- A newly identified bacterial strain needs nedine as a growthfactor. To synthesize nedine these bacteria use three enzymes thatare encoded by the genes nedA, nedB andnedC in the ned operon. The expression of thesethree genes is controlled by a regulatory protein NedR. Nedinebinds to NedR, and it changes the ability of NedlR to bind to theregulatory region of the ned operon.
The ned genes are expressedonly in the absence of nedine. The regulator NedR, only when boundto nedine, can bind at the regulatory region of the nedoperon.
Answer all questions
- Draw the ned operon showing structural and regulatorygenes, the regulatory region including the promoter and terminator.Describe the role of each term in your drawing.
- Show the regulation model of the ned operon in theabsence of nedine. In your figures, include structural genes,regulatory region, NedR, transcription and translation. Describethe process how gene expression is turned ON or OFF in the absenceof nedine.
- Show the regulation model of the ned operon in thepresence of nedine. In your figures, include structural genes,regulatory region, NedR, nedine, transcription and translation.Describe the process of how gene expression is turned ON or OFF inthe presence of nedine.
