度。以已知强组成型启动子pShuttle-09为对照，检测其对克劳氏芽孢杆菌碱性蛋白酶基因的表达活性。成功构建了3种重组碱性蛋白酶表达载体及对应的工程菌株。在新型启动子pLA和其反向启动子pLB调控转录下，克劳氏芽孢杆菌碱性蛋白酶表达活性达到 164 U/mL和111 U/mL。结果表明，pLA的启动强度明显高于pShuttle-09和pLB，pLA启动子与pLB启动子均可表达碱性蛋白酶。从而为枯草芽孢杆菌表达系统中异源基因的表达提供一个新的方向，也为原核生物中共同表达两种基因提供了新的思路。

Abstract:

Based on the transcriptome analysis data of a Bacillus licheniformis, a novel bidirectional promoter was identified from the strain and its transcriptional strength was analyzed. The expression level of a Bacillus clausii derived alkaline protease gene driven by the bidirectional promoter was studied by using the known strong constitutive promoter pShuttle-09 as a control. Three recombinant expression vectors and the corresponding recombinant bacteria were constructed. Under the control of the new promoter pLA and its reverse promoter pLB, the alkaline protease expression level respectively reached 164 U/mL and 111 U/mL. The results indicated that the transcription strength of pLA was significantly higher than that of pShuttle-09 and pLB, and both the pLA and pLB promoters could initiate the expression of the alkaline protease. Thus, it provides a new expression element for the heterogenous genes in Bacillus sp. and a new idea for the co-expression of two genes in one prokaryotic strain.