5′-GAATTC-3′
3′- CTTAAG-5′
(a) Name the restriction enzyme that recognizes the given specific sequence of bases. What are such sequences of bases referred to as?
(b) What are the arrows in the given figure indicating? Write the result Obtained thereafter.
Ans. (a) The specific sequence of bases provided, “5′-GAATTC-3′” and its complementary sequence “3′-CTTAAG-5′,” are recognized by the restriction enzyme EcoRI. Such sequences of bases, which are recognized and cleaved by restriction enzymes, are referred to as recognition sites or recognition sequences.
(b) The arrows in the given sequence indicate the specific sites where the DNA is cut by the restriction enzyme EcoRI. EcoRI recognizes the sequence “GAATTC” and cleaves the DNA between the G and the A, resulting in staggered cuts or sticky ends. The result obtained after cleavage is:
5′-G AATTC-3′ 3′-CTTAA G-5′
