Name
 

1. What would happen to the plasmid copy number of the F plasmid and ColE1 plasmid if you added the following antibiotics to an E. coli culture (the strain is sensitive to the antibiotics, but the question is not what happens if the culture dies or stops growing - it's how does the antibiotic affect the plasmid). In a sentence explain your answer. Hint - at one time one of these treatments was used to aid in plasmid extraction.

A. ColE1 - Rifampin

B. F plasmid - Rifampin

C. ColE1 - Chloramphenicol

D. F plasmid - Chloramphenicol

2. For the F plasmid describe what would happen to copy number of the plasmids if the binding site for RepE at the promoter for repE and [not the ori] was mutated to possess lower affinity for the protein.

3. Which of the following loci are necessarily cis-active? (Check all boxes that are correct.)
copA/incC of F
RNA-II of ColE1 
rop of ColE1 
oriV of F

4. You want to construct a plasmid with a variable copy number (e.g., low copy number when you clone your favorite gene, but increased copy number when you attempt maximal expression of your favorite gene). How would you construct such a plasmid? Just a few sentences please.

5.  I used to teach that the iteron motif of the F plasmid acted by titrating or sopping the RepE protein and keeping it from acting as the DnaA equivalent at the F plasmid origin of replication.  The current model in the book called coupling is different.  Briefly summarize the experimental data described in the text that support the coupling and show that the titration model is not correct.