operon

a segment of DNA containing adjacent genes including structural genes and an operator gene and a regulatory gene

• deoxyribonucleic acid, desoxyribonucleic acid, DNA — a nucleic acid found in the nucleus of a cell and consisting of a polymer formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information

• operator gene — a gene that activates the production of messenger RNA by adjacent structural genes
• regulatory gene, regulator gene — a gene that produces a repressor substance that inhibits an operator gene