Repressor Proteins Do Not __________________

Question

Repressor proteins do not __________________.  
A) prevent binding of RNA polymerase to DNA
B) cause the DNA regions that contain the operator to twist or loop
C) inactivate operon genes when their products are not required
D) bind to sets of operators
E) increase transcription rates

Accepted Answer

Repressor proteins are negative regulators of gene expression, meaning they reduce or prevent transcription. They do this by binding to specific sequences of DNA called operators, which are typically located near or within the promoter region of a gene. Binding of the repressor protein to the operator can prevent binding of RNA polymerase to the promoter region, or cause the DNA to twist or loop in a way that prevents transcription. Thus, options A, B, C, and D correctly describe the actions of repressor proteins, while option E is incorrect.