Operon

An operon is a group of genes including an operator, a common promoter, and one or more structural genes that are controlled as a unit to produce messenger RNA (mRNA). The mRNA is encoded by one or more of the structural genes in the operon.\nOperons occur primarily in prokaryotes and nematodes. They allow cells to respond to their environment. \nThey were first described by François Jacob and Jacques Monod in 1961.

The operon as a unit of transcription

An operon is a unit of transcription consisting of one or more structural genes, and two associated segments of DNA: \n* an operator (the switch)\n* a promoter (a binding site for the transcription enzyme). The switch of an operon (that is, the "operator") is turned on unless a specific substance is bound to the operator. This substance is therefore called a repressor. In summary:\n* The "operator" is a DNA binding site for a repressor;\n* transcription of the structural genes takes place unless a repressor is bound to the operator.

See also

\n*gene regulatory network\n*Lac operon Category:Gene expression