A series of experiments is being conducted to determine the structure and function of different types of bacterial RNA. Cultures of Staphylococcus aureus are exposed to chemicals that lyse the bacterial cells, and the RNA molecules are then extracted. A specific RNA consisting of 90 nucleotides is purified for further analysis. It is found to contain high amounts of chemically modified bases such as dihydrouridine, pseudouridine, and ribothymidine, and its secondary structure arises from base pairing within the chain. Which of the following is the most likely composition of the 3'-end of this molecule?

Question

A series of experiments is being conducted to determine the structure and function of different types of bacterial RNA.  Cultures of Staphylococcus aureus are exposed to chemicals that lyse the bacterial cells, and the RNA molecules are then extracted.  A specific RNA consisting of 90 nucleotides is purified for further analysis.  It is found to contain high amounts of chemically modified bases such as dihydrouridine, pseudouridine, and ribothymidine, and its secondary structure arises from base pairing within the chain.  Which of the following is the most likely composition of the 3'-end of this molecule?

Quizplus · Accepted Answer

Eductional Objective: Transfer RNA (tRNA)  is a small, noncoding form of RNA that contains chemically modified bases (eg, dihydrouridine, ribothymidine, pseudouridine).  tRNA has a CCA sequence at its 3'-end that is used as a recognition sequence by proteins.  The 3' terminal hydroxyl group of the CCA tail serves as the amino acid binding site.

A Series of Experiments Is Being Conducted to Determine the Structure