Eukaryotic genes coding for proteins usually have introns. The production of recombinant eukaryotic proteins (insulin, for example) in bacteria does not necessarily pose a problem because
A) bacteria possess the necessary enzymes to correctly process the primary transcript containing intron sequences.
B) a cDNA copy of the mRNA can be cloned and expressed.
C) the protein synthetic machinery of the bacteria will only translate the exon portions of the resulting RNA.
D) the translation of intron regions will not alter the activity of the protein if they are removed by proteolytic processing.

Question

Quizplus · Accepted Answer

Cloning the cDNA copy of the mRNA will eliminate the introns, allowing for the production of a functional protein in bacteria. Bacteria do not have the necessary machinery to correctly process and remove introns from the primary transcript, and if the introns were translated it could alter the protein function. The protein synthetic machinery of the bacteria will translate the entire mRNA sequence, including the introns, if they are present. The removal of introns by proteolytic processing after translation is not a viable option to produce functional eukaryotic proteins in bacteria.

Eukaryotic Genes Coding for Proteins Usually Have Introns