Questions for Assigned Articles in Genetics

Dr. G. Kirchner

Gene Activators by Ptashne, Molecular Zippers by McKnight, Zinc Fingers by Rhodes and Klug.

Questions on Gene Activators

1. In general, how does Lambda repression work?

2. How is the Lambda repressor similar to and different from a transcription factor?

3. What kind of protein structure influences Lambda repressor activity?

4. What cooperativity of binding does Lambda repressor show, and how does this affect the efficiency of repression?

5. How does Gal regulation occur in yeast?

6. How and what kind of regulation does Gal 4 provide in yeast?

7. What kind of protein structure influences Gal 4 activity?

Questions on Molecular Zippers

1. What are housekeeping genes?

2. Describe how enhancers and silencers may work.

3. What is meant by a structural motif?

4. What does C/EBP stand for and how was it discovered?

5. What was the 60 amino acid sequence found to be like?

6. Why are they called leucine zippers?

7. What part of the zipper binds DNA and what amino acids are involved?

8. What are homodimers and heterodimers?

9. Are zippered genes conserved?

10. What is an asymmetric dyad motif, and what does it have to do with leucine zippers?

Questions on Zinc Fingers

1. What serendipitous event led to the discovery of the Zinc Finger TFIIIA?

2. How many bases does TFIIIA attach to and how does this compare with the "footprint" of bacterial regulatory proteins?

3. Describe the structure of the TFIIIA Zinc Finger.

4. How much DNA appears to be devoted to Zinc Fingers in humans?

5. How many fingers can a Zinc Finger have, and how many must it have to be functional?

6. What structural aspects seem to be necessary for the Zinc Finger structure?

7. How do scientists propose that Zinc Fingers evolve?

8. How do hormone receptors work?

9. What is a half site in the DNA?

10. What do Zinc Fingers have to do with Wilm's Tumor?  What do they have to do with estrogen and androgen receptors in humans?