Summary:
- Regulation of transcription in prokaryotes typically involves operons.
- An operon is a region of DNA that consists of one or more genes that encode the proteins needed for a specific function.
- A well-known example of operon regulation involves the lac operon in E. coli bacteria.
- The Lac operon consists of a promoter, an operator, and three genes.
- The genes are expressed only in the presence of lactose, the sugar found in milk.
- When lactose is absent, a repressor protein binds to the operator.
- This blocks the binding of RNA polymerase to the promoter.