Which of the following best lists the correct order of the steps taken to produce human insulin in E.coli in the 1970s?
I. Each insulin chain was cloned into an expression vector as a continuation of the lacZ reading fra resulting in a fusion protein for each chain.
II. Disulfide bonds were induced to form between the cysteine residues of the purified insulin A a chains.
III. Both human insulin genes were reverse translated to create synthetic genes.
IV. EcoRI and BamHI restriction sites were added to the ends of the DNA to facilitate directional cloning of each into a separate plasmid vector.
A) III, I, II, IV
B) I, II, III, IV
C) I, III, IV, II
D) III, IV, I, II
E) IV, III, I, II

Question

Quizplus · Accepted Answer

The correct order for producing human insulin in E.coli during the 1970s starts with reverse translating the human insulin genes to create synthetic genes (III), followed by adding restriction sites for cloning (IV), then cloning each insulin chain into an expression vector (I), and finally inducing the formation of disulfide bonds (II).

Which of the Following Best Lists the Correct Order of the Steps