Bacterial repressor proteins that bind to the LAC OPERON and thereby prevent the synthesis of proteins involved in catabolism of LACTOSE. When lactose levels are high lac repressors undergo an allosteric change that causes their release from the DNA and the resumption of lac operon transcription.

Synonyms: 0, LacI Proteins, Repressor, Lac, Repressors, Lac, Lac Repressors, Proteins, LacI, Lac Repressor