Difference between revisions of "Part:BBa K4673026"

Revision as of 15:45, 9 October 2023

LacI is a regulated repressor protein

One of the major trans-regulators of the lac operon is encoded by lacI, and it is able to form a homotetrameric repressor by assembling four identical molecules of lacI proteins together.

The lac operon comprises three distinct genes: lacZ, lacY, and lacA. The roles of the genes within the lac operon facilitates the cell's utilization of lactose. For instance, lacZ is able to encode an enzyme responsible for breaking down lactose into individual monosaccharides that can be fed into glycolysis. Similarly, lacY is responsible for encoding a transporter protein embedded in the cell membrane, aiding in the import of lactose into the cell. Beyond the three genes, the lac operon also encompasses a number of regulatory DNA sequences. These specific regions of DNA serve as binding sites for regulatory proteins, controlling the transcription process of the operon.

In addition, the Lac operon of the E. coli contains genes involved in lactose metabolism, playing an important role in the IPTG induction mechanism. The expression of lac operon occurs only when lactose is present and glucose is absent. This regulatory process is controlled by the two regulators, the lac repressor(lacI) and catabolite activator protein(CAP), turning the operon "on" and "off" in response to lactose and glucose levels. The structure of the lac operon comprises the lac operator, which is a negative regulatory overlap with the promoter. Therefore, when lac repressor binds to lac operator, RNA polymerase cannot bind to the promoter and start transcription.

Sequence and Features