See Hint In E. coli, eight enzymatic steps are involved in the biosynthesis of a
ID: 257591 • Letter: S
Question
See Hint In E. coli, eight enzymatic steps are involved in the biosynthesis of arginine from glutamate. The synthesis of the required enzymesis subject to control by the ArgD protein, which, on its own, binds weakly to a regulatory sequence just downstream of the promoter regions for these genes. Upon the addition of excess arginine to the growth medium, the respective mRNA molecules are no longer produced. What is the likely role of arginine in the control of these genes? Choose one: A. operator B. inducer C. repressor D. activator E. corepressor 23/23 pre-paid mailing ia pdExplanation / Answer
The correct answer is Corepressor. Arginine operon is a classical example of negatibe regulation operon and whenever the amount of arginine is more than required it will result in halting of operon and the respective mRNA will not be produced.