Question

Describe the effect of amanitin on the maximum elongation rate for the wild-type and modified RNA polymerases. Determine the ratio of the average maximum elongation rate for the modified RNA polymerase compared to the wild strain RNA polymerase in Figure 1

Answer 1

Answer:

Average max. elongation rate = modified RNA pol./ wild type RNA pol = 2/12 = 0.166 nucleotides per sec.

Explanation:

After treating the wild type and experimental RNA with amanitin solution, the amanitin actively binds to the active site of wild type RNA polymerase, inhibiting addition of nucleotides and also it interferes with the motility of RNA pol. along the DNA template, due to which their is a sharp decline in maximum elongation rate of mRNA. In case of experimental RNA polymerase, due to single base substitution the experimental strain is already having very low elongation rate, but binding of amanitin causes constraint on the motility of RNA polymerase through the DNA template, thereby decreasing the elongation rate. Average max. elongation rate = modified RNA pol./ wild type RNA pol = 2/12 = 0.166 nucleotides per sec.