Question

Ive added an image at the bottom of the question with my attempt based on my understanding of the question. can someone please tell me if i have understood the question correctly and if not please explain to me what it actually wants and how to go about completing it.

A plasmid (pUSQ2) is cut with a series of four restriction enzymes (A, B, C and D) and this produces the following bands after submarine gel electrophoresis:      

Enzyme(s)	Bands observed (bp)
A	3000
B	3000
C	500, 2500
D	3000
A + B	250, 2750
A + C	250*, 2500
A + D	1250, 1750
A + C + D	250*, 1000, 1500

                                       (note:  *indicates very intense/bright bands)

On the diagram below, construct a circular plasmid map of the plasmid consistent with the above data, showing:

1. The location of each enzyme cut site
2. The distances between the cut sites

The single enzyme “B” cut site has been marked for you on the map at position “0” and marks have been placed at 500bp intervals around the 3000bp map to assist you.

Type or paste question here

Promo B102107 Cell & Molecular Biology 7. A plasmid (USQ2) is cut with a series of four restriction enzymes (A, B, this produces the following bands after submarine gel electrophoresis: of four restriction enzymes (A, B, C and D) and 15 marks Enzyme(s) Bands observed (bp) 3000 3000 500, 2500 D 3000 A+B 250, 2750 | A+C 250*, 2500 1250, 1750 A+C+D 250, 1000, 1500 (note: * indicates very intense/bright bands) A+D On the diagram below, construct a circular plasmid map of the plasmid consistent with the above data, showing: (i) The location of each enzyme cut site (ii) The distances between the cut sites The single enzyme "B" cut site has been marked for you on the map at position "0" and marks have been placed at 500bp intervals around the 3000bp map to assist you. ' 'B','o' A+B (Ares Arcto) A+C) 2750 c = 200bp A+B= 2500bp ATC=2250be A+0 = 5006 Atero-7506p+ Soope" c 26ev PUS Q2 Total size-3000 bp 1000 / Arcto 200g Ao) (AD) 159 1250 1750 Arcto.

Answer 1

7) As the plasmid DNA is circular & single digestion of enzymes A, B, C & D produce 1, 1, 2 & 1 band respectively, enzymes A, B, C & D will have 1, 1, 2 & 1 restriction site respectively.

From the given date, we find that total size of plasmid DNA will be 3000 bp (We can easily calculate this by adding all the fragments produced by a particular digestion).

According to the question, B cut site has been marked at the position "0".

Also, A+B digestion produces two fragments of 250 & 2750 bp. Now, A cut site can be present left or right of the B cut site. At first, we consider that A cut site is present left of B cut site. Based on this initial plasmid map is drawn below.

AT 250 bp "O" PUSQ2 (3000 bp)

Next, we consider A+C digestion. We find that in this digestion two 250 bp fragments (250* indicates bright brand. We calculate that this will be resulted in two bands) & one 2500 bp fragment is produced. Also, single digestion of C produces two fragments of 500 bp & 2500 bp. So, A cut site must be present in the 500 bp fragment of the only C digestion. Thus, only possibility is that cut site of B & one of the cut site of C are present in the same place. Based on this the map is drawn below.

250 bp | "O" 250 bp PUSQ2 (3000 bp)

Next, we consider A+D digestion. It produces two fragments of 1250 & 1750 bp. If D is present left of the A cut site, then in A+C+D digestion will produce one 750 bp fragment. But from the given data we can't find any 750 bp fragment in A+C+D digestion. So, D cut site must be present right of A cut site. Based on this, final map is drawn below.

250 bp "O 2750. 250 h 1000 bp "2500" PUSQ2 (3000 bp) "1000" 1500 bp Map 1

Now, if A site is present right of B cut site, then we will get an alternate map. This map is drawn below.

250 bp "O" "250" 250 bp "500" 1500 bp PUSQ2 (3000 bp) 1000 bp 1500" Map 2