lac operon


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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 ?
His description of control mechanisms in the lac operon shows the complexity of that system, but one might wonder why he did not instead describe replication and its control mechanisms, which are just as complex and would have tied in better with the rest of the chapter.
The molecular mechanism for blue/white screening is based on genetic engineering of the lac operon in the Escherichia coli laboratory strain serving as a host cell, combined with a subunit complementation achieved with the cloning vector.
In 1988 molecular biologist John Cairns and his colleagues at the Harvard School of Public Health observed induced mutations of various elements of the lac operon changes in Escherichia coli bacteria.