Suppose You Have Engineered a Plasmid Vector in Order to Produce

Suppose you have engineered a plasmid vector in order to produce a functional animal protein in E. coli. But the product you collect, while it has the correct amino acid sequence, is in fact nonfunctional. What might you try that would have a greater chance of success?

A) a eukaryotic expression vector that has sequences for regulating transcription
B) using a host other than E. coli that does not have the same codon bias
C) a eukaryotic expression vector that includes sequences for controlling posttranslational effects
D) treatment of the posttranslation proteins to add signal sequences
E) using yeast artificial chromosomes that can hold longer sequences