The recognition sequences of four Type-II restriction enzymes $\text{(RE)}$ are given below. The symbol $(\downarrow)$ indicates the cleavage site. Identify the $\text{RE}$ that generates sticky ends.

1. $\text{RE1} – 5’ \text{G}^{\downarrow} \text{GATCC} \; 3’$
2. $\text{RE2} – 5’ \text{CTG}^{\downarrow} \text{CAG} \; 3’$
3. $\text{RE3} – 5’ \text{CCC}^{\downarrow} \text{GGG} \; 3’$
4. $\text{RE4} – 5’ \text{AG}^{\downarrow} \text{CT} \; 3’$