Question

What is Recognition sequence? Explain in brief.

Answer 1

1. The sequences recognized by restriction enzymes are 4 to 8 nucleotides long and characterized by a particular type of internal symmetry is known as recognition sequence.
2. When the sequence is read in opposite direction (3’ to 5’ or 5’ to 3’) it is identical/ same. For e.g. consider the particular sequence recognized by the enzyme EcoRI. 3’ -______ CTTAAG______ 5’ 5’______ GAATTC ______ 3’
3. Restriction enzymes either cut straight across the DNA in the region of palindrome to give blunt ends or cuts producing short, single stranded projections at each end of DNA to produce, cohesive or sticky ends or staggered ends.