Exam 3: The Versatility of RNA

A GU wobble is an example of

Pseudoknots and tetraloops make up what part of RNA's structure?

You are characterizing the properties of a self-splicing ribozyme and obtain the following Results: in the presence of Mg²⁺, self-splicing occurs. However, in the absence of Mg²⁺, self-splicing does not occur. Which of the following hypotheses does this observation support?

Discuss why Francis Crick stated that "tRNA looks like Nature's attempt to make RNA do the job of a protein."

Draw the general structure of a nucleoside monophosphate. Show the sugar structure in detail and indicate the positions of attachment of the base and the phosphate. Also indicate the location of the 2′-OH group.

Which of the following is a similarity between the catalytic mechanisms of self-splicing introns and DNA polymerase?

How do eukaryotic RNA viruses differ from retroviruses?

For many years the pathway of gene expression from DNA to functional product via an RNA intermediate emphasized proteins as the ultimate goal. Discuss how this view has changed.

Base-paired stems in RNA

Compare and contrast the mode of action of "ribozymes" and "enzymes."

Explain how the discovery of ribozymes spawned the RNA World hypothesis.

Give examples of the structural and functional importance of the 2′-OH group on the ribose sugar of RNA.

You have discovered a small RNA involved in removal of a novel class of introns. Design an experiment to determine whether the small RNA functions as a catalytic RNA or RNP. Show sample positive results.

An A-minor motif is characterized by which of the following folding patterns?

Summarize the major types of secondary structure found in RNA. Include a labeled diagram.

What addition(s) would you need to make to the primary sequence in question 36 to allow pseudoknot formation?

You suspect that a tetraloop is critical for folding of a ribozyme into its active form. Describe an experiment to demonstrate whether the RNA folds into a similar tertiary structure when the tetraloop is deleted.

The most effective therapies known for the treatment of HIV infection are inhibitors of RNA-dependent DNA polymerases (also known as reverse transcriptases). Explain how this class of inhibitors would affect the virus's activities.

The study of tRNA structure has provided many important insights into RNA structural motifs. Discuss this statement.

You are investigating a ribosomal RNA (rRNA) gene with one large intron and two short exons. Show the results of R looping experiments performed with: a. final rRNA product and single-stranded DNA b. final rRNA and double-stranded DNA c. rRNA precursor and single-stranded DNA d. rRNA precursor and double-stranded DNA