Proteins which increase promoter activity when bound to control regions are called positive regulators, or activators. Proteins which decrease promoter activity when bound to control regions are called negative regulators, or repressors. Table 1, p.323, lists some genes controlled by positive regulators in E. coli . B. Control of transcription termination. Control of translation.
Translational repression is a regulatory circuit found in the operons encoding ribosomal proteins.
In this way, the bacterium strictly regulates the stoichiometry of rRNA, r-proteins, and ribosomes. Figure 3, p. 329 outlines critical points in the flow of genetic information from DNA to RNA to protein at which regulatory controls have been found to be exerted. The lac operon. Utilization of lactose by E. coli has been studied for decades as a model of genetic regulation of bacterial physiology, and the lac operon is known in more detail than any other operon.