6.2 Prokaryotic Promoter Promoter:RNA polymerase binding site
6.2 Prokaryotic Promoter Promoter: RNA polymerase binding site
nitrocellulose filter-binding studies 硝化纤维滤膜结合实验 Double-stranded DNA Protein Protein-DNA complex Q00909o0 Filtrate
nitrocellulose filter-binding studies 硝化纤维滤膜结合实验
Binding of RNA Polymerase to Promoters core core core To measure the dissociation labeled DNA excess unlabeled DNA rate(分解率)ofthe polymerase-DNA complex core core core 100 the polymerase holoenzyme Holoenzyme binds much more tightly to the T7 DNA than does the 10 core enzyme. theo-factor can promote Core 0 tight binding,at least to 0 certain DNA sites. 0 20 40 60 Figure6.5Time(minl】
Binding of RNA Polymerase to Promoters core s + core s + core s core + core + core labeled DNA excess unlabeled DNA the polymerase holoenzyme binds much more tightly to the T7 DNA than does the core enzyme. theσ-factor can promote tight binding, at least to certain DNA sites. To measure the dissociation rate（分解率） of the polymerase-DNA complex
To measure the dissociation of loosest bound polymerase core core core To measure the dissociation unlabeled DNA excess labeled DNA of the first (and loosest bound)polymerase core core core a newly dissociated polymerase would be available to bind to the free labeled DNA and thereby cause it to bind to the filter. This assay revealed that the holoenzyme,as well as the core, had loose binding sites on the DNA. How to interpret the results?
To measure the dissociation of loosest bound polymerase a newly dissociated polymerase would be available to bind to the free labeled DNA and thereby cause it to bind to the filter. This assay revealed that the holoenzyme, as well as the core, had loose binding sites on the DNA. core s + core s + core s core + core + core unlabeled DNA excess labeled DNA How to interpret the results? To measure the dissociation of the first (and loosest bound) polymerase
CTight binding site promoter Holoenzyme has two kinds of binding sites on T7 DNA the rest of the DNA Core polymerase
Holoenzyme has two kinds of binding sites on T7 DNA Tight binding site Loose binding site Core polymerase promoter the rest of the DNA