The lac operon consists of one regulatory gene and three structural gene (z, y and a) The i gene codes for the repressor of the lac If repressor protein binds to operator region of operon, it prevents RNA polymerase from transcribing the operon. Whereas, in presence of lactose (inducer) the repressor become inactivated due to interaction with inducer.
This allow RNA polymerase access to promoter and transcription proceeds. Regulation of lac operon is negative, it can be visualised as regulation of enzymes synthesis by its substrate. Regulation of lac operon by repressor is referred to as negative regulation
Explain the role of regulatory gene in a lac operon Why is regulation of lac operon called negative regulation?
Answers
Rajendra
The lac operon consists of one regulatory gene and three structural gene (z, y and a) The i gene codes for the repressor of the lac If repressor protein binds to operator region of operon, it prevents RNA polymerase from transcribing the operon. Whereas, in presence of lactose (inducer) the repressor become inactivated due to interaction with inducer.
This allow RNA polymerase access to promoter and transcription proceeds. Regulation of lac operon is negative, it can be visualised as regulation of enzymes synthesis by its substrate. Regulation of lac operon by repressor is referred to as negative regulation