Restriction enzymes

Restriction enzymes derived from bacteria are used in recombinant DNA techniques. The enzyme BamHI cuts DNA in the sequence
G↓
G─A─T─C─C
C─C─T─A─G ↑
G
When used to cut the sequence
5’…ATGGATCCGGACTAA…3’
3’…TACCTAGGCCGGATT…5’
How many DNA fragments are formed?
A) 2 with flat ends
B) 3 with cohesive ends
C) No fragments are formed
D) 2 with cohesive ends
E) 3 with flat ends

The answer is D. Could anyone help?

I think, It must be 3 or the multiples of 3 BUT I’m not sure :slight_smile:
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5’…ATG GATCCGGACTAA…3’
3’…TACCTAG GCCGGATT…5’

Oh, I wasn’t sure of the terminology, but based on your image, it looks like it should be split in two like this and has two sticky ends?

BamH1 uses the same principle as Sma1 in the figure deni_mensur has inserted. It produces sticky ends / cohesive ends.
It cuts between G and A, but not every G and A. This is the point of this question. It does it only in a definite sequence, shown in the question. We have only two sequences of GATCC.

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