Question

A biology 207 student sub cloned the mRFP1 gene from pkan -mRFP1 into pUC19-207 using a double digest. They used competent, prototrophic DH5aE. coli cells in their transformation protocol and plated the transformation reaction onto minimal medium that contained additional supplements to help them screen and select for their desired transformants. AIl experimental procedures were followed such as incubation times etc. Note that mRFP1 encodes for a protein that fluoresces red. Diagrams of the plasmids are below, use them to answer the questions that follow on this page. PtO8 1715 Bsa l 1766

Answer 1

Answer: Option E is correct.

Explanation:
mRFP1 can be subcloned into pUC19 from pKan using SacI and Eco Ri restriction enzyme sites.
mRFP1 has 1 Not I site at 1 kb upstream to its stop site.
pUC19 has two Not I sites.

In the recombinant plasmid,
First Not I site will be upstream to mRFP1 start site. So, Not I digestion will produce a band of 4.5 kb.
Second Not I site will be ~900 bp downstream to the mRFP1 3'-end. So, it will produce a band of 1000 bp + 900 bp= 1.9 kb
The residual vector backbone size = ~2 kb
So, three bands are produced = 4.5 Kb + 2 kb + 1.9 Kb

Not I digestion of pKan produces two bands (2250 + 6750)
Not I digestion of pUC19 produces two bands (950 + 1750)