What is the likely effect of each of the following mutations of the trpL region on attenuation control of trp operon gene transcription? Explain your reasoning. The start (AUG) codon of the trpL polypeptide is deleted.

Key Concepts

Attenuation in Gene Regulation

Attenuation is a regulatory mechanism in prokaryotes, particularly in the trp operon, that controls gene expression based on the availability of tryptophan. It involves the formation of specific RNA structures during transcription that can either promote or inhibit the continuation of transcription, depending on the cellular conditions.

trp Operon Structure

The trp operon is a cluster of genes in bacteria that encode enzymes for tryptophan biosynthesis. It includes regulatory regions such as the trpL leader sequence, which plays a crucial role in attenuation by sensing tryptophan levels and influencing the formation of transcriptional terminators or antiterminators.

Impact of Mutations on Protein Function

Mutations, such as the deletion of the start codon (AUG) in the trpL region, can significantly affect protein synthesis. In this case, the absence of the start codon would prevent the translation of the trpL peptide, disrupting the feedback mechanism that regulates the trp operon and potentially leading to unregulated transcription of tryptophan biosynthetic genes.