In: Biology
Which of the following genes of the Lac operon encode cis-acting regulatory elements?
Lacy
Lacl
None of these answers is correct
LacA
Lacz
Ans :-) option c. None of the answer is correct.
Cis acting genes are region of non coding dna which regulate the transcription of neighbouring genes. They regulate the gene expression by binding to the transcription factors. The most charaterised example of cis regulatory elements are promoters and enhancers. Operators are cis regulatory elements in prokaryotes and some eukaryotes that exist within operons. They can bind with repressors to affect transcription.
The regulatory gene LacI produces an mRNA that produces a lac repressor protein. This protein can bind to the operator of lac operon.
LacZ is encode for beta galactosidase which cleaves lactose into glucose and galactose. Lac Y encode for permease which increases permeability of cell for lactose. Lac A encode for transacetylase.