What is EcoRI? What does ‘R’ represent in this?

 (a) What is EcoRI? What does ‘R’ represent in this?

(b) Give the palindromic nucleotide sequence recognised by it. 

(c) Explain its action.

Answer (a) Enzyme EcoRI is named as follows :

The capital letter E comes from the genus Escherichia. The letters co are derived from the species name coli. The letter R is from RYI3 (strain). The Roman number I indicates that it
was the first enzyme isolated from the bacterium E. coli RYI3.
(b) EcoRI is a restriction endonuclease enzyme it recognises
base sequences
5′-GAATTC-3′
3′-CTTAAG-5′ in DNA duplex.
(c) It cut each of the two strands between G and A producing sticky ends.