Operon

An operon is a functional unit of DNA from prokaryotes and some eukaryotes consisting of promoter, operator (s) and a plurality of ( structural) genes which code for proteins with related functions typically. Depending on the different operon regulatory proteins can occur ( repressors or activators ) with the operators in interaction and thereby the transcription of the genes in the operon on or off. This depends on their interactions with formed or taken up by the cell substances ( ligands or effector ). Wherein the synthesis of the relevant mRNA ( messenger RNA ) is activated or inhibited, and thus indirectly also the translation of the encoded proteins.

All genes of an operon are controlled coordinated. The operon model of gene regulation was among others in 1960 by the French scientists François Jacob and Jacques Monod developed on the basis of the lac operon of E. coli and later enlarged. For her work in this area, they received the 1965 Nobel Prize in Physiology or Medicine.

Operon also play an important role as tools of genetic engineering. Any genes can be under the control of regulatory elements of an operon questions and can thus, for example, are specifically activated in the case of the lac operon by addition of the synthetic inducer IPTG (isopropyl- β -D -thiogalactopyranoside ).