Q12 - Regulation of the rut Operon by the RutR Repressor and Uracil
In Escherichia coli. the rutA - G gene cluster activates when pyrimidine is decomposed and used as a nitrogen source. The rutA - G genes constitute a single rut operon, and a single Prut promoter regulates the expression. The expression of the Prut promoter is regulated by a RutR repressor using uracil as an inducer.
Using the information and data, determine which of the statements are true or which are false.
A. As the concentration of uracil increases, the expression level of the rut operon decreases.
B. When a mutation occurs in the RutR repressor and the affinity for uracil is reduced, the expression level of the rut operon is reduced.
C. If a mutation occurs in the DNA binding domain of the RutR repressor and the affinity for the DNA sequence decreases, the expression level of the rut operon increases.
D. When a mutation occurs in the nucleotide sequence of the operator to which the RutR repressor in the Prut promoter binds, the expression level of the rut operon always becomes high.
Question reproduced from IBO 2020, Theoretical Exam 1, licensed under CC BY-NC-SA 4.0 - attributed to the International Biology Olympiad. Open the full exam PDF · Community solutions (unofficial)