5′-GGATCC-3′. What is the complementary sequence (3′ to 5′) to the restriction site for BamHI? Enter sequence with the capitalized, one-letter nucleotide code. 5′-GGATCC-3′ 3′- type your answer… -5′
Consider the restriction endonuclease, BamHI, and its restriction site: 5′-GGATCC-3′. What is the complementary sequence (3′ to 5′) to the restriction site for BamHI? Enter sequence with the capitalized, one-letter nucleotide code. 5′-GGATCC-3′ 3′- type your answer… -5′
The Correct Answer and Explanation is:
The complementary sequence to the BamHI restriction site 5′-GGATCC-3′ on the opposite DNA strand can be determined by pairing the bases according to standard base pairing rules.
The sequence given is:
5′-GGATCC-3′
We know that the base pairing rules are as follows:
- Adenine (A) pairs with Thymine (T) in DNA.
- Guanine (G) pairs with Cytosine (C).
So, for the given sequence 5′-GGATCC-3′, the complementary bases on the 3′ to 5′ strand would be:
- G pairs with C
- G pairs with C
- A pairs with T
- T pairs with A
- C pairs with G
- C pairs with G
Thus, the complementary sequence (3′ to 5′) to 5′-GGATCC-3′ would be:
3′-CCTAGG-5′
Explanation:
In the complementary DNA strand, the bases are always paired in this manner:
- A (Adenine) pairs with T (Thymine),
- G (Guanine) pairs with C (Cytosine),
- T (Thymine) pairs with A (Adenine),
- C (Cytosine) pairs with G (Guanine).
The strand 3′-CCTAGG-5′ is complementary to the sequence 5′-GGATCC-3′, adhering to these pairing rules. This complementary strand is important because, during restriction enzyme digestion, the enzyme BamHI recognizes this specific sequence (5′-GGATCC-3′) and cleaves between the G and G residues, leaving sticky ends on the DNA fragments. These sticky ends are crucial for ligation in various molecular biology techniques like cloning and recombinant DNA technology.
