Chapter 14, Problem 2AL

Describe the phenotype of the following E. coli mutants when grown in two different media: glucose only and lactose only. Explain the reasoning behind your answer.

1. a. A strain with a mutation in the gene encoding the lac repressor; the mutant repressor cannot bind allolactose.
2. b. A strain with a mutation in the gene encoding CAP; the mutant form of CAP binds but cannot release cAMP.
3. c. A strain in which the Shine-Dalgarno sequence has been deleted from the gene encoding adenyl cyclase.