operator gene - a gene that activates the production of messenger RNA by adjacent structural genes

regulator gene, regulatory gene - a gene that produces a repressor substance that inhibits an operator gene

deoxyribonucleic acid, desoxyribonucleic acid, DNA - (biochemistry) a long linear polymer found in the nucleus of a cell and formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information; "DNA is the king of molecules"