EcoRI cuts DNA at the recognition site of 5’-GAATTC-3’ . Draw a diagram to indicate how the DNA will be cut on a double strand and also what sticky ends would look like
Diagram:
Double Strand of DNA:
5' - G A A T T C - 3'
3' - C T T A A G - 5'
After cutting with EcoRI:
5' - G A A T T C - 3'
3' - C T T A A G - 5'
5' - G - 3'
3' - C T T A A - 5'
Sticky Ends:
5' - G A A T T C - 3'
3' - C T T A A G - 5'
5' - G - 3'
3' - C T T A A - 5'
To illustrate how the EcoRI enzyme cuts the DNA at the recognition site 5’-GAATTC-3’, I will provide a step-by-step diagram:
Step 1: Start with the double-stranded DNA molecule, where each strand consists of a chain of nucleotides. The two strands are held together by hydrogen bonds between complementary nitrogenous bases (adenine pairs with thymine and guanine pairs with cytosine).
5'-GAATTC-3'
3'-CTTAAG-5'
Step 2: EcoRI recognizes the specific sequence 5’-GAATTC-3' and binds to this sequence.
GAATTC
CTTAAG
Step 3: Upon binding, EcoRI cuts the DNA strands between the G (guanine) and the A (adenine) nucleotides, indicated by small vertical lines.
GAATTC
CTTAAG
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|
Step 4: This cut results in two fragments of DNA with sticky ends. The sticky ends are single-stranded DNA overhangs at the ends of the fragments, which can base-pair with complementary sticky ends from other DNA molecules.
GAATTC
CTTAA
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|
GTTAAG
Step 5: The cut fragments can now form hydrogen bonds with complementary sticky ends of other DNA fragments or vectors.
GAATTC
CTTAA
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|
GTTAAG
By cutting at the recognition site 5’-GAATTC-3’, EcoRI generates sticky ends that can be used for further molecular biology techniques such as cloning or gene manipulation.