Genetic regulation in bacteria can involve alterations in RNA secondary structure.What phenomenon occurs in the trp operon that involves such alterations?
A)polyadenylation of the 3' end of the mRNAs
B)transcription
C)intron processing
D)attenuation
E)capping

Question

Quizplus · Accepted Answer

The phenomenon that occurs in the trp operon that involves alterations in RNA secondary structure is called attenuation. Attenuation is a regulatory mechanism in prokaryotes where transcription of a gene is terminated prematurely due to the formation of RNA secondary structures in the 5’ untranslated region (UTR). The trp operon contains a gene cluster that codes for the enzymes required for biosynthesis of the amino acid tryptophan. In the presence of tryptophan, the trp operon is repressed, and transcription is attenuated. The attenuation mechanism involves the formation of two alternative RNA secondary structures in the leader sequence of the mRNA, which determines whether or not transcription proceeds.

Genetic Regulation in Bacteria Can Involve Alterations in RNA Secondary