The operon is regulated by Lac repressor, the product of the lacI gene, which is transcribed from its own promoter (PI). The repressor inhibits transcription by binding to the lac operator (O).

The answer lies in regulating the operon. As trp levels increase ... Furthermore, the ability of E. coli to switch gene expression on and off under different environmental conditions is an ...

He wanted the DNA to contain the genetic information encoding most of the functions of SV40, all of the functions of the E. coli galactose (gal) operon, and the minimal parts of bacteriophage lambda ...