Question

Luestion 3 1 pts Review: You have the DNA that is radioactively labeled at the S'ends of DNA as shown below. But you want DNA that is labeled only at one end of the DNA, not both ends. One of the other undergraduate students in the lab suggests that you use a restriction enzyme to cut the DNA, then electrophorese the DNA in an agarose gel, then cut out the region of the gel with radioactive DNA fragment you want, and separate the DNA from the agarose gel. Then you would have a radioactive DNA fragment that is labeled at only one end of the DNK Hindini 240 EcoRI 540 Here is a representation of the DNA labeled (red star) at both 5'ends. The DNA fragment is 600 bp in size. You will be testing for protein binding to the promoter sequence that is shown as the black rectangle on the DNA. Various restriction enzyme sites are shown as vertical lines. The numbers under the restriction enzyme name and cutting site indicate nucleotide position on the 600 bp fragment measuring from the left. After cutting with a restriction enzyme and performing agarose gel electrophoresis (shown below), which DNA band, A, B, C, or D will you cut out of the gel to use in your footprinting experiment? Lane 1 is the DNA cut with Hindill. Lane 2 is the DNA cut with EcoRI. You will need to decide which restriction enzyme to use, and predict the size of the fragment that contains the promoter sequence in order to answer correctly. Yes, this is a review of previous concepts in this course. But we are always building on previous concepts. Band A Band B Band C Band D Band A Band B Band Band D MacB

Answer 1

Hind 3 will be used because only one enzyme is to be used and the both the fragments generated after cleaving will have only one radioactive 5' end and they will contain the part of promoter binding sequence.

fragment B and C will be cut out having size 240 and 360 bp