Question

A mutation in E. coli results in the loss of both restriction endonucleases and modification enzymes. Would you expect any difference in the frequency of gene transfer via transduction FROM Salmonella INTO this E. coli strain?

Yes--the loss of the modification enzymes would leave the recipient E. coli unable to tag its own DNA as "self," leaving the viral DNA untagged and recognizable as "foreign." and targeted for destruction. This would lead to higher rates of successful transduction.

Yes--the loss of the restriction endonucleases would leave the recipient E. coli unable to break down "invading" viral DNA from the transducing phage, AND the loss of the modification enzymes would leave the recipient E. coli unable to tag its own DNA as "self," lea ing the viral DNA untagged and recognizable as

"foreign," and targeted for destruction. Together, these would lead to higher rates of successful transduction.

• No-transduction efficiency isn't affected by either restriction endonucleases or modification enzymes, so there'd be no effect on the overall rate.

No-since the Salmonella strain is normal, the rate of production of transducing virus particles would still be the same, resulting in the same frequency of gene

Answer 1

Loss of restriction endonucleases and modification enzymes in E. coli would lead to increased rates of successful gene transfer via transduction, as the cell's normal defense mechanisms against foreign DNA are compromised.

Step-by-step explanation:

A mutation in E. coli that results in the loss of both restriction endonucleases and modification enzymes would indeed affect the frequency of gene transfer via transduction from Salmonella into E. coli.

Without these enzymes, the recipient E. coli cannot effectively protect itself against foreign DNA from the transducing phage, leading to a higher likelihood of the foreign DNA being successfully incorporated into the E. coli genome. The loss of restriction endonucleases means that the E. coli cannot cut up the invading viral DNA, while the absence of modification enzymes prevents it from marking its own DNA and thereby differentiates it from the foreign DNA that could potentially be destroyed by the cell's defense mechanisms. Thus, together, both losses facilitate increased rates of successful transduction.