T4 DNA Ligase
T4 DNA Ligase catalyzes the formation of a phosphodiester bond between juxtaposed 5′-phosphate and 3′-hydroxyl termini in duplex DNA or RNA with blunt or cohesive end. The enzyme repairs single-strand nicks in duplex DNA, RNA or DNA/RNA hybrids but has no activity on single-strand nucleic acids. This DNA Ligase requires ATP as a cofactor.
E.coli strain carrying T4 DNA ligase gene
One unit is the amount of enzyme required to give 50% ligation of Hind III fragments of λ DNA (5 ́ DNA termini concentration of 0.12 μM, 200 μg/ml) in a total reaction volume of 20 μl in 30 minutes at 16°C in 1x T4 DNA Ligase Buffer.
Functional absence of endonucleases and exonucleases activities
Applications for T4 DNA Ligase
- Cloning blunt-end or cohesive-end fragments.
- Ligation of synthetic linkers or adaptors.
Storage at -20 °C for one year