原核增强子样序列3A的克隆及其结构与功能的研究

Cloning and Structure-function of Prokaryotic Enhancer-like Sequence 3A

从大肠杆菌 C60 0株染色体基因组中筛选到一个原核增强子样序列 3A,其正、反向增强活性分别能提高 β-半乳糖苷酶活性 7.1 1和 2 .93倍 .采用体内转录 ,RNA斑点印迹杂交的方法 ,证明3A序列对于基因表达的调控发生在转录水平上 . 3A功能区的研究表明 ,3A增强活性主要位于距其正向克隆 5′端 (增强活性较强的方向称为正向 ,反之为反向 ) 30 0～ 540 bp,长约 2 4 0 bp的区段内 ,并证明

A prokaryotic enhancer\|like sequence 3A,was screened from the genome of Escherichia coli strain C600 and its enhancement effect was analyzed.Its positive and negative enhancement activities were about 7 11 times and 2\^93 times respectively by increasing the expression of β\|galactosidase gene.By RNA dot hybrid assay,the enhancer\|like sequence 3A enhanced the expression of the reporter gene at the transcription level.The end\|deletion assay showed that the enhancing function region of sequence 3A was about 240 bp between 300 bp and 540 bp area at the 5′ end of the sequence and the function region consisted of at least two enhancing sites.