The DNA sequence encoding the leader peptide of the trp operon was mutated as shown below. The wild-type and altered nucleotide is bolded for ease of identification

ATGAAAGCAATTTCCGTACTGAAAGGTTGGTGGCGCACTTCCTGA wild type leader peptide
coding sequence

ATGAAAGCAATTTCCGTACTGAAAGGTGGGTGGCGCACTTCCTGA mutant leader peptide
coding sequence

What change in the control of trp operon expression is most likely to occur in E. coli cells containing the mutant leader peptide coding sequence compared to wild type?

A. The Trp repressor will bind more tightly to the trp operon in the mutant cells.
B. The amount of attenuation will be reduced in the mutant.
C. Negative control of the trp operon will be increased in the mutant.
D. Open promoter complexes will form less often in the mutant.


B

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