lac operon

(redirected from Lac promoter)
Also found in: Encyclopedia.

Lac op·er·on

(lahk),
a collection of adjacent bacterial genes responsible for the entry and metabolism of lactose; contains the genes coding for three enzymes and is flanked by a repressor and a promoter region to control expression.

lac operon

A sequence of genes found in many bacteria that codes for the enzymes needed to break down lactose to glucose and galactose so that the sugars can be utilized. Studies on the lac operon have been important in genetic research. The lactose repressor protein controls the transcription of the lac operon.

lac operon

the genetic system of Escherichia coli that is required to metabolize lactose and on which the OPERON MODEL is based.

lac operon

the lactose operon, a nucleotide sequence in Escherichia coli that controls the synthesis of the enzyme β-galactosidase comprising binding sequence motifs for the cap protein, which activates transcription, the repressor protein, which inhibits transcription, and a region with which RNA polymerase interacts. The first, best studied and best understood model for gene regulation.
References in periodicals archive ?
coli cat gene under the control of the lac promoter, they found that CAT (chloramphenicol acetyltransferase) production was reduced by more than 90 percent in a mutant in which an open reading frame overlapped the cat coding sequence out-of-frame.
Effects of alterations in the translational control region on bacterial gene expression: Use of cat gene constructs transcribed from the lac promoter as a model system.
Based on the MDS[TM]42 strain, ScarabXpress T7lac contains a chromosomal copy of the T7 RNA polymerase gene expressed from a unique, tightly controlled lac promoter.