摘要
构建了插入λ阻抑蛋白（Ｒｅｐ）的操纵基因（ＯＲ）和ＢｇｌⅡ识别位点的ＰＢＲ３２２重组质粒。阻抑蛋白与该质粒的相互作用可用ＢｇｌⅡ对它的水解作用引起的ＥＢ荧光变化来研究。在Ｅ．ｃｏｌｉ中表达的Ｒｅｐ表现了与该重组质粒结合的活力。核苷酸序列具精确二重对称性的ＯＲ（ＯＲｃｏｎｓ）对Ｒｅｐ的亲和力比天然的ＯＲ１小。
A recombinant PBR322 plasmid with inserts of operator sequence for lambda repressor and Bgl Ⅱ site was constructed. The interaction of lambda repressor to its operator within the recombinant plasmid was evaluated by fluorescence changes of intercalated ethidium bromide produced by Bgl Ⅱ digestion. The crude preperation of lambda repressor expressed in E. Coli showed a significant binding activity to its operator. According to the fluorescence changes, the consensus operator with an exact twofold symmatery sequence showed lower affinity to Rep than natural OR1.
关键词
DNA
蛋白
荧光
测定
Lambda repressor-operator binding
Protein-DNA binding
Fluorescence assay
