Question: Think about a strain of E. coli that has a mutation in the gene encoding the IIA protein of the phosphotransferase system.The transport of glucose is not affected by this mutation; the mutant IIA protein can be phosphorylated and the phosphate group is transferred to glucose just as it occurs in the wildtype strain. However, phosphorylation of the mutant IIA protein does not affect its interactions with LacY and adenylate cyclase;i.e. – the phosphorylated form of the mutant IIA protein interacts with LacY permease and adenylate cyclase in a manner identical to the unphosphorylated form of the wildtype IIA protein. How will the lac operon be expressed in this mutant strain of E. coli in the following conditions?
plus glucose, minus lactose:
plus glucose, plus lactose
minus glucose, minus lactose:
minus glucose, plus lactose: