A newly identified bacterial strain needs melrose as a growthfactor. To synthesize melrose these bacteria use three enzymes thatare encoded by the genes melA, melB and melC in the mel operon. Theexpression of these three genes is controlled by a regulatoryprotein MelR. Melrose binds to MelR, and it changes the ability ofMelR to bind to the regulatory region of the mel operon. The melgenes are expressed only in the absence of melrose. The regulatorMelR, only in the absence of melrose, can bind at the regulatoryregion of mel operon. Answer the following questions and provide anexplanation for each answer
1. Is the mel operon inducible or repressible?
2. Is the MelR a positive or negative regulator?
3. Predict the expression of the mel operon in the followingthree melR mutants melR1, melR2 and melR3. Choose an answer asregulated or constitutive or no expression, including anexplanation.
i. In a melR1 mutant, MelR has lost the ability to bind tomelrose.
ii. In a melR2 mutant, MelR cannot bind to the regulatory regionirrespective of the presence or absence of melrose.
iii. In a melR3 mutant, MelR binds to the regulatory regionirrespective of the presence or absence of melrose.
