In vitro Transcription of the lac Operon Genes
This extract was created in the absence of an abstract.
Excerpt
It has been shown recently that the expression of operons subject to catabolite repression requires 3′,5′-cyclic AMP (Perlman and Pastan, 1968; Ullmann and Monod, 1968) and a protein factor, CAP (Zubay, Schwartz, and Beckwith, 1970; Emmer, deCrombrugghe, Pastan, and Perlman, 1970). The protein factor has been partially purified from E. coli extracts with the use of mutants missing this factor. These mutants are incapable of growing on a variety of carbon sources (Schwartz and Beckwith, 1970).
The lac operon, which is subject to catabolite repression, has been used as a tool to further analyze the mechanisms involved. In an in vitro system which can synthesize β-galactosidase starting from ϕ80iλdlac DNA, there is a strong stimulation of β-galactosidase synthesis dependent both on cyclic AMP and the factor (Zubay et al., 1970).
There is evidence that catabolite repression is an effect on initiation of transcription of sensitive operons. One indication that it...
