Question

Which of the following DNA sequences is MOST LIKELY to be a restriction enzyme site?

		TAGACT
		CTCGAG
		TTAGCC
		GCTGAC

Answer 1

Restriction enzyme cut DNA at specific Nucleotide sequence called restriction site. Restriction enzymes are specific in restriction site, it have one or few restrictions sites. The restriction sites are mostly palindromic sequences. A palindromic sequence is a nucleotide sequence in a double stranded RNA or DNA in which reading in a certain direction of one strand matches to reading in the same direction of complementary strand. Adenine pairs with thymine (A-T), Guanine with Cytosine (G-C). Restriction enzyme mostly recognize palindrome sequence.

Here 'CTCGAG' is the DNA sequence that most likely to be restriction enzyme to recognize. It's complementary sequence is 'GAGCTC'.