Exhibit 13A This is a map of the pBR322 plasmid,numbers on the map refer to the base where the site is located.
Refer to Exhibit 13A.If a recombinant plasmid were obtained by inserting DNA into the EcoRV site,and the protein corresponding to the recombinant gene were expressed,which of the following statements would be false?
A) The protein will probably contain some extra amino acids on its N-terminal.
B) The plasmid will be resistant to ampicillin.
C) The plasmid will not be able to replicate autonomously.
D) The protein is not likely to be biologically active without some further treatment.
E) The question cannot be answered, since it is unlikely that the protein will be expressed at all, because there is no promoter for mRNA synthesis.

Question

Exhibit 13A This is a map of the pBR322 plasmid,numbers on the map refer to the base where the site is located.
 Refer to Exhibit 13A.If a recombinant plasmid were obtained by inserting DNA into the EcoRV site,and the protein corresponding to the recombinant gene were expressed,which of the following statements would be false?
A) The protein will probably contain some extra amino acids on its N-terminal. 
B) The plasmid will be resistant to ampicillin. 
C) The plasmid will not be able to replicate autonomously. 
D) The protein is not likely to be biologically active without some further treatment. 
E) The question cannot be answered, since it is unlikely that the protein will be expressed at all, because there is no promoter for mRNA synthesis.

Quizplus · Accepted Answer

The EcoRV site is located within the ori region of pBR322 plasmid, which is essential for the plasmid's ability to replicate autonomously. Insertion of DNA into this site will disrupt the ori function, and therefore, the plasmid will not be able to replicate autonomously. However, the protein expression may still occur from the recombinant plasmid, and it may or may not require some further treatment to become biologically active. The insertion of DNA into the EcoRV site will not affect the presence of the ampicillin resistance gene, so the plasmid will still be resistant to ampicillin. The N-terminal extension of the protein would only occur if the inserted DNA contains a translation initiation codon in the correct reading frame downstream of the EcoRV site, but it is not a guaranteed outcome. The question does not involve mRNA synthesis and promoter activity.

Exhibit 13A This Is a Map of the PBR322 Plasmid,numbers