Question

The fur box of the E. coli fepCDG operon is

A. an effector binding sequence.

B. an operator sequence.

C. a regulatory sequence.

D. Two of the above.

E. All of the above.

Answer 1

Answer: FepCDG operon play an important role in iron uptake in E.coli. Fur box is a regulatory nucleotide sequence and called as operator. Fur protein is a transcriptional repressor that negatively regulates fepCDG operon. Fur protein is activated by an effector called as Fe2+. Upon activation, it binds to fur box and inhibits transcription of fepCDG genes. As the effector is binding to repressor protein not to the fur box sequence, option A is incorrect. Hence, the correct answer is D.