Question

(a) Illustrate the recognition sequence of Eco RI and mention what such sequences are called (b) How does restriction endonuclease act on a DNA molecule?

Answer 1

1. 5' G^AATTC 3'

3'CTTAA^G 5'

These sequences are called as palindromic sequences.

2. When a restriction endonuclease recognises a sequence, it snips through the DNA molecule by catalysing the hydrolysis (splitting of a chemical bond by addition of a water molecule) of the bond between adjacent nucleotides.