摘要
用PCR方法克隆了巴西固氮螺菌Yu62nifH的启动子片段,DNA序列分析表明菌株Yu62与标准菌株Sp7之间的DNA序列差异很小。利用启动子探针质粒载体pCB182,构建了3个不同的nifH::lacZ转录融合质粒,在大肠杆菌中分别测定肺炎克氏杆菌NifA对它们的转录激活作用。结果表明巴西固氮螺菌nifH启动子的转录是依赖于NifA的,缺失了上游激活序列的启动子不能被NifA激活转录,肺炎克氏杆菌NifA对其自身nifH及巴西固氮螺菌nifH启动子的转录激活作用并无很大差异。
In this study, nifH promoter region of Azospirillum brasilense Yu62 was cloned by PCR method. The nucleotide sequence displayed that the strain Yu62 was very closely related to the strain Sp7. Using promoter probe vector pCB182, three different nifH:: lacZ transcriptional fusion plasmids were constructed, (B-galactosidase activity was detected in vivo in Escherichia coli, in the presence or absence of NifA of Kleb-siella pneumoniae, respectively, the results demonstrated that; 1. The transcription of nifH promoter of A. brasilense was NifA-dependent; 2. The nifH promoter with deletion of upstraem activator sequence (UAS) could not be activated even in the presence of NifA;3. There was no obvious difference of NifA-mediated transcriptional activation of nifH promoter between K. pneumoniae and A. brasilense.
出处
《生物工程学报》
CAS
CSCD
北大核心
1995年第3期205-210,共6页
Chinese Journal of Biotechnology
基金
863计划资助项目
