In a Hypothetical Bacterial Operon, Genes A, C, and D

Short Answer

In a hypothetical bacterial operon, genes A, C, and D are expressed when "substance r" is present but not when it is absent.Mutations in gene A cause protein 1 not to be produced, but they only affect production of protein 1.Mutations in gene C cause protein 2 not to be produced.Mutations in gene D cause protein 3 not to be produced.Gene B, which has been shown to be near the other genes, does not code for a protein.Mutations in gene B cause genes A, C, and D to be expressed all the time regardless of the presence or absence of substance r.Gene E produces protein 4.Mutations in gene E (which is not near A, B, C, or D) cause genes A, C, and D to be expressed all the time regardless of the presence or absence of substance r.What is the role of gene B?